WO1993012795A1 - Quinazolin-4(3h)-one derivatives as anticoccidial agents - Google Patents

Abstract

Variously substituted t^_r^_a^_n^_s^_-3-[3-(3-hydroxypiperid-2-yl)-2-oxopropyl]quinazolin-4(3H)-ones, a method of controlling or preventing coccidiosis in poultry therewith, intermediates therefor, and a process for the preparation of certain intermediates therefor.

Description

QUINAZOLIN-4(3H)-ONE DERIVATIVES

AS ANTICOCCIDIAL AGENTS

Background of the Invention

The present invention is concerned with certain trans-3-[3-(3-hydroxy-2-piperidyl)-2-oxopropyl]quinazo- lin-4 (3H)-one derivatives, a method of using same as anticoccidial agents, intermediates therefor, and a process for certain intermediates therefor.

Coccidiosis, a poultry disease, is caused by several species of protozoan parasites of the genus Eimeria, such as E. acervulina and E. tenella. In particular, E. tenella is the causative agent of a severe and often fatal infection of the ceca of chickens which is manifested by extensive hemorrhage, accumulation of blood in the cecum (a pouch between the large and small intestines) and the passage of blood in the droppings. Essentially, coccidiosis is an intestinal disease which is disseminated by birds picking up the infectious organism in droppings on contaminated litter or ground. By damaging the intestinal wall, the host animal is unable to utilize its food, goes off its feed, and in untreated cases the disease terminates in either the death of the animal or the survival of unthrifty birds known commonly as "culls."

Several classes of compounds have been reported to be useful as anticoccidial agents. Among these are various 6-azauracil derivatives (Miller, U.S. Patent 4,239,888; summarizing several additional classes);

trans-3-[3-(3-hydroxy-2-piperidyl)-2-oxopropyl]-4(3H)- quinazolinone (febrifugine; The Merck Index, Tenth

Edition, monograph No. 3881); and trans-7-bromo-6-chloro- 3-[3-(3-hydroxy-2-piperidyl)-2-oxopropyl]-4-(3H)-quinazolinone (halofuginone; The Merck Index, Tenth Edition, monograph No. 4479). Such anticoccidial compounds are more broadly defined by Waletzky et al., U.S. Patent 3,320,124 (Re. 26,833); and Jolly et al., U.S. Patent 4,252,947. European Patent Application 98589 broadly discloses structurally related hydrazine derivatives of trans-3-[3-(3-hydroxy-2-piperidyl)-2-oxopropyl]quinazo- lin-4(3H)-ones as anticoccidial agents.

Structurally related compounds are also reported to be useful in combatting theileriosis in cattle

(Schein, U.S. Patent 4,340,596). Although not in any manner specifically disclosed, the broad genus of Schein can be selectively chosen so as to define instant

6-trifluoromethyl-3-{3-(3-hydroxypiperid-2-yl)-2-oxo- propyl]quinazolin-4(3H)-one. The present anticoccidial activity of that novel species is most surprising in view of the fact that the isomeric 7-trifluoromethyl analog (also defined by Schein's broad genus) is lacking in instant anticoccidial activity.

Structurally related compounds, including broad generic disclosure of 3-[3-(3-hydroxy-2-piperidyl)-2- oxopropyl]quinazolin-4(3H)-ones substituted on the aromatic ring with halogen, trifluoromethyl, lower alkylthio, methoxy, phenoxy and benzyloxy groups, have also been disclosed as antimalarial agents by Baker et al., U.S. Patent 2,694,711; see also Baker et al., U.S. Patents 2,651,632 and 2,796,417 for compounds related to present intermediates. Although not in any manner specifically disclosed, a number of the instantly claimed compounds can be defined by said genera, once having knowledge of the present invention. While Baker et al. ('711) specifically disclose the 5-trifluoromethyl analog

(isomeric with the present 6-trifluoromethyl analog), it is noteworthy that that compound is lacking in present anticoccidial activity. Summary of the Invention

Although above febrifugine and halofuginone are useful as anticoccidial agents, we have determined that a number of related compounds (for example, trams-3-[3- (3-hydroxy-2-piperidyl)-2-oxopropyl]quinazolin-4(3H)- ones substituted on the aromatic ring as follows:

6-phenoxy-7-chloro,

6-(4-hydroxyphenoxy)-7-chloro,

7-(4-bromophenoxy),

7-(4-bromophenoxy)-6-chloro,

5-methylthio,

6-(4-fluorobenzylthio)-7-chloro,

7-cyano,

5-trifluoromethyl,

7-trifluoromethyl, or

8-trifluoromethyl)

are lacking in useful anticoccidial activity in poultry. In spite of such lack of activity, we have surprisingly discovered a number of compounds, very closely related in structure, which are highly active as anticoccidial agents, as determined by their activity against E.

tenella.

Thus the present invention is directed to anticoccidial compounds having the formula

or

wherein

X is fluoro, chloro, bromo or. iodo substituted at the 6- or 7-position;

R is (C₁-C₄)alkylthio;

X ¹ is hydrogen or fluoro, chloro, bromo, iodo or methoxy substituted either at the 7- or at the 8-position; and

R¹ is cyano, trifluoromethyl, (C₁-C₄) alkylthio,

4-picolylthio, 3,5-dichlorophenoxy, / or

where Y¹ is hydrogen, fluoro, chloro, bromo or phenoxy; and Y² is chloro or bromo; with the proviso that Y¹ is other than hydrogen when X¹ is other than hydrogen,

or a pharmaceutically-acceptable acid addition salt thereof.

The compounds of the present invention are racemic (not optically active). The heavy and dotted bonds in the various formulae therefore indicate relative, not absolute, stereochemistry.

Pharmaceutically-acceptable acid addition salts include, but are not restricted to, those with HCl, HBr, H-₂SO₄, CH₃SO₃H, p-CH₃C₆H₄SO₃H, lactic acid, fumaric acid, citric acid and the like.

Most preferred compounds, because of their ease of preparation and high activity, are of the formula (I), particularly those compounds wherein R¹ is methylthio and X¹ is hydrogen, 7-fluoro, 7-chloro or 7-bromo.

The present invention also encompasses a method of controlling or preventing coccidiosis in poultry which comprises administering to said poultry an anticoccidially effective amount of a compound of the formula (I) in drinking water or in nutritionally-balanced feed.

Also claimed are valuable intermediates of the formular

(Ill)

(IV)

wherein

X, R, X¹ and R¹ are as defined above;

R² is hydrogen, acetyl or (C₁-C₄) alkyl; and

R ³ is hydrogen or COOR⁴; where R⁴ is allyl or

(C₁-C₄) alkyl;

with the provi .sos that at least one of R² and R ³ is other than hydrogen, and that R ³ is hydrogen when R² is acetyl; and

(V)

or

wherein

X, R, X¹ and R¹ are as defined above.

In addition, we claim a process for preparing a compound of the formula

or

wherein

R is (C₁ -C₄)alkylthio;

R⁵ and R⁶ are each independently (C₁-C₄) alkyl;

X is fluoro, chloro, bromo or iodo;

R₇ is (C₁-C₄) alkyl, 4-picolyl or

Y² is chloro or bromo; and

X³ is fluoro, chloro, bromo or iodo substituted at the 3- or 4-position;

which comprises:

(a) reaction of a compound of the formula

or

with at least 2 molar equivalents of NH₄SCN in the presence of substantially 1 molar equivalent of Br₂ in a reaction inert solvent comprising a (C₁-C₄) alkanoic acid;

(b) solvolyzing the resulting compound having the formula

or

with at least one equivalent of a nucleophile in a reaction inert solvent comprising water or a (C₁-C₄)- alkanol; and

(c) reacting the resulting thiophenoxide, having the formula

or

with a compound of the formula

R⁶X⁴

or

R⁷X⁴

wherein X ⁴ is a nucleophilically displaceable group, in the same or another reaction inert solvent to form a compound of the formula (VII) or (VIII).

The preferred nucleophile is an alkali metal alkoxide, particularly methoxide. The preferred solvent comprises methanol. Detailed Description of the Invention

The compounds of the present invention are readily prepared by nucleophilic displacement:

(V) or CVI) + (III) or (IV)

(IX)

where in (III), (IV) and (IX) , R² and R⁴ are both defined as above but R² is other than hydrogen, and Y³ is a nucleophilically displaceable group such as chloro, bromo, iodo or mesylate; followed by solvolytic or hydrolytic removal of the groups R² and COOR⁴. Because of their ready availability, preferred compounds of the formula (IX) have Y ³ as bromo, R² as methyl and R⁴ as methyl or allyl.

The nucleophilic displacement reaction between compounds of the formulae (V) or (VI) and (IX) in all cases involves replacement of the leaving group, Y³, with a relatively non-nucleophilic nitrogen. For this reason it is essential to employ a base of sufficient strength to form the anion of the compound (V) or (VI) in an amount at least sufficient to neutralize all of the acid (HY³) coproduced in the reaction. Alkali metal

(C₁-C₄) alkoxides are well suited for this purpose. The reaction is generally carried out in a reaction inert solvent such as a lower alkanol, acetonitrile or

dimethylformamide. The solvent should be less acidic than the compound (V) or (VI), so as to facilitate formation of the required anion. Sodium methoxide as base in methanol as solvent represent conditions particularly well suited for the present reaction. The temperature employed for this reaction is best kept below 40° C.

(e.g., temperatures in the range of 0-30° C. are fully satisfactory). It should be high enough to provide a reasonable rate, but not so high as to lead to undue decomposition. As is well known in the art, rate will vary with the nature of the leaving group (e.g. rate:

I > Br > Cl), the specific structure of the compound

(V) or (VI), the concentration of reagents and the solvent. The reaction time should be such that the reaction is nearly complete [e.g. >95% conversion when equivalent amounts of the compounds (V) or (VI) and

(IX) are employed] to maximize yields le.g. reaction times 1 hour to several hours at ambient temperature are well suited when Y³ is bromo, the base is sodium methoxide, the solvent is methanol, and the concentration of compound (IX) is in the range 3-10% (w/v)]. Of course, complete reaction can be facilitated by use of an excess of one of the reagents, e.g. an excess of the compound (V) or (VI) when it is the more readily avail- able of the two reagents.

The present nucleophilic displacement reactions produce compounds of the above formula (III) or (IV) wherein R² is (C₁-C₄) alkyl and R is COOR⁴ (where R⁴ is defined above). The groups R² and COOR⁴ are readily removed, stepwise or in a single step, to produce the desired compounds of the formula (I) or (II). Thus the (C₁-C₄) alkyl ether group is conveniently and selectively removed by the action of BBr₃ in a reaction inert solvent at a temperature ranging from -70° to 0° C.

Methylene chloride as solvent is particularly well suited for this purpose, since solutions of BBr₃ therein are commercially available. This method produces intermediate compounds of the formula (III) or (IV) wherein R² is hydrogen. The COOR⁴ group is then conveniently removed from the latter intermediates by briefly heating with concentrated aqueous HBr, e.g. heating in 48% HBr for 2 to 10 minutes at 80-150° C.; heating in 6N HCl at or near reflux temperature; or concentrated HBr in glacial acetic acid at 0-30° C. The latter process generally produces the compound (III) or (IV) wherein

R ³ is hydrogen and R² is generally acetyl. The latter is removed by mild hydrolysis, e.g., 6N HCl at 10-30° C.

Alternatively, the groups R² and R ³ are removed in reverse order, using 33% HBr in acetic acid at 10-30° C. to remove the group R³, followed by heating at or near reflux in 48% aqueous HBr to remove the group R²; or both groups R² and R ³ are concurrently removed by use of the latter 48% HBr conditions.

The acid addition salts of the compounds of the present invention, if not directly isolated, for example, as the hydrobromide salt directly from the reaction mixture, are obtained by contacting the free base with at least one equivalent of the appropriate acid in a reaction inert solvent. Those salts which do not

precipitate directly are isolated by concentration and/or the addition of a non-solvent. Conversely, the free base form is conveniently formed from an acid addition salt by neutralization of the latter in water with recovery of the free base by filtration or extraction into a water immiscible organic solvent.

The required starting compounds of the formula (V) or (VI) are generally prepared by methods known in the chemical art. Some of the required starting 2-amino- benzoic acids or esters required in the synthesis of the compounds (V) and (VI) are known, or accesible by known methods. Others, in particular those of the above formula (VII) or (VIII) are now more practically accessible via the presently discovered, improved process for their preparation, as summarized above and as detailed in specific preparations below.

The cocciodiostatic activity of the compounds of the present invention is demonstrated as follows.

Groups of chicks (e.g. groups of five ten-day old SPF white Leghorn cockerels) are fed a nutritionally complete basal ration into which the test compound is incorporated at various concentrations. The basal ration is generally a commercial chick starter (e.g. Agway Commercial Chick Starter, available from the Agway Feed Co., Franklin, Connecticut), and is presented ad libitum to the chicks 24 hours before infection and continuously thereafter throughout the course of the tests.

Twenty-four hours after initiation of the medication the chicks are inoculated orally with 100,000 sporulated oocysts (Eimeria tenella) and the average weight per bird per group determined. In addition, a group of six chicks is fed the basal ration which contains none of the test compound (infected, untreated controls). A further group of six chicks serves as uninfected, untreated controls. The chicks are examined on the fifth and sixth day post-infection for signs of hemorrhage. On the sixth day post-infection, the average body weight per bird per group is determined, the birds necropsied, the cecum examined macroscopi- cally, and a pathology index (average degree of infection [A.D.I.]) determined. Chicks which die prior to the fifth day post-infection are considered as toxic deaths. Those which die five days post-infection or later are considered as deaths due to disease. The degree of pathologic involvement at necropsy is expressed as the average degree based on the following scheme: 0 = no cecal lesions; 1 = slight lesions;

2 = moderate lesions; 3 = severe lesions; 4 = death.

The efficacy of the test compound, at a given level in feed, is judged by comparison of the pathologic index with that of the unmedicated infected controls, expressed as the ratio:

A.D.I, (treated group)

A.D.I, (infected, untreated controls)

Against E. tenella, the compounds of the present invention generally show a value of said ratio no higher than 0.6 at a feed concentration no higher than 25 p.p.m.

The typical range of results obtained with the compounds of the present invention are illustrated as follows:

Ratios at Feed

Com ound Concentration m

It will be noted that a ratio of 0.0 indicates 100% control of pathology due to the infection at the indicated feed concentration. The compounds of this invention are orally administered to poultry in a suitable carrier. Conveniently, the medication is simply carried in the drinking water or in the poultry feed, so that a therapeutic dosage of the agent is ingested with the daily water or poultry ration. The agent can be directly metered into drinking water, preferably in the form of a liquid, water- soluble concentrate Csuch as aqueous solution of a water soluble salt) or added directly to the feed, as such, or in the form of a premix or concentrate. A premix or concentrate of therapeutic agent in a carrier is commonly employed for the inclusion of the agent in the feed.

Suitable carriers are liquid or solid, as desired, such as water, various meals (for example, soybean oil meal, linseed oil meal, corncob meal), and mineral mixes such as are commonly employed in poultry feeds. A particularly effective carrier is the poultry feed itself; that is, a small portion of poultry feed. The carrier facilitates uniform distribution of the active materials in the finished feed with which the premix is blended. This is important because only small proportions of the present potent agents are required. It is important that the compound be thoroughly blended into the premix and, subsequently, the feed. In this respect, the agent may be dispersed or dissolved in a suitable oily vehicle such as soybean oil, corn oil, cottonseed oil, and the like, or in a volatile organic solvent and then blended with the carrier. It will be appreciated that the proportions of active material in the concentrate are capable of wide variation since the amount of agent in the finished feed may be adjusted by blending the appropriate proportion of premix with the feed to obtain a desired level of therapeutic agent. High potency concentrates may be blended by the feed manufacturer with proteinaceous carrier such as soybean oil meal and other meals, as described above, to produce concentrated supplements which are suitable for direct feeding to poultry. In such instances, the poultry are permitted to consume the usual diet. Alternatively, such concentrated supplements may be added directly to the poultry feed to produce a nutritionally balanced, finished feed containing a therapeutically effective level of one or more of the compounds of this invention. The mixtures are thoroughly blended by standard procedures, such as in a twin shell blender, to ensure homogeneity.

It will, of course, be obvious to those skilled in the art that the use levels of the compounds

described herein will vary under different circumstances. Continuous low-level medication, during the growing period; that is, during the first 6 to 12 weeks for chickens, is an effective prophylatic measure. In the treatment of established infections, higher levels may be necessary to overcome the infection. The use level in feed will generally be in the range of 3 to 100 ppm. Mien administered in drinking water, the level which will be that which will provide the same daily dose of medication, i.e. 3 to 100 ppm, factored by the weight ratio of the average daily consumption of feed to the average daily consumption of water.

The present invention is illustrated by the following examples. However, it should be understood that the invention is not limited to the specific details of these examples. EXAMPLE 1

Allyl trans-2-[3-(7-chloro-6-(4-chlorophenoxy)- quinazolin-4(3H)-on-3-yl)-2-oxopropyl]-

3-methoxypiperidine-1-carboxylate

[Formula (IV) with X¹ = 7-chloro, R¹ = 4-chlorophenoxy, R² = methyl and R⁴ = allyloxycarbonyl]

Under a nitrogen atmosphere in a flame-dried flask at room temperature and with magnetic stirring, 0.921 g

(0.003 mol) of 7-chloro-6-(4-chlorophenoxy)quinazolin- 4(3H)-one was slurried in 3.0 ml of 1.1N sodium methoxide, After 15 minutes, 1.00 g (0.003 mol) of allyl trans-2- (3-bromo-2-oxopropyl)-3-methoxy-1-piperidinecarboxylate in 10 ml of methanol was added dropwise. After 2 hours, the reaction mixture was evaporated under reduced

pressure, and the residue treated with water. The

aqueous solution was extracted three times with 75 ml of dichloromethane. The combined extracts were dried over anhydrous magnesium sulfate, filtered, and evaporated to afford the title compound: yield 1.28 g (76%); m.p. 138-141° C. H-NMR(CDCl₃): 1.3 to 1.9 (m, 4H),

2.6-3.4 (m, 6H), 3.3 (s, 3H), 4.9 (s, 2H), 4.5-6.2 (m, 5H), 7.1 (q, 4H), 7.6 (s, 1H), 7.8 (d, 2H) ppm.

By the same method, other suitably substituted

6-phenoxyquinazolin-4(3H)-ones were converted to allyl trans-2-[3-(7-X¹ substituted)-6-(Y¹ substituted phenoxy)- quinazolin-4(3H-)-on-3-yl]-2-oxopropyl]-3-methoxypiperidine-1-carboxylates as follows:

(a),

1H-NMR(CDCl₃) delta: 1.4-2.0 (m, 4H), 2.6-3.6 (m,

6H), 3.3 (s, 3H), 5.2 (s, 2H), 4.5-6.2 (m, 5H),

6.9-7.9 (m, 8H) ppm;

(b) ¹H-NMR(CDCl₃), like that of the 4-chlorophenoxy analog, is consistent with the assigned structure.

EXAMPLE 2

trans-7-Chloro-6-(4-chlorophenoxy)-3-

[3-(3-methoxypiperid-2-yl)-2-oxopropyl]- quinazolin-4(3H)-one Dihydrobromide

[Compound (IV) with X¹ = chloro, R¹ = 4-chlorophenoxy, R² = methyl and R³ = hydrogen]

A solution of 1.15 g (0.002 mol) of the title product of the preceding Example in 50 ml of 33% hydrobromic acid in acetic acid was stirred at room temperature for 45 minutes. The solvent was evaporated under reduced pressure and the residue triturated with ethanol. The resulting suspension was filtered to afford the present title compound as a white solid: m.p. 229- 231° C..; yield 0.897 g (68%).

By the same method, the other compounds of the preceding Example were converted to the corresponding dihydrobromide salts of trans-7-(X¹ substituted)-6-(Y¹-substituted phenoxy)-3-[3-(3-methoxypiperidin-2-yl)-2-oxopropyl]quinazolin-4(3H)-ones as follows:

*¹H-NMR(DMSO-d₆) delta: 1.3-2.1 (m, 4H) , 2.9-3.6 (m, 6H) , 3.4 (s, 3H) , 5.2 (s, 2H) , 7.0-7.8 (m, 7H) , 8.4 (s, 1H).

EXAMPLE 3

trans-7-Chloro-6-(4-chlorophenoxy)-3-

[3-(3-hydroxypiperid-2-yl)-2-oxopropyl]- quinazolin-4(3H)-one Dihydrobromide

[Formula (II) with X¹ = 7-chloro and R¹ = 4-chloro- phenoxy]

A solution of 0.80 g (0.0012 mol) of the title product from the preceding Example in 40 ml of 48% hydrobromic acid was heated at reflux for 15 minutes. The reaction mixture was cooled to room temperature and evaporated to an oil under reduced pressure. The residue was treated with several ml of ethanol and the resulting solution was evaporated. This operation was repeated several times. Finally, the residue was taken up in hot ethanol and the product crystallized upon cooling to room temperature. Filtration gave the title compound: m.p. 185-188° C.; yield 0.674 g (86%).

Analysis calculated for C₂₂H₂₁Cl₂N₃O₄ ·2HBr ·1/2H₂O:

C, 41.73; H, 3.82; N, 6.64%. Found: C, 41.74; H, 3.80, N, 6.75%.

By the same method the other products of the preceding Example were converted to corresponding dihydrobromide salts of trans-7-(X¹ substituted)-6-(Y¹ substituted phenoxy-3-[3-(3-hydroxypiperid-2-yl)-2-oxo- propylquinazolin-4(3H)-ones as follows:

(a)

¹³C-NMR(DMSO-d₆) : 20.307, 30.817, 43.155, 54.537, 56.379, 66.768, 112.46, 121.185, 122.213, 126.232, 128.227, 129.336, 130.123, 143.252, 147.019, 154.575, 155.508, 159.215, 200.448.

(b),

1H-NMR(DMSO-d₆) : 1.5-2.1 (m, 4H) , 2.9-3.8 (m, 6H) ,

5.2 (s, 2H) , 7.2-7.9 (m, 6H) , 8.4 (s, 1H) .

EXAMPLE 4

Allyl trans-2-[3-(7-Bromo-6-methylthio- quinazolιn-4(3H)-on-3-yl)-2-oxopropyl]-

3-methoxy-1-piperidinecarboxylate Under a nitrogen atmosphere in a flame dried flask at room temperature and with magnetic stirring, a suspension of 0.43 g (0.00136 mol) of 7-bromo-6-methyl- thioquinazolin-4(3H)-one formic acid salt in 5 ml of methariol was treated with two equivalents of sodium methoxide in methanol (approximately 1N). After 15 minutes 0.53 g (0.0016 mol) of allyl trans-2-(3-bromo- 2-oxopropyl)-3-methoxy-1-piperidinecarboxylate was added in one portion. After being stirred for an hour, the reaction mixture was evaporated under reduced pressure, and the residue was taken up in about 15 ml of water. The aqueous solution was extracted three times with 15 ml portions of dichloromethane. The combined extracts were dried over anhydrous sodium sulfate, filtered, and evaporated to afford the title compound: yield 0.61 g (86%). ¹H-NMR(CDCl₃): 1.3-2.0 ppm (multi- plet, 4H, CH₃OCHCH₂CH₂CH₂N), 2.6 (singlet, 3H, CH S),

2.8-3.0 (multiplett 4H, COCH₂CH and NCH₂), 3.3 (broad

singlet, 1H, CH₂CHNCO), 3.4 (singlet, 3H, CH₃O), 4.0

(broad doublet, 1H, CHOCH ), 4.6 (broad doublet, 2H, CH₂CH=CH₂), 4.8-5.1 (multiple peaks, 2H, NCH₂CO), 5.2-

5.4 (multiplet, 2H, CH₂=CH), 5.9 (octet, 1H CH=CH₂),

7.3 (singlet, 1H, aromatic H), 7.9 (singlet, 1H,

aromatic H), 7.95 (singlet, 1H, N=CH-N). EXAMPLE 5

trans-7-Bromo-3-[3-(3-methoxypiperid- 2-yl)-2-oxopropyl]-6-methylthio- quinazolin-4(3H)-one Dihydrobromide A solution of 0.61 g (0.00116 mol) of the title product of the preceding Example and 30 ml of 33% hydrobromic acid in acetic acid was stirred at room temperature for 30 minutes. The solution was evaporated under reduced pressure and treated with a few ml of ethanol. The ethanolic solution was evaporated, and the residue was treated again with ethanol. Again the solution was evaporated. Ethanol was added a final time. After standing overnight at room temperature the solution afforded the present title compound as a crystalline material: m.p. 250-253° C.; yield 0.11 g (16%); mass spectrum m/e 440 (molecular ion + 1), 407 (-32, -CH₃OH), 137 (parent peak) amongst others.

EXAMPLE 6

trans-7-Bromo-3-[3-(3-hydroxypiperid-

2-yl)-2-oxopropyl]-6-methylthio quinazolin-4(3H)-one Dihydrobromide In a 25 ml round bottom flask, a solution of

0.175 g (0.00029 mol) of the title product of the preceding Example and 10 ml of aqueous 48% hydrobromic acid was immersed in an oil bath preheated to 150° C.

Heating was continued for 15 minutes. After cooling to nearly room temperature, the reaction mixture was evaporated under reduced pressure. The residue was treated with a few ml of ethanol, and the resulting solution was evaporated. This operation was repeated. Finally the residue was taken up in 50 ml of hot ethanol, and fil- tered to remove some insoluble matter. The filtrate was concentrated to about 2 ml. Crystals formed and were filtered to give the instant title compound: yield 0.107 g (63%); high resolution mass spectrum m/e 425.0397 (molecular ion with isotope at 427.0416, theory 425.0408) ¹H-NMR(DMSO-d₆) 1.4-2.0 ppm (multiplet, 4H,

HOCHCH₂CH₂CH₂N), 2.6 (singlet, 3H, SCH₃), 2.8-3.0 (mul

tiplet, 2H, NCH₂), 3.1-3.6 (multiplet,4H, CH₂N, CHOH,

CH₂CHN), 5.1 (singlet, 2H, NCH₂CO), 5.6 (doublet, 1H,

OH), 7.8 (singlet, 1H, aromatic H)H , 8.0 (singlet, 1H, aromatic H), 8.2 (singlet, 1H, N=CH-N).

EXAMPLE 7

Allyl trans-2-[3-(7-Bromo-6-ethylthio- quinazolin-4(3H)-on-3-yl)-2-oxopropyl]- 3-methoxy-1-piperidinecarboxylate In the manner of Example 4, 0.743 g (0.00224 mol) of 7-bromo-6-ethylthioquinazolin-4(3H)-one formic acid salt and 0.750 g (0.00224 mol) of allyl trans-2-(3- bromo-2-oxopropyl)-3-methoxy-1-piperidinecarboxylate were converted into the title compound. After flash chromatography on silica gel (eluant 3% methanol in chloroform) there was obtained the pure product: · yield 0.61 g (51%); mass spectrum m/e 537 (molecular ion with expected isotope pattern), 41 (parent peak, CH =CH-CH₂+) among others. ¹H-NMR(CDCl₃) 1.4 ppm (triplet, 3H, SCH₂CH₃), 1.4-2.1 (multiplet, 4H, OCHCH₂CH₂CH₂N), 2.8- 3.4 (

multiplet, 6H, NCH₂, SCH₂CH₃, COCH₂CH), 3.4

(singlet, 3H, OCH₃), 4.0 (broad single

t, 1H, CHNCO),

4.6 (doublet, 2H, CH₂CH=CH₂), 5.0 (singlet, 2H, NCH₂CO),

5.0-5.5 (multiplet, 2H, CH=CH₂), 5.6-6.1 (octet, 1H, CH₂=CH), 7.3 (singlet, 1H, a

romatic H), 7.9 (singlet, 2H, aromatic H, N=CH-N).

EXAMPLE 8

trans-7-Bromo-3-[3-(3-methoxypiperid-

2-yl)-2-oxopropyl]-6-ethylthio- quinazolin-4(3H)-one Dihydrobromide

In the manner of Example 5, 0.61 g (0.00113 mol) of the title product of the preceding Example was transformed into present title compound: yield 0.316 g

(45%); m.p. 225-228° C.; mass spectrum m/e 454 (molecular ion + H with expected isotope pattern), 421 (-32, -CH₃OH), 137 (parent peak) among others. ¹H-NMR(DMSO-d₆) 1.35 ppm (triplet, 3H, SCH₂CH₃), 1.4-2.2 (multiplet,

4H, OCHCH₂CH₂CH₂N), 2.9-3.1 (multiplet, 2H, CH₂N), 3.1-

3.3 (multlpϊet

, 5H, SCH₂CH₃, COCH₂CH) 3.3 (s

inglet, 3H,

OCH₃), 3.6 (broad singlet, 1H, C

H₃OCH), 5.1 (singlet,

2H,NCH₂CO), 7.9 (singlet, 1H , aromatic H), 8.0 (singlet, 1H, ar

omatic H), 8.2 (singlet, 1H, N=CH-N).

EXAMPLE 9

trans-7-Bromo-3-[3-(3-hydroxypiperid- 2-yl)-2-oxopropyl]-6-ethylthio- quinazolin-4(3H)-one Dihydrobromide

In the manner of Example 6, 0.31 g (0.00058 mol) of title product of the preceding Example was converted to present title compound: yield 0.263 g (87%); mass spectrum m/e 439 (molecular ion with expected isotope pattern), 421 (-18, -H O), 137, 96, 82 (parent peak) among others. ¹H-NMR(DMSO-d₆) 1.35 ppm (triplet, 3H, SCH₂CH₃), 1.4-2.0 (multiplet, 4H, OCHCH₂CH₂CH₂N), 2.8- 3.0 (

multiplet, 2H, NCH₂), 3.1-3.6 (mu

ltiplet, 6H,

SCH₂CH₃, COCH₂CHCHO), 5.1 (singlet, 2H, NCH₂CO), 7.9

(singlet, 1H

aromatic H), 8.0 (singlet, 1H, aromatic H), 8.2 (singlet, 1H, N=CH-N). EXAMPLE 10

Allyl trans-2-[3-(7-Fluoro-6-methylthio- quinazolιn-4(3H)-on-3-yl)-2-oxopropyl]- 3-methoxy-1-piperidinecarboxylate

In the manner of Example 4, 0.462 g (0.0018 mol) of 7-fluoro-6-methylthioquinazolin-4(3H)-one formic acid salt and 0.750 g (0.00224 mol) of allyl trans-2-(3- bromo-2-oxopropyl)-3-methoxy-1-piperidinecarboxylate were converted into the title compound: yield 0.50 g (60%). 1H-NMR(CDCl₃) 1.4-2.1 ppm (multiplet, 4H, OCHCH₂CH₂CH₂N) , 2.6 (singlet, 3H, SCH₃), 2.8-3.4 (multiplet, 4

H, NCH COCH₂CH), 3.4 (singl

it, 3H, OCH₃), 4.0 .(broad singlet,

1H, CHNCO), 4.6 (doublet, 2H,

CH₂CH=CH₂), 5.0 (singlet, 2H, NCH₂CO), 5.0-5.5 (multiplet

, 2H, CH=CH₂), 5.6-6.1 (octet

, 1H, CH₂=CH), 7.3 (doublet, 1H, ar

omatic H), 7.9

(singlet, 1H, N=CH-N), 8.0 (doublet, 1H, aromatic H).

EXAMPLE 11

trans-7-Fluoro-3-[3-(3-methoxypiperid- 2-yl)-2-oxopropyl]-6-methylthio- quinazolin-4(3H)-one Dihydrobromide

In the manner of Example 5, 0.48 g (0.001 mol) of the title product of the preceding Example was transformed into the instant title compound: yield 0.324 g (58%); m.p. 214-216° C.

EXAMPLE 12

trans-7-Fluoro-3-[3-(3-hydroxypiperid- 2-yl)-2-oxopropyl]-6-methylthio- quinazolin-4(3H)-one Dihydrobromide

In the manner of Example 6, 0.32 g (0.00059 mol) of the title product of the preceding Example was converted to present title compound: yield 0.188 g (60%); mass spectrum m/e 366 (molecular ion + H), 347 (-18,

-H₂O), 137 (parent peak) among others. ¹H-NMR(DMSO-d₆) 1.4-2.1 ppm (multiplet, 4H, OCHCH₂CH₂CH₂N), 2.6 (singlet,

3H, SCH₃), 2.8-3.0 (multiplet, 2H, NCH₂), 3.1-3.7

(multi

plet, 4H, COCH₂CHCHO), 5.1 (singϊet, 2H, NCH₂CO), 7.5 (doublet, 1H, a

romatic H), 7.9 (doublet, 1H,

aromatic H), 8.3 (singlet, 1H, N=CH-N), 8.9 (broad singlet, 2H, NH₂).

EXAMPLE 13

Allyl trans-2-[3-(7-Iodo-6-methylthio- quinazolin-4(3H)-on-3-yl)-2-oxopropyl]- 3-methoxy-1-piperidinecarboxylate

In the manner of Example 4, 1.09 g (0.003 mol) of

7-iodo-6-methylthioquinazolin-4(3H)-one formic, acid salt and 1.0 g (0.003 mol) of allyl trans-2-(3-bromo-2-oxo- propyl)-3-methoxy-1-piperidinecarboxylate were converted into the title compound: yield 0.53 g (31%); mass spectrum m/e 571 (molecular ion), 539 (-32, -CH..OH),

221 (parent peak). ¹H-NMR(CDCl₃) 1.4-2.1 ppm (multiplet, 4H, OCHCH₂CH₂CH₂N) , 2.6 (singlet, 3H, SCH₃), 2.8-3.4

(multiplet, 4H, NCH₂, COCH₂CH), 3.4 (singlet, 3H, OCH ), 4.0 (broad singlet,

lH, CHNCO), 4.6 (doublet, 2H,

CH₂CH=CH₂), 5.0 (singlet, 2H, NCH₂CO), 5.0-5.5 (multi

plet, 2H, CH=CH₂), 5.6-6.1 (octe

t, 1H, CH₂=CH), 7.7

(singlet, 1H, aromatic H), 7.8 (singlet, 1H, N=CH-N), 8.2 (singlet, 1H, aromatic H).

EXAMPLE 14

trans-7-Iodo-3-[3-(3-methoxypiperid-

2-yl)-2-oxopropyl]-6-methylthio- quinazolin-4(3H)-one Dihydrobromide

In the manner of Example 5, 0.53 g (0.00093 mol) of title product of the preceding Example was trans- formed into instant title compound: yield 0.264 g (44%); m.p. 210-230° C.; mass spectrum m/e 488 (molecular ion + H+), 469 (-18, -H₂O?), 455 (-32, -CH₃OH), 137 (parent peak among others. ¹H-NMR(DMSO-d₆) 1.2-2.0 ppm (multiplet, 4H, OCHCH₂CH₂CH₂N), 2.6 (singlet, 3H, SCH₃), 2.8- 3.0 (multiplet

, 2H, NCH₂), 3.1-3.7 (multiplet,

4H,

COCH₂CHCHO), 3.3 (singlet, 3H, OCH₃), 5.1 (singlet, 2H,

NCH₂CO), 7.7 (singlet, 1H, aromatic H), 8.2 (singlet,

1H, aromatic H), 8.25 (singlet, 1H, N=CH-N), 8.7

(broad singlet, 2H, NH₂). EXAMPLE 15

trans-7-Iodo-3-[3-(3-hydroxypiperid- 2-yl)-2-oxopropyl]-6-methylthio- quinazolin-4(3H)-one Dihydrobromide In the manner of Example 6, 0.262 g (0.0004 mol) of title product of the preceding Example was converted to the title compound: yield 0.234 g (91%); mass spectrum m/e 473 (molecular ion), 455 (-18, -H₂O),

318 (parent peak) among others. ¹H-NMR(DMSO-d₆) 1.2- 2.0 ppm (multiplet, 4H, OCHCH₂CH₂CH₂N), 2.6 (singlet,

3H, SCH₃), 2.8-3.0 (multiplet, 2H, NCH₂) , 3.1-3.6

(multiplet, 4H, COCH₂CHCHO), 5.1 (singlet, 2H, NCH₂CO),

7 .7 (singlet, 1H, aromatic H), 8.2 (singlet, 1H, aromatic H), 8.25 (singlet, 1H, N=CH-N), 8.7 (broad singlet, 2H, NH₂).

EXAMPLE 16

Allyl trans-2-[3-(6-Chloro-7-methylthio- quinazolιn-4(3H)-on-3-yl)-2-oxopropyl]- 3-methoxy-1-piperidinecarboxylate

In the manner of Example 4, 0.679 g (0.003 mol) of 6-chloro-7-methylthioquinazolin-4(3H)-one and 1.0 g

(0.003 mol) of allyl trans-2-(3-bromo-2-oxopropyl)- 3-methoxy-1-piperidinecarboxylate were converted into the title compound: yield 0.56 g (39%). ¹H-NMR(CDCl₃) 1.4-2.2 ppm (multiplet, 4H, OCHCH₂CH₂CH₂N), 2.6 (singlet,

3H, SCH₃), 2.8-3.4 (multiplet, 4H, NCH₂, COCH_HCH), 3.4

(singlet, 3H, OCH₃) , 4.0 (broad singlet, 1H, CHNCO),

4.6 (doublet, 2H,CH₂CH=CH₂) , 5.0 (singlet, 2H, NCH₂CO),

5.0-5.5 (multiplet, 2H, CH=CH₂), 5.6-6.1 (octet, 1H,

CH₂=CH), 7.4 (singlet, 1H, aromatic H), 7.9 (singlet,

1H, N=CH-N), 8.2 (singlet, 1H, aromatic H). EXAMPLE 17

trans-6-Chloro-3-[3-(3-methoxypiperid-

2-yl)-2-oxopropyl]-7-methylthio- quinazolin-4(3H)-one Dihydrobromide in the manner of Example 5, 0.56 g (0.00118 mol) of title product of the preceding Example was transformed into the present title compound: yield 0.27 g (41%); m.p. 225-255° C.; mass spectrum m/e 396

(molecular ion + H+), 363 (-32, -CH OH), 137 (parent peak) among others; ¹H-NMR(DMSO-d₆) 1.4-1.9 ppm

(multiplet, 4H, OCHCH₂CH₂CH₂N), 2.6 (singlet, 3H, SCH₃),

2.8-3.0 (multiplet, 2H, NCH₂), 3.1-3.7 (multiplet, 4H,

COCH₂CHCHO), 3.3 (singlet,3H, OCH ), 5.1 (singlet,

2H,NCH₂CO), 7.5 (singlet, 1H, aromatic H), 8.1 (singlet,

1H, aromatic H), 8.25 (singlet, 1H, N=CH-N), 8.7 (broad singlet, 2H, NH₂).

EXAMPLE 18

trans-6-Chloro-3-[3-(3-hydroxypiperid- 2-yl)-2-oxopropyl]-7-methylthio- quinazolin-4(3H)-one Dihydrobromide

In the manner of Example 6, 0.26 g (0.000546 mol) of title product of the preceding Example was converted to the instant title compound: yield 0.104 g (35%);

high resolution mass spectrum m/e 363.0835 (molecular ion -18, -H₂O); ¹H-NMR(DMSO-d₆) 1.4-2.0 ppm (multiplet, 4H, OCHCH₂CH₂CH₂N), 2.6 (singlet, 3H, SCH₃), 2.8-3.0 (multipl

et, 2H, NCH₂), 3.1-3.6 (multiplet, 4H,

COCH₂CHCHO), 5.1 (singlet, 2H, NCH₂CO), 7.5 (singlet, 1H,

aromatic H), 8.1 (singlet, 1H7 aromatic H), 8.25 (singlet, 1H, N=CH-N), 8.7 (broad singlet, 2H, NH₂).

EXAMPLE 19

Allyl trans-2-[3-(6-Substituted- 7- or

8-substιtuted-quinazolin-4(3H)-on-3-yl)-

3-methoxypiperidine-1-carboxylates

By the method of Example 4, equivalent amounts of the appropriately substituted quinazolin-4(3H)-one and allyl trans-2-(3-bromo-2-oxopropyl)-3-methoxy-1- piperidine-1-carboxylate were converted to the following title products substituted as follows:

(a)

¹H-NMR(CDCl₃): 1.4-2.1 (m, 4H), 2. ,6 (s, 3H), 2.8-3.6

(m, 6H), 3.5 (s, 3H), 4.6-6.3 (m, 5H), 5.0 (s, 2H), 7.6-8.1 (m, 4H).

(b)

¹H-NMR consistent with assigned structure, having key features as in footnote (a).

(c) tlc Rf 0.82 (9:1 CHCl₃ :CH₃OH).

EXAMPLE 20

Allyl trans-2-[3-(7-Chloro-6-[4-bromobenzyl- thio]quιnazolin-4(3H)-on-3-yl)-2-oxopropyl]- 3-hydroxypiperidine-1-carboxylate

A solution of 0.55 g (0.87 mmol) of the 6-(4-bromo- benzylthio)-7-chloro product of the preceding Example in 20 ml of dichloromethane was cooled to -15° C. under argon. While stirring, 4.4 ml of 1.0M boron tribromide in dichloromethane was added dropwise by syringe. The reaction was stirred 30 minutes at -15° C., allowed to warm to 20° C., and stirred an additional 30 minutes. The solution was then poured into 50 ml of saturated aqueous sodium bicarbonate. The aqueous phase was extracted five times with 50 ml portions of dichloro- methane. The extracts were combined with the organic layer, dried over anhydrous magnesium sulfate, and evaporated to yield the title compound as an oil:

yield 0.511 g (95%). This material was used without further purification in the procedure of the next

Example.

EXAMPLE 21

trans-7-Chloro-3-[3-(3-hydroxypiperid- 2-yl)-2-oxopropyl]-6-(4-bromobenzylthio)- quinazolin-4(3H)-one Dihydrochloride

A suspension of 0.50 g (0.8 mmol) of the product from the preceding Example in 25 ml of 6N hydrochloric acid was heated at reflux for 30 minutes. The solvent was evaporated and the residue recrystallized from ethanol to afford the title compound as a solid: m.p. 190-193° C..; yield 137 mg (28%). EXAMPLE 22

Other Allyl trans-2-[3-(6-Substituted- 7-Substituted-quιnazolin-4(3H)-on-3-yl)- 2-oxopropyl]-3-hydroxypiperidine-1-carboxylates

By the method of Example 20, the appropriately substituted products of Example 19 were converted to title products substituted as follows:

EXAMPLE 23

trans-7-Chloro-3-[3-(3-hydroxypiperid- 2-yl)-2-oxopropyl]-6-(4-picolylthio)- quinazolin-4(3H)-one Dihydrochloride

By the method of Example 21, the 6-(4-picolylthio)- 7-chloro intermediate of the preceding Example was converted to instant title product as a foam in 61% yield; tic Rf 0.48 (10:2:1 CHCl₃ :ethanol:cone. NH₄OH).

EXAMPLE 24

trans-7-Chloro-3-[3-(3-hydroxypiperid- 2-yl)-2-oxopropyl]-6-(4-chlorobenzylthio)- quinazolin-4(3H)-one Dihydrobromide Using the conditions of Example 3 (refluxing 48%

HBr) the 6-(4-chlorobenzylthio)-7-chloro product of

Example 22 was converted to the instant title product, m.p. 260-263° C., in 47% yield.

EXAMPLE 25

trans-7-Methoxy-3-[3-(3-hydroxypiperid- 2-yl)-2-oxopropyl]-6-methylthioquin- azolin-4(3H)-one Dihydrobromide

By heating in 48% HBr at 100° C. for 12 minutes, the 6-methylthio-7-methoxy product of Example 22 was converted to the instant title product, isolated in

69% yield as a foam having ¹H-NMR(DMSO-d₆) 1.4-2.3

(m, 4H), 2.5 (s, 3H), 2.9-3.8 (m, 6H), 4.0 (s, 3H),

5.2 (s, 2H), 7.2 (s, 1H), 7.7 (s, 1H), 8.5 (s, 1H).

EXAMPLE 26

Other trans-6-Substituted-7- or 8-substituted-

3-[3-(3-methoxypiperid-2-yl)-2-oxopropyl]- quinazolin-4(3H)-one Dihydrobromides

By the method of Example 5, other products of

Example 19 were converted to the instant title products substituted as follows:

a

1 H-NMR(CF₃CO₂H) 1.2 (t, 3H), 1.4-2.4 (m, 6H), 3.2 (t, 2H), 3.6 (s, 3H), 5.6 (s, 2H), 7.8-8.4 (m, 4H).

EXAMPLE 27

Other trans-6-Substituted-7- or 8-substituted-

3-[3-(3-hydroxypiperid-2-yl)-2-oxopropyl]- guinazolin-4(3H)-one Dihydrobromides

By the method of Example 6, the products of the preceeding Example are converted to title products substituted as follows:

(a)

1³ C-NMR(DMSO-d₆) 14.885, 20.226, 30.766, 39.600,

43.160, 54.657, 56.410, 66.718, 121.074, 121.365,

126.453, 132.807, 138.681, 147.513, 158.840, 200.193.

EXAMPLE 28

Methyl trans-2-[3-(6-Trifluoromethylquin- azolin-4(3H)-on-3-yl)-2-oxopropyl]- 3-methoxypiperidine-1-carboxylate

By the method of Example 4 , 6-trifluoromethyl- quinazolin-4 (3H)-one and methyl trans-2- (3-bromo-2-oxo- propyl)-3-methoxypiperidine-1-carboxylate were converted into the title compound in 24% yield; m.p. 137-140° C.

¹H-NMR(CDCl₃) 1.4-1.9 (m, 4H), 2.9 (d, 2H), 3.3 (s, 3H),

3.5-3.9 (m, 4H), 3.7 (s, 3H), 5.2 (s, 2H), 7.7-8.7

(m, 4H). EXAMPLE 29

Methyl trans-2-[3-(6-Trifluoromethylquin- azolm-4(3H)-on-3-yl)-2-oxopropyl]- 3-hydroxypiperidine-1-carboxylate A 35 ml single neck round bottom flask equipped with a magnetic stirring bar was flame dried and then stoppered with a serum cap. Through a syringe needle the flask was evacuated and filled with dry nitrogen four times. A solution of 0.35 g (0.0008 mol) of title product of the preceding Example and 10 ml of dichloromethane was injected into the reaction flask, and with stirring the temperature was lowered to -70° C. Again with a syringe 3.0 ml of 1.0M boron tribromide in dichloromethane was introduced into the reaction vessel. After 10 minutes the reaction temperature was allowed to rise to -10° C. and was held there for 150 minutes. The reaction mixture was then combined with 11 ml of saturated sodium bicarbonate. The aqueous phase was separated and extracted three times with 5 ml portions of dichloromethane. The extracts were combined with the original organic layer, dried over anhydrous magnesium sulfate, and evaporated under reduced pressure to furnish the present. title compound: yield 0.34 g, 100%; ¹H-NMR(CDCl₃) 1.4-1.9 (m, 4H), 2.9 (d, 2H), 3.5-3.9 (m, 4H), 3.7 (s, 3H), 5.2 (s, 2H), 7.7- 8.7 (m, 4H).

EXAMPLE 30

trans-6-Trifluoromethyl-3-[3-(3-hydroxy- piperid-2-yl)-2-oxopropyl]quinazolin- 4(3H)-one Dihydrobromide

In a 15 ml single-neck round bottom flask equipped with a reflux condenser, a solution of 0.27 g (0.0006 mol) of title product of the preceding Example and 7 ml of 48% aqueous hydrobromic acid was immersed in an oil bath pre-heated to 150° C. Heating was continued for three minutes. The solution was allowed to cool to room temperature, and the volatile components were evaporated under reduced pressure. Ethanol (5 ml) was added to the residue, and again the mixture was evaporated to dryness. This operation was repeated once more to afford a dark residue which was then taken up in 3 ml of ethanol, heated at reflux briefly, and cooled to precipitate title product, 0.13 g (39%), m.p. 185-190° C.

EXAMPLE 31

Allyl trans-2-[3-(6-Cyanoquinazolin- 4(3H)-on-3-yl)-2-oxopropyl]-3-methoxy- piperidine-1-carboxylate

By the method of Example 4, 6-cyanoquinazolin-

4(3H)-one and allyl trans-2-(3-bromo-2-oxopropyl)-

3-methoxypiperidine-1-carboxylate were converted to title compound in 49% yield; ¹H-NMR(CDCl₃) 1.2-1.9

(m, 4H), 2.9 (d, 2H), 2.9-3.5 (m, 4H), 4.6-6.2 (m,

5H), 5.2 (s, 2H), 7.8-8.6 (m, 4H).

EXAMPLE 32

Allyl trans-2-[3-(6-Cyanoquinazolin- 4(3H)-on-3-yl)-2-oxopropyl]-3-hydroxy- piperidine-1-carboxylate

By the method of Example 20, title product of the preceding Example was converted to instant title product in 94% yield; ¹H-NMR(DMSO-d₆) 1.2-1.9 (m, 4H),

2.9-3.8 (m, 6H), 4.5-6.2 (m, 5H), 5.1 (s, 2H), 7.8-

8.6 (m, 4H).

EXAMPLE 33

trans-6-Cyano-3-[3-(3-acetoxypiperid-

2-yl)-2-oxopropyl]quinazolin- 4(3H)-one Dihydrobromide

1.34 g (0.0032 mol) of title product of the preceding Example was dissolved in 50 ml of 33% hydrobromic acid in glacial acetic acid at 0° C. and stirred for 30 minutes. The reaction mixture was poured into 750 ml of ether, and the resulting precipitate triturated several additional times with ether, and once with cold acetonitrile to give 880 mg of crude product, m.p. 226-228°. This was recrystallized from ethanol to afford 535 mg (32%) of the title compound, m.p. 227- 229° C.

EXAMPLE 34

trans-6-Cyano-3-[3-(3-hydroxypiperid-

2-yl)-2-oxopropyl]quinazolin- 4(3H)-one Dihydrochloride

Title product of the preceding Example, 0.25 g (0.00047 mol) was dissolved in 10.0 ml of 6N hydrochloric acid and allowed to stir at room temperature for 5 hours or until starting material is no longer detected by thin layer chromatography. The solvent was then removed at 26-28° C. under vacuum and the resulting crude solid triturated with acetone to give 179 mg (96%) of the title compound, m.p. 229-230° C. Analysis calculated for C₁₇H₁₈N₄N₄O₃•2HCl.1.5H₂O:

C, 47.90; H, 5.44; N, 13.14%. Found: C, 48.00; H, 5.15; N, 12.87%.

PREPARATION 1

4-Chloro-5-(4-chlorophenoxy)-2-nitrobenzoic Acid

To 30 ml of dry diglyme under a nitrogen atmosphere was added 0.960 g (0.02 mol) of sodium hydride disper- sion in mineral oil (50%). The solution was cooled to 10° C. and 1.28 g (0.01M) 4-chlorophenol in 15 ml of dry diglyme was added dropwise while maintaining the temperature at 10° C. This was followed by the dropwise addition of 2.36 g (0.01 mol) of 4,5-dichloro-2-nitro- benzoic acid in 15 ml of dry diglyme. The reaction mixture was then heated to 153° C. (oil bath) for 1 hour and 45 minutes. The reaction mixture was cooled to room temperature and poured into an ice/water mixture. The pH was then adjusted to 1.5 with 6N hydrochloric acid. The solution was extracted with ethyl acetate, and the organic layer dried over anhydrous magnesium sulfate. The solvent was removed and the crude solid triturated with hexane, followed by recrystallization from carbon tetrachloride to give the title compound: yield 1.65 g (50%) m.p. 160-162° C.

By the same method, the following other 2-nitro- benzoic acids were prepared from the appropriate Y¹ substituted phenol and 5-X¹ substituted 2-nitrobenzoic acid:

PREPARATION 2

2-Amino-4-chloro-5-(4-chlorophenoxy)benzoic Acid

A solution of title product of the preceding

Preparation (4.14 g, 0.013 mol) in 100 ml of ethanol was hydrogenated at 50 psig over Raney nickel (4.14 g, water moist). After one hour, the reaction mixture was filtered and the mother liquor evaporated under reduced pressure to give 3.37 g (90%) of the title compound, m.p. 160-170° C. This material was used in subsequent reactions without further purification.

By the same method, the other 2-nitrobenzoic acid derivatives of the preceding Preparation were converted ttoo 2--amino-4-(X¹ substituted)-5-(Y¹ substituted phenoxy)- benzoic acids as follows:

*¹ H-NMR(DMSO-d₆) shows multiplet at 6.7-7.8 ppm. PREPARATION 3

7-Chloro-6-(4-chlorophenoxy)quinazolin-4(3H)-one

[Formula (VI) with X¹=7-chloro and R¹=4-chlorophenoxy] A suspension of 3.3 g (0.011 mol) of title product of the preceding Preparation and 3.04 g (0.068 mol) of formamide was heated at 155° C. (oil bath). Within ten minutes the solid went into solution. After a total reaction time of 2 hours and 30 minutes, the solution was cooled and poured into water. The crude product was filtered and recrystallized from isopropyl alcohol. Yield 1.91 g (56%); m.p. 250-252° C.

By the same method other products of the preceding Preparation were converted to 7-(X¹ substituted)-6-(Y¹ substituted phenoxy)quinazolin-4(3H)-ones [of the formula (VI)] as follows:

PREPARATION 4

5-Bromo-2-methylaniline

A suspension of 300 g (1.39 mol) of 4-bromo-2- nitrotoluene 370 g (9.25 mol) of sodium hydroxide, and 4 liters of water was treated with 400 g (3.7 mol) of formamidine sulfinic acid. The mixture was heated under reflux overnight, and then steam distilled. When 16 liters of distillate had been collected, the distillation was stopped. The distillate was separated into aqueous and organic layers. The aqueous layer was extracted with ethyl acetate three times. The extracts were combined with the organic layer, dried over anhydrous sodium sulfate, filtered, and evaporated under reduced pressure to furnish the product as an oil:

b.p. 84° C. at 0.075 mmHg; yield 231.1 g (90%). This material has been prepared previously by reducing the nitro compound with iron [J. Frejka and F. Vymetal, Coll. Czech. Chem. Commun., 7, 436-443 (1935); C. A. 30, 1370 (1936)].

PREPARATION 5

N-(4-Bromo-2-methylphenyl)acetamide

With mechanical stirring and ice-bath cooling, a solution of 231 g (1.24 mol) of 5-bromo-2-methylaniline and 250 ml of diethyl ether was treated dropwise with 152.2 g (1.49 mol, 140 ml) of acetic anhydride at such a rate as to maintain the reaction temperature below 5° C. The product precipitated from the reaction mixture and was filtered to give colorless crystals: yield

215.2 g (76%); m.p. 160-161° C. [lit. m.p. 165° C.,

Frejka and Vymetal, loc, cit.]. PREPARATION 6

2-Acetylamino-4-bromobenzoic Acid With mechanical stirring, a suspension of 215 g (0.942 mol) of N-(4-bromo-2-methyl) acetamide in a solution of 310 g (1.257 mol) of magnesium sulfate heptahydrate, 447 g (2.83 mol) of potassium permanganat and 10 liters of water was heated under reflux for six hours during which time the mixture's color changed from clear purple to brownish-black. Heating was stopp and 50 ml of methanol was added. When at room temperature, the reaction mixture was treated with 250 g of diatomaceous earth and 100 g of activated carbon, and was filtered to give a clear colorless solution. The solution was adjusted to pH 4.4 by the addition of concentrated hydrochloric acid, and the product precipitat After filtering and drying the crystals, there was obtained 171.3 g (70%) of 2-acetylamino-4-bromobenzoic acid: m.p. 224-225° C. [lit. m.p. 220° C, Frejka and Vymetal, ioc. cit.].

PREPARATION 7

Ethyl 2-Amino-4-bromobenzoate

A solution of 119 g (0.461 mol) of 2-acetylamino- 4-bromobenzoic acid and 3 liters of absolute ethanol was cooled to 0° C. and was then saturated with a stream of dry hydrogen chloride gas. The solution was then heated under reflux for 24 hours. Upon cooling to room temperature, the solution was evaporated to about 750 ml and then poured into 2 liters of aqueous saturated sodium bicarbonate. The aqueous phase was extracted three times with 300 ml portions of chloroform. The combined extract were dried over anhydrous sodium sulfate, filtered, and evaporated to afford 23.8 g (21%) of ethyl 2-amino-4- bromobenzoate as an oil: ir (CHCl₃) 3504 cm, 3390, 1685, 1610, 1580 among others; ¹H-NMR(CDCl₃) 1.3 ppm (triplet, 3H, CH₂CH₃), 4.3 (quartet, 2H, CH₂CH₃), 5.8 (broad

singlet,2H, NH₂), 6.6 [doublet Tpart of AB pattern), 1H, aromatic H

], 6.8 (singlet, 1H, aromatic H), 7.7

[doublet (part of AB pattern), 1H, aromatic H].

PREPARATION 8

Ethyl 2-Amino-4-bromobenzoate Hydrochloride At room temperature, a solution of 3.09 g

(0.0127 mol) of ethyl 2-amino-4-bromobenzoate and 30 ml absolute ethanol was saturated with dry hydrogen

chloride gas. A colorless precipitate formed in the warm solution. When it was again at room temperature, the solution was diluted with 30 ml of diethyl ether; the resulting crystalline product was filtered and washed with diethyl ether. Thus there was obtained

2.72 g (77%) of the title compound: m.p. 147-150° C. Analysis calculated for C₉H₁₁BrClNO₂:

C, 38.53; H, 3.95; N, 4.99%. Found: C, 38.48; H; 4.02; N, 4.99%.

PREPARATION 9

Ethyl 2-Amino-4-bromo-5-thiocyanatobenzoate

In a 100 ml three-neck round bottom flask equipped with an internal thermometer and magnetic stirrer, a solution of 3.26 g (0.0116 mol) of ethyl 2-amino-4-bromo- benzoate hydrochloride, 2.12 g (0.0279 mol) of ammonium thiocyanate and 30 ml of acetic acid was cooled to 15° C. Bromine (1.86 g, 0.0116 mol) was then added dropwise with stirring. A precipitate formed. When the addition was complete, the solution was allowed to warm to room temperature, and to stir for an hour. The product was filtered, dried under nitrogen, and recrystallized from hexane and ethyl acetate to furnish crystalline ethyl 2-amino-4-bromo-5-thiocyanatobenzoate: yield 2.05 g (59%); m.p. 149-150° C.; ir (KBr) 3487 cm, 3453, 3375, 3346, 2980, 2146, 1697, 1614 among others; ¹H-NMR(CDCl₃) 1.4 ppm (triplet, 3H, CH₂CH₃), 4.3 (quartet, 2H, CH₂CH₃),

6.0 (broad singlet), 6.9 (sϊhglet, 1H, aromatic H)

78.1 (singlet, 1H aromatic H). PREPARATION 10

Ethyl 2-Amino-4-bromo-5-methylthiobenzoate Under a nitrogen atmosphere, with ice-bath cooling, and with magnetic stirring, 0.134 g (0.00585 mol) of sodium was dissolved in 20 ml of absolute ethanol.

Ethyl 2-amino-4-bromo-5-thiocyanatobenzoate (0.88 g, 0.00292 mol) was added, and when solution was almost complete, the mixture was treated with 0.498 g (0.22 ml, 0.0035 mol) of methyl iodide. The solution was allowed to warm to room temperature, and to stir overnight.

After pouring the reaction mixture into 200 ml of ice water, the resulting aqueous solution was adjusted to pH 6.5 by the addition of 2N hydrochloric acid. The aqueous solution was then extracted three times with 30 ml portions of ethyl acetate. The combined extracts were dried over anhydrous sodium sulfate, filtered, and evaporated to furnish the crude product: yield 0.88 g. This material was chromatographed under moderate pressure on a column of silica gel (i.d. 3.5 cm x height 17.5 cm); the eluant was 10% ethyl acetate/90% hexanes. Fractions of 20 ml each were collected. Fractions 27-38 gave crystals of the title compound: yield 0.66 g (78%);

m.p. 48-50° C.; ir(KBr) 3461 cm, 3354, 2976, 2914,

1680, 1603 among others; mass spectrum 289 (parent peak and molecular ion with expected isotope pattern),

274 (-15, -CH₃), 261 (-28 -CH₂CH₂), 243 (-46, -CH₃CH₂OH) among others; ¹H-NMR(CDCl₃) 1.3 ppm (triplet, 3H,

CH₂CH₃), 2.4 (singlet, 3H, SCH₃), 4.3 (quartet, 2H,

CH₂C

H₃), 5.8 (broad singlet, 2H, NH₂), 6.9 (singlet, 1

H

, aromatic H), 7.9 (singlet, 1H, aromatic H).

Analysis calculated for C₁₀H₁₂BrN0₂S:

C, 41.39; H, 4.17; N, 4.83%.

Found: C, 41.44; H, 4.14; N, 4.54%. PREPARATION 11

7-Bromo-6-methylthioquinazolin- 4(3H)-one Formic Acid Salt

In a flame dried 50 ml round bottom flask equipped with a magnetic stirrer and under a nitrogen atmosphere, a solution of 1.01 g (0.62 ml, 0.00659 mol) of phosphorous oxychloride and 5 ml of dry dimethylformamide was cooled to 0° C. In another 5 ml of dimethylformamide, 1.6 g

(0.00552 mol) of ethyl 2-amino-4-bromo-5-methylthio- benzoate was added to the reaction flask. The solution was stirred for an hour at 0° C., and then 11 ml of concentrated ammonium hydroxide was added. The reaction mixture was allowed to come to room temperature, and was stirred overnight. After being poured into 30 ml of water, the reaction mixture was filtered, and the product was dried under nitrogen. It was then recrystallized from hot formic acid to furnish colorless crystals of the title compound: yield 1.33 g (76%); m.p. 272- 274° C.; mass spectrum 270 (parent peak and molecular ion with expected isotope pattern), 255 (-15, -CH₃) among others.

Analysis calculated for C₁₀H₉BrN₂O₃S:

C, 37.87; H, 2.86; N, 8.83%.

Found: C, 38.06; H, 2.97; N, 8.79%.

PREPARATION 12

Ethyl 2-Amino-4-bromo-5-ethylthiobenzoate

In the manner of Preparation 10, 2.5 g (0.0083 mol) of ethyl 2-amino-4-bromo-5-thiocyanatobenzoate and

1.55 g (0.010 mol) of ethyl iodide were converted into the title compound: yield 1.78 g (70%); ir (neat) 3472 cm^-1, 3360, 2971, 2921, 2863, 1691, 1604, 1569, 1542 among others; mass spectrum peaks m/e 305 (parent peak, higher isotope), 303 (molecular ion) among others;

1H-NMR(CDCl₃) 1.4 ppm ["quartet" (overlapping triplets,

6H, SCH₂ CH₃, OCH₂CH₃], 2.3 (quartet, 2H, SCH₂CH₃), 4.4

(quartet, 2H, OCH₂CH₃), 5.9 (broad singlet, 2H, NH₂),

7.0 (singlet, 1H, aromatic H), 8.0 (singlet, 1H,

aromatic H).

PREPARATION 13

7-Bromo-6-ethylthioquinazolin- 4(3H)-one Formic Acid Salt

In the manner of Preparation 11, 1.78 g (0.00585 mol) of ethyl 2-amino-4-bromo-5-ethylthiobenzoate was trans- formed into the title compound: yield 1.22 g (63%);

m.p. 272-273° C.; mass spectrum m/e 286 (parent peak),

284 (molecular ion), 269 (-15, -CH₃), 256 (-28, -CO),

177 (-28, -79, -CO, -Br) among others.

Analysis calculated for C₁₁H₁₁BrN₂O₃S:

C, 39.89; H, 3.35; Br, 24.13; N, 8.46; S, 9.68%.

Found: C, 39.60; H, 3.20; Br, 25.40; N, 8.61; S, 9.94%.

PREPARATION 14

N-(4-Fluoro-2-methylphenyl)acetamide In the manner of Preparation 5, 20 g (0.160 mol) of 5-fluoro-2-methylaniline was converted into the title compound: yield 25.0 g (94%); m.p. 131-132° C., [lit. m.p. 133.5-134° C.: E. A. Steck, L. T. Fletcher, J. Am. Chem. Soc. 70, 439-440 (1948)].

PREPARATION 15

2-Acetylamino-4-fluorobenzoic Acid

In the manner of Preparation 6, 12.5 g (0.075 mol) of N-(4-fluoro-2-methylphenyl) acetamide was transformed into the title compound: yield 11.88 g (81%); m.p.

212.5-214.5° C., [lit. m.p. 209-209.5° C.: Steck and Fletcher loc. cit.].

PREPARATION 16

Ethyl 2-Amino-4-fluorobenzoate

In the manner of Preparation 7, 30.79 g (0.156 mol) of 2-acetylamino-4-fluorobenzoic acid was converted into the title compound: yield 20.43 g (71%); ir (neat) 3482 cm, 3367, 2933, 2903, 2871, 1692, 1627, 1593, 1573, 1500; ¹H-NMR(CDCl₃) 1.3 ppm (triplet, 3H, OCH₂CH₃), 4.3

(quartet, 2H, OCH₂CH₃), 5.8 (broad singlet, 2H, NH₂),

6.2-6.6 (multiplet, 2H, aromatic H), 7.2-8.0 (mul

tiplet, 1H, aromatic H).

PREPARATION 17

Ethyl 2-Amino-4-fluorobenzoate Hydrochloride

In the manner of Preparation 8, 20.43 g (0.112 mol) of ethyl 2-amino-4-fluorobenzoate was transformed into its hydrochloride salt: yield 19.35 g (79%); licorice odor; m.p. 153-156° C.; mass spectrum m/e 183 (molecular ion), 155 (-28, -CO), 138 (-45, -CH₃CH₂O), 137 (parent peak, -46, -CH₃CH₂OH), 110 (-73, -CO₂CH₂CH₃) among others; 1H-NMR(DMSO-d₆ ) 1.3 ppm (triplet, 3H, OCH₂CH₃), 4.2

(quartet, 2H, OCH₂CH₃), 6.3 (doublet of tripTets, 1H, aromatic H), 6.6

(doublet of doublets, 1H, aromatic H), 7.8 (doublet of doublets, 1H, aromatic H), 8.2 (broad singlet, 2H, NH₂).

Analysis calcu

lated for C₉H₁₁ClFNO₂ :

C, 49.21; H, 5.05; Cl, 16.14; F, 8.65; N, 6.38%.

Found: C, 49.45; H, 4.89; Cl, 15.77; F, 8.63; N, 6.39%.

PREPARATION 18

Ethyl 2-Amino-4-fluoro-5-thiocyanatobenzoate

In the manner of Preparation 9, 15.22 g (0.0695 mol) of ethyl 2-amino-4-fluorobenzoate hydrochloride was used to prepare the title compound. The yield after "flash" chromatography (on silica gel; eluant hexanes:chloroform 6:4) was 2.36 g (14%): m.p. 144-145° C.; ir (KBr) cm^-1 3453, 3341, 2979, 2932, 2899, 2141, 1698, 1625, 1591, 1552 among others; mass spectrum m/e 240 (molecular

ion), 212 (-28, -CO), 194 (parent peak, -46, -CH₃CH₂OH) among others.

Analysis calculated for C₁₀H₉FN₂O₂S:

C, 50.00; H, 3.75; N, 11.67; S, 13.33%. Found: C, 49.79; H, 3.78; N, 11.25; S, 13.09%. PREPARATION 19

Ethyl 2-Amino-4-fluoro-5-methylthiobenzoate In the manner of Preparation 10, 2.34 g (0.0097 mol) of ethyl 2-amino-4-fluoro-5-thiocyanatobenzoate was transformed into the title compound: yield 2.46 g (100%, some solvent included); ir(KBr) 3481 cm, 3367, 2980, 2917, 1688, 1620, 1582, 1556 among others; mass spectrum m/e 229 (molecular ion), 214 (-15, -CH-), 201 (-28, -CO), 183 (parent peak, -46, -CH₃CH₂OH) among others; ¹H-NMR(CDCl₃) 1.3 ppm (triplet, 3H, OCH₂CH₃),

2.3 (singlet, 3H, SCH₃), 4.2 (quartet, 2H, OCH₂CH₃),

6.0 (broad singlet, 2H, NH₂), 6.3 (doublet, 1H, aromatic

H), 7.9 (doublet, 1H, aromatic H).

PREPARATION 20

7-Fluoro-6-methylthioquinazolin-

4(3H)-one Formic Acid Salt

In the manner of Preparation 11, 2.46 g (0.0107 mol) of ethyl 2-amino-4-fluoro-5-methylthiobenzoate was converted into the title compound: yield 0.83 g (30%); mass spectrum m/e 210 (molecular ion and parent peak),

195 (-15, -CH ₃) among others; ¹H -NMR(DMSO-d₆) 2.6 ppm

(singlet, 3H, SCH₃ ), 7.4 (doublet, 1H, aromatic H), 7.9

(doublet, 1H, aromatic H), 8.0 (singlet, 1H, N=CH-N),

8.1 (singlet, 1H, HCO₂H).

Analysis calculated for C₁₀H₉FN₂O₃S:

C, 46.87; H, 3.54; N, 10.93; S, 12.51%. Found: C, 47.58; H, 3.38; N, 11.45; S, 13.67%. PREPARATIQN 21

N-(4-Iodo-2-methylphenyl)acetamide In the manner of Preparation 5, 10 g (0.043 mol) of 5-iodo-2-methylaniline was converted into the title compound: yield 11.1 g (94%); m.p. 182-183° C.

Analysis calculated for C₉H₁₀INO:

C, 39.29; H, 3.66; N, 5.09%. Found: C, 39.61; H, 3.77; N, 4.96%.

PREPARATION 22

2-Acetylamino-4-iodobenzoic Acid

In the manner of Preparation 6, 10 g (0.036 mol) of N-(4-iodo-2-methylphenyl) acetamide was transformed into the title compound: yield 4.66 g (42%); m.p. 229- 232° C.

Analysis calculated for C₉H₈INO₃:

C, 35.43; H, 2.64; I, 41.60, N, 4.59%. Found: C, 35.28; H, 2.66; I, 41.19; N, 4.51%.

PREPARATION 23

Ethyl 2-Amino-4-iodobenzoate

In the manner of Preparation 7, 31.22 g (0.102 mol) of 2-acetylamino-4-iodobenzoic acid was converted into the title compound: yield 17.65 g (59%); m.p. 51- 53° C.; ir (neat) 3475 cm, 3363, 2974, 2927, 2896, 1689, 1603, 1578, 1543; mass spectrum m/e 291 (molecular ion and parent peak), 245 (-46, -CH₃CH₂OH) among others; ¹H-NMR(CDCl₃) 1.3 ppm (triplet, 3H, OCH₂CH₃), 4.3

(quartet, 2H, OCH₂CH₃), 5.7 (broad singlet, 2H, NH₂), 6.9 (doublet, 1H

, aromatic H), 7.0 (singlet, 1H,

aromatic H), 7.5 (doublet, 1H, aromatic H).

Analysis calculated for C₉H₁₀INO₂:

C, 37.13; H, 3.46; I, 43.60; N, 4.81%. Found: C, 36.83; H, 3.35; I, 43.12; N, 5.52%. PREPARATION 24

Ethyl 2-Amino-4-iodobenzoate Hydrochloride In the manner of Preparation 8, 18.75 g (0.0644 mol) of ethyl 2-amino-4-iodobenzoate was transformed into its hydrochloride salt: yield 19.20 g (91%);

m.p. 147-149° C.; mass spectrum m/e 291 (molecular ion and parent peak), 245 (-46, -CH₃CH₂OH) among others; 1H-NMR(DMSO-d₆) 1.3 ppm (triplet, 3H, OCH₂CH₃), 4.2

(quartet, 2H, OCH₂CH₃), 6.9 (doublet of doublets, 1H,

aromatic H), 7.3 (doublet, 1H, aromatic H), 7.4

(doublet, 1H, aromatic H), 7.8 (broad singlet, 2H, NH₂).

Analysis calculated for C₉H₁₁ClINO₂:

C, 33.00; H, 3.39; I, 38.74; N, 4.28%. Found: C, 33.01; H, 3.36; I, 37.36; N, 4.24%.

PREPARATION 25

Ethyl 2-Amino-4-iodo-5-thiocyanatobenzoate

In the manner of Preparation 9, 17.05 g (0.052 mol) of ethyl 2-amino-4-iodobenzoate hydrochloride was used to prepare the title compound. The yield after flash chromatography (on silica gel; eluant hexanes:

chloroform 6:4) was 10.3 g (57%): m.p. 164-165.5° C.; ir (KBr) cm^-1 3449, 3345, 2966, 2920, 2142, 1693, 1613, 1566, 1534 among others; mass spectrum m/e 348

(molecular ion and parent peak), 320 (-28, -CO), 302 (-46, -CH₃CH₂OH) among others; ¹H-NMR(CDCl₃) 1.3 ppm (triplet, 3H, OCH₂CH₃), 4.2 (quartet, 2H, OCH₂CH₃),

5.8 (broad singlet, 2H , NH₂) , 7 . 2 ( singlet, 1H , aromatic

H) , 8 . 2 (singlet, 1H, aromatic H).

Analysis calculated for C₁₀H₉IN₂O₂S:

C, 34.50; H, 2.61; I, 36.45; N, 8.05; S, 9.21%.

Found: C, 33.94; H, 2.54; I, 35.20; N, 7.74; S, 10.54%. PREPARATION 26

Ethyl 2-Amino-4-iodo-5-(methylthio)benzoate In the manner of Preparation 10, 3.0 g (0.0086 mol) of ethyl 2-amino-4-iodo-5-thiocyanatobenzoate was transformed into the title compound: yield 1.79 g (62%);

m.p. 59-60° C.; ir(KBr) 3414 cm, 3311, 2980, 2906, 1690, 1607, 1568, 1549 among others; mass spectrum m/e 337 (molecular ion and parent peak), 322 (-15, -CH₃), 309 (-28, -CO), 291 (-46, -CH₃CH₂OH) among others; ¹H-NMR (CDCl₃) 1.4 ppm (triplet, 3H, OCH₂CH₃), 2.4 (singlet, 3H, SCH

3), 4.3 (quartet, 2H, OCH₂CH₃), 5.7 (broad singlet, 2H,

NH₂), 7.2 (singlet, 1H, aromatic H), 7.8 (singlet,

1H, aromatic H).

Analysis calculated for C₁₀H₁₂INO₂S:

C, 35.61; H, 3.56; N, 4.15%.

Found: C, 35.80; H, 3.63; N, 4.08%.

PREPARATION 27

7-Iodo-6-methylthioquinazolin- 4(3H)-one Formic Acid Salt

in the manner of Preparation 11, 2.5 g (0.0074 mol) of ethyl 2-amino-4-iodo-5-methylthiobenzoate was converted into the title compound: yield 1.23 g (46%);

m.p. 268-270° C.; mass spectrum m/e 318 (molecular ion and parent peak) among others; ¹H-NMR(DMSO-d₆) 2.6 ppm (singlet, 3H, SCH₃), 7.6 (singlet, 1H, aromatic H), 8.0

(singlet, 1H, aromatic H), 8.05 Csinglet, 1H, N=CH-N), 8.1 (singlet, 1H,

HCO₂H).

Analysis calculated for C₁₀ H₉IN₂O₃S:

C, 32.97; H, 2.47; N, 7.69%.

Found: C, 33.14; H, 2.68; N, 7.81%. PREPARATION 28

6-Chloro-7-methylthioquinazolin-4(3H)-one

Under a nitrogen atmosphere in a flame dried flask equipped with a magnetic stirrer and a reflux condenser, a mixture of 1.00 g (0.00465 mol) of 6,7-dichloroquin- azolin-4(3H)-one and 18 ml of dimethylformamide was treated at room temperature with 0.56 g (0.012 mol) of 50% sodium hydride in mineral oil. Foaming began immediately and most of the solids dissolved. When the foaming had subsided, 1.8 ml (0.0176 mol) of 47% methyl mercaptan in dimethyl formamide was added to the stirred mixture. The mixture was heated at 120° C. for six hours. When the reaction mixture was again at room temperature, a small amount of insoluble matter was filtered, and was rinsed with a few .ml of dimethylformamide. The filtrate was washed three times with 10 ml portions of hexane. The filtrate was then poured into 300 ml of ice and water. By the addition of 2N hydrochloric acid, the aqueous solution was adjusted to pH 2. There formed a fine colorless precipitate which was filtered, washed with water, air dried and pressed on a clay plate to furnish the title compound: yield 0.97 g (92%); m.p.

292-295° C. (dec); mass spectrum m/e 226 (parent peak and molecular ion with expected isotope pattern), 193 (-33) among others; ¹H-NMR(DMSO-d₆) 2.6 ppm (singlet,

3H, SCH₃), 7.45 (singlet, 1H, aromatic H), 8.0 (singlet, 1H, aro

matic H), 8.15 (singlet, 1H, N=CH-N).

PREPARATION 29

2-Amino-5-(ethylthio)benzoic Acid

To a 500 ml flask fitted with a magnetic stirrer, dropping funnel and thermometer, and containing a solution of 12.7 g (0.192 mol) of 85% potassium

hydroxide in 300 ml of methanol was added in portions 10.0 g (0.0481 mol) of methyl 2-amino-5-thiocyanato- benzoate. The solution was cooled to 10° C. and a soltuion of 6.29 g (0.058 mol) ethylbromide in 50 ml of methanol was added over 10 minutes. This was followed by the addition of 8.0 g (0.048 mol) potassium iodide. After 2.5 hours, the reaction mixture was evaporated to a semi-solid under reduced pressure and treated with 300 ml of water. The aqueous solution was extracted with chloroform, and the organic layer dried over magnesium sulfate. The solution was filtered and evaporated to give 7.5 g (79%) of crude product. This material was recrystallized from hexane to give 3.01 g (32%) of the title compound, m.p. 97-100° C.

PREPARATION 30

2-Amino-5-(propylthio)benzoic Acid

To a solution containing 50 ml of water, 25 ml of methanol and 6 ml of 1N sodium hydroxide was added

0.88 g (0.0037 mol) of ethyl 2-amino-5-propylthio- benzoate. The reaction was heated at reflux for 1 hour, cooled to room temperature, concentrated to a white solid and treated with 200 ml of water. The solution was then acidified with 6N hydrochloric acid and the resulting white precipitate filtered and dried to afford 0.54 g (70%) of the title compound, m.p. 91-93° C. PREPARATION 31

2-Amino-5-(methylthio)benzoic Acid By the method of Preparation 2, 2-nitro-5-(methylthio) benzoic acid [Tilley et al., Org. Prep. Proced. 13, pp 189-196 (1984)] was converted to instant title product in 70% yield, m.p. 148-150° C.

PREPARATION 32

Other Thiocyanato-2-aminobenzoate Esters By the method of Preparations 9, 18 and 25, ethyl 2-aminobenzoate and appropriately 3- or 4-substituted ethyl 2-aminobenzoates were converted to the following ethyl 2-amino-5-thiocyanatobenzoates:

By the same method, methyl 2-aminobenzoate was converted to methyl 2-amino-5-thiocyanatobenzoate

(m.p. 110-112° C.)) in 69% yield.

By the same method, ethyl 2-amino-5-chlorobenzoate was converted to ethyl 2-amino-5-chloro-3-thiocyanato- benzoate (m.p. 128-130° C.) in 8% yield.

PREPARATION 33

Other Alkylthio-2-aminobenzoate

Esters and Related Compounds

By the method of Preparations 10, 19 and 26, substituting an equivalent amount of the appropriate alkyl, benzyl or picolyl halide for methyl iodide, the following ethyl 5-substituted-3- or 4-substituted-

2-aminobenzoates were prepared from the products of the preceding Example:

^{(a )}m /e. 239.0980 (molecular ion).

(b)

¹H-NMR(CDCl₃) 1.3 (t, 3H), 3.8 (s, 2H), 4.2 (q, 2H), 6.4 (d, 1H), 7.1 (m, 5H), 7.7 (d, 1H).

^(c)m/e 259/261 (chlorine isotope).

(d)

1H-NMR(CDCl₃) 1.4 (m, 8H), 2.8 (t, 2H), 4.2 (q, 2H),

6.8 (s, 1H), 8.0 (s, 1H). PREPARATION 33 (Cont.)

^(e)m/e 303/305 (molecular ion, chlorine isotope). (^{f )}m/e 245/247 (molecular ion, chlorine isotope). (^g)m/e 289/291 (molecular ion, bromine isotope). (^h) hydrolyzed in next step without characterization; over-all yield 35%.

( ⁱ⁾correctly analyses for C₁₁H₁₄O₂NSBr.

(^j) m/e 245.0366 (molecular ion).

PREPARATION 34

Other Alkylthio-2-aminobenzoic Acids

By the method of Preparation 30, appropriate products of the preceding Example were hydrolyzed to yield the following 3-substituted-5-substituted- 2-amino-benzoic acids:

^(a)yield over 2-steps

PREPARATION 35

Other Alkylthioquinazolin-4(3H)-ones

By the method of Preparation 3, 2-aminobenzoic acids of preceding Preparations 30, 31 and 35 were converted to the following substituted quinazolin-

4(3H)-ones:

PREPARATION 36

Other Substituted Quinazolin- 4(3H)-ones Formic Acid Salts

By the method of Preparations 11, 13, 20 and 27, appropriately substituted ethyl 2-aminobenzoates of Preparation 34 were converted to the following substituted quinazolin-4 (3H)-ones:

PREPARATION 37

4-Trifluoromethyl-N-pivaloylaniline To a solution of 6.87 g (0.043 mol) of 4-trifluoro- methylaniline in 110 ml of dichloromethane was added 5.25 ml (0.043 mol) of pivaloylchloride. After stirring for 1.5 hours, 190 ml of a saturated solution of aqueous sodium bicarbonate was added. The reaction proceeded an additional 2 hours and the organic layer was separated and dried over anhydrous magnesium sulfate. The solution was filtered and the solvent removed to give the title compound, yield 9.16 g (88%), m.p. 154-158° C.

PREPARATION 38

2-(N-Pivaloyl)-5-trifluoromethylbenzoic Acid

A solution of 25.0 g (0.102 mol) of 4-trifluoro- methyl-N-pivaloylaniline in 140 ml of dry tetrahydro- furan was cooled to 5° C. under a nitrogen atmosphere. This was followed by the dropwise addition of 110 ml (0.22 mol) of 2.0M n-butyllithium in hexane. The

addition was carried out over 2 hours while maintaining the temperature below 15° C. When the addition was complete, the temperature was raised to 20° C. and the reaction stirred for 7 hours. The solution was then cooled to -60° C. and dry carbon dioxide gas was

bubbled through the reaction at a rapid rate for 15 minutes, during which time the thick suspension was diluted with an additional 150 ml of dry tetrahydro- furan. After stirring for 16 hours, the reaction mixture was treated with 100 ml of saturated aqueous ammonium chloride. The reaction mixture was then concentrated to 150 ml and diluted with 1.0 liter of water. The pH was adjusted to 1.0 with hydrochloric acid, and the resulting solution extracted with ethyl acetate. The PREPARATION 38 (Cont.)

organic layer was dried over magnesium sulfate, filtered and evaporated under reduced pressure to afford the crude product. This was recrystallized from toluene to give 7.8 g (26%) of the title compound, m.p. 196- 198° C.

PREPARATION 39

Methyl 2-Amino-5-trifluoromethylbenzoate

A solution of 7.46 g (0.026 mol) of 2-(N-pivaloyl)- 5-trifluoromethylbenzoic acid in 300 ml of methanol was cooled to 5° C. and saturated with gaseous hydrochloric acid. The reaction mixture was then heated at reflux for 20 hours, and evaporated to a solid. The crude solid was dissolved in chloroform and washed with saturated aqueous sodium bicarbonate. The organic layer was dried and evaporated to a viscous oil, which was purified by silica gel chromatography (9:1 hexane:ethyl- acetate). The title compound was isolated as a white solid, m.p. 51-52° C.; yield 4.0 g (71%).

PREPARATION 40

6-Trifluoromethylquinazolin-4(3H)-one By the method of Preparation 11, title product of the preceding Preparation was converted to instant title product in 71% yield, m.p. 209-211° C.

Analysis calculated for C₉H₅N₂OF₃:

C, 50.47; H, 2.34, N, 13.08%. Found: C, 49.81; H, 2.28; N, 12.98%.

PREPARATION 41

6-Cyanoquinazolin-4(3H)-one

6-Aminoquinazolin-4(3H)-one was slurried in 300 ml of 5% hydrochloric acid and the reaction mixture was cooled to 5° C. A solution of 6.72 g (0.097 mol) of sodium nitrite in 30 ml of water was added dropwise over 2.5 hours while maintaining the reaction temperature below 10° C. The resulting diazonium salt was then added portionwise to a hot (86° C.) solution of 7.84 g (0.0876 mol) of copper cyanide and 11.0 g (0.224 mol) sodium cyanide in 60 ml of water. Evolution of nitrogen was evident throughout the addition. After stirring for 30 minutes, the reaction mixture was filtered, washed with water, and air-dired. The crude product

(9.1 g) was purified by silica gel chromatography to afford 3.89 g (26%) of the title compound; m.p. 294- 300° C.

Claims

1. A compound having the formula

or

wherein

X is fluoro, chloro, bromo or iodo substituted at the 6- or 7-position;

R is (C₁-C₄)alkylthio;

X¹ is hydrogen or fluoro, chloro, bromo, iodo or methoxy substituted either at the 7- or at the 8-position; and

R¹ is cyano, trifluoromethyl, (C₁ -C₄ ) alkylthio,

4-picolylthio, 3,5-dichlorophenoxy,

where Y¹ is hydrogen, fluoro, chloro, bromo or phenoxy; and Y² is chloro or bromo; with the proviso that Y ¹ is other than hydrogen when X¹ is other than hydrogen,

or a pharmaceutically-acceptable acid addition salt thereof.

2. A compound of claim 1 having the formula (I).

3. The compound of claim 2 wherein R is methylthio and X is 6-chloro.

4. The compound of claim 2 wherein R is methylthio and X is 7-chloro.

5. A compound of claim 1 having the formula (II).

6. A compound of claim 5 wherein R¹ is cyano.

7. The compound of claim 6 wherein X¹ is hydrogen.

8. A compound of claim 5 wherein R¹ is trifluoro- methyl.

9. The compound of claim 8 wherein X¹ is hydrogen.

10. A compound of claim 5 wherein R¹ is

(C₁-C₄)alkylthio.

11. A compound of claim 10 wherein X¹ is hydrogen.

12. The compound of claim 11 wherein R¹ is

methylthio.

13. The compound of claim 11 wherein R¹ is ethylthio,

14. The compound of claim 11 wherein R¹ is propylthio.

15. A compound of claim 10 wherein R¹ is methylthio,

16. The compound of claim 15 wherein X¹ is

7-chloro

17. The compound of claim 15 wherein X¹ is

7-bromo.

18 The compound of claim 15 wherein X¹ is

7-fluoro.

19. The compound of claim 15 wherein X¹ is hydrogen.

20. The compound of claim 15 wherein X¹ is 8-chloro.

21. A compound of claim 5 wherein R¹ is

22. The compound of claim 21 wherein X¹ is hydrogen and Y¹ is 4-chloro.

23. A compound of claim 21 wherein X¹ is

7-chloro.

24. The compound of claim 23 wherein Y¹ is 4-chloro

25. The compound of claim 23 wherein Y¹ is 4-bromo.

26. The compound of claim 23 wherein Y¹ is 4-fluoro

27. A compound of claim 5 wherein R¹ is

28. The compound of claim 27 wherein X¹ is

2

hydrogen and Y is 4-bromo.

29. The compound of claim 28 wherein X¹ is 7-chloro and Y² is 4-chloro.

30. A method of controlling or preventing

coccidiosis in poultry which comprises administering to said poultry an anticoccidially effective amount of a compound of claim 1 in drinking water or in nutritionally-balanced feed.

31. A method of controlling or preventing

coccidiosis in poultry which comprises administering to said poultry an anticoccidially effective amount of a compound of claim 2 in drinking water or in nutritionally-balanced feed.

32. A method of controlling or preventing

coccidiosis in poultry which comprises administering to said poultry an anticoccidially effective amount of a compound of claim 5 in drinking water or in nutritionally-balanced feed.

33. A method of controlling or preventing

coccidiosis in poultry which comprises administering to said poultry an anticoccidially effective amount of a compound of claim 6 in drinking water or in nutritionally-balanced feed.

34. A method of controlling or preventing

coccidiosis in poultry which comprises administering to said poultry an anticoccidially effective amount of a compound of claim 10 in drinking water or in nutritionally-balanced feed.

35. A method of controlling or preventing

coccidiosis in poultry which comprises administering to said poultry an anticoccidially effective amount of a compound of claim 21 in drinking water or in nutritionally-balanced feed.

36. A method of controlling or preventing

coccidiosis in poultry which comprises administering to said poultry an anticoccidially effective amount of a compound of claim 27 in drinking water or in nutritionally-balanced feed.

37. A compound having the formula

or

wherein

X is fluoro, chloro, bromo or iodo substituted at the 6- or 7-position;

R is (C₁-C₄)alkylthio;

X¹ is hydrogen or fluoro, chloro, bromo, iodo or methoxy substituted either at the 7- or at the 8-position;

R¹ is cyano, trifluoromethyl, (C₁-C₄)alkylthio,

4-picolylthio, 3,5-dichlorophenoxy,

where Y¹ is hydrogen, fluoro, chloro, bromo or phenoxy; and Y² is chloro or bromo; with the proviso that Y¹ is other than hydrogen when X is other than hydrogen;

R² is hydrogen, acetyl or (C₁-C₄) alkyl; and

R ³ is hydrogen or COOR⁴; where R⁴ is allyl or

(C₁-C₄) alkyl;

with the provisos that at least one of R² and R ³ is other than hydrogen, and that R ³ is hydrogen when R² is acetyl.

38. A compound having the formula

or

wherein

X is fluoro, chloro, bromo or iodo substituted at the 6- or 7-position;

R is (C₁-C₄)alkylthio;

X¹ is hydrogen or fluoro, chloro, bromo, iodo or methoxy substituted either at the 7- or at the 8-position; and R¹ is cyano, trifluoromethyl, (C₁-C₄)alkylthio, 4-picolylthio, 3,5-dichlorophenoxy,

where Y¹ is hydrogen, fluoro, chloro, bromo or phenoxy; and Y² is chloro or bromo; with the proviso that Y¹ is other than hydrogen when X¹ is other than hydrogen.

39. A process for preparing a compound of the formula

or

wherein

R is (C₁-C₄)alkylthio;

R⁵ and R⁶ are each independently (C₁-C₄) alkyl;

X is fluoro, chloro, bromo or iodo;

R⁷ is (C₁-C₄alkylthio, 4-picolylthιo or and

Y² is chloro or bromo; and

X³ is fluoro, chloro, bromo or iodo substituted at the 3- or 4-position;

which comprises:

(a) reaction of a compound of the formula

or

with at least 2 molar equivalents of NH₄SCN in the presence of substantially 1 molar equivalent of Br₂ in a reaction inert solvent comprising a (C₁-C₄) alkanoic acid;

(b) solvolyzing the resulting compound having the formula

or

with at least one equivalent of a strong base in a reaction inert solvent comprising water or a (C₁-C₄)- alkanol; and

(c) reacting the resulting thiophenoxide, having the formula

or

with a compound of the formula

R⁶X⁴

or

R⁷X⁴

wherein X⁴ is a nucleophilically displaceable group, in the same or another reaction inert solvent to form a compound of the formula (VII) or (VIII).

40. A process of claim 39 wherein X⁴ is iodo, and the nucleophile is an alkali metal (C₁-C₄) alkoxide.

41. A process of claim 40 wherein the nucleophile is sodium methoxide and the solvent for step (b) comprises methanol.