CA1246587A - Process for the preparation of isocyanates - Google Patents
Process for the preparation of isocyanatesInfo
- Publication number
- CA1246587A CA1246587A CA000476613A CA476613A CA1246587A CA 1246587 A CA1246587 A CA 1246587A CA 000476613 A CA000476613 A CA 000476613A CA 476613 A CA476613 A CA 476613A CA 1246587 A CA1246587 A CA 1246587A
- Authority
- CA
- Canada
- Prior art keywords
- halogeno
- alkyl
- phenyl
- alkoxycarbonyl
- alkylthio
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D273/00—Heterocyclic compounds containing rings having nitrogen and oxygen atoms as the only ring hetero atoms, not provided for by groups C07D261/00 - C07D271/00
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- A01N47/00—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom not being member of a ring and having no bond to a carbon or hydrogen atom, e.g. derivatives of carbonic acid
- A01N47/08—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom not being member of a ring and having no bond to a carbon or hydrogen atom, e.g. derivatives of carbonic acid the carbon atom having one or more single bonds to nitrogen atoms
- A01N47/28—Ureas or thioureas containing the groups >N—CO—N< or >N—CS—N<
- A01N47/36—Ureas or thioureas containing the groups >N—CO—N< or >N—CS—N< containing the group >N—CO—N< directly attached to at least one heterocyclic ring; Thio analogues thereof
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D271/00—Heterocyclic compounds containing five-membered rings having two nitrogen atoms and one oxygen atom as the only ring hetero atoms
- C07D271/02—Heterocyclic compounds containing five-membered rings having two nitrogen atoms and one oxygen atom as the only ring hetero atoms not condensed with other rings
- C07D271/08—1,2,5-Oxadiazoles; Hydrogenated 1,2,5-oxadiazoles
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Agronomy & Crop Science (AREA)
- Pest Control & Pesticides (AREA)
- Plant Pathology (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Dentistry (AREA)
- General Health & Medical Sciences (AREA)
- Wood Science & Technology (AREA)
- Zoology (AREA)
- Environmental Sciences (AREA)
- Heterocyclic Carbon Compounds Containing A Hetero Ring Having Nitrogen And Oxygen As The Only Ring Hetero Atoms (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Macromonomer-Based Addition Polymer (AREA)
Abstract
Abstract of the Disclosure The invention relates to a process for the preparation of a 3-iso-cyanato-1,2,5-oxadiazole of the formula in which R is an aromatic radical, comprising reacting phosgene with a compound of the formula in which R1 is hydrogen,
Description
The present invention relates to a new process for the preparation of new 3-isocyanato-1,2,5-oxadiazo(es by reacting 3-amino-1,2,5-oxadia~oles or appropriate N'-substituted 3-ureido-1,2,5-oxadia~oles wi~h phosgene at temperatures between 150 and Z10C. The 3-isocyanato-1,2,5-oxadiazoLes are useful ;ntermediate products in organic chemical syntheses in many fields, for example for the preparation o~ plant protection agents, medica-ments, dyestuffs, etc.
The preparation of a large number of isocyanates from the corresponding amines by reaction with phosgene ;s already known. It is also known that N-heterocyclic compounds with an isocyanate group in the ~-posit~on are unstable and tend to undergo spontaneous cycl;sation 15 react;ons (see Angew. Chem~ 80, 362 - 363 t1968)).
It has been found tha~ the new 3-isocyanato-1,2,5-oxad;azoles of the general formula I
R ~ NCO (I) in which R represents an opt;onally substituted aromat;c rad;cal, as defined below, are obtained when compounds o~ the general formula II
N~-R1 ~( (II) in which ~10~
R has the mean;ng g;ven 2~ and R1 represents hydrogen or the groups of the general formulae III or IV
-CONH ~R (III) Le A 22 942 -65~7 -CONHR (VI) in which b41~
R has the meaning given ~be~e and R denotes an optionally substituted aliphatic or arom-atic radical, as defined below, are reacted with phosgene at temperatures between 150 and 220C, in the presence of an organic diluent, and the resulting isocyan-ate of the general formula I is isolated by the customary methods and, if required, purified.
In view of the prior art, it was surprising, and could not be foreseen by a man skilled in the art, that it would be possible to obtain the compounds of the general formula I in good yield and high purity and in a simple manner by the process accord-ing to the invention. With a knowledge of the prior art, it would in fact have been expected that, under the reaction conditions to be used according to the invention, any isocyanates formed would to a substantial extent undergo decomposition or react further to give undesired products, this taking place in the course of the reaction (see Angew. Chem. 80, 362 - 363 (1968)). Under milder conditions (such as lower temperatures and with the addition of a base), the desired products are obtained only in unsatisfactory amounts.
The optionally substituted aromatic radicals R and R2 of the above formulae contain 6 or 10 carbon atoms in the aryl part. Optionally substituted phenyl or naphthyl, preferably phenyl, may be mentioned as examples.
The optionally substituted aliphatic radical R2 repres-ents optionally substituted straight-chain or branched alkyl having
The preparation of a large number of isocyanates from the corresponding amines by reaction with phosgene ;s already known. It is also known that N-heterocyclic compounds with an isocyanate group in the ~-posit~on are unstable and tend to undergo spontaneous cycl;sation 15 react;ons (see Angew. Chem~ 80, 362 - 363 t1968)).
It has been found tha~ the new 3-isocyanato-1,2,5-oxad;azoles of the general formula I
R ~ NCO (I) in which R represents an opt;onally substituted aromat;c rad;cal, as defined below, are obtained when compounds o~ the general formula II
N~-R1 ~( (II) in which ~10~
R has the mean;ng g;ven 2~ and R1 represents hydrogen or the groups of the general formulae III or IV
-CONH ~R (III) Le A 22 942 -65~7 -CONHR (VI) in which b41~
R has the meaning given ~be~e and R denotes an optionally substituted aliphatic or arom-atic radical, as defined below, are reacted with phosgene at temperatures between 150 and 220C, in the presence of an organic diluent, and the resulting isocyan-ate of the general formula I is isolated by the customary methods and, if required, purified.
In view of the prior art, it was surprising, and could not be foreseen by a man skilled in the art, that it would be possible to obtain the compounds of the general formula I in good yield and high purity and in a simple manner by the process accord-ing to the invention. With a knowledge of the prior art, it would in fact have been expected that, under the reaction conditions to be used according to the invention, any isocyanates formed would to a substantial extent undergo decomposition or react further to give undesired products, this taking place in the course of the reaction (see Angew. Chem. 80, 362 - 363 (1968)). Under milder conditions (such as lower temperatures and with the addition of a base), the desired products are obtained only in unsatisfactory amounts.
The optionally substituted aromatic radicals R and R2 of the above formulae contain 6 or 10 carbon atoms in the aryl part. Optionally substituted phenyl or naphthyl, preferably phenyl, may be mentioned as examples.
The optionally substituted aliphatic radical R2 repres-ents optionally substituted straight-chain or branched alkyl having
- 2 -5~37 1 to 12, preferably 1 to 8 and in particular 1 to 6, carbon atoms, and optionally substituted cycloalkyl having 3 to 8, in particular 5 or 6, carbon atoms. Methyl, ethyl, n- and i-propyl, n-, i-, s-and t-butyl and cyclopentyl and cyclohexyl may be mentioned as examples.
- 2a -The aromatic radicals R and R2 and the aliphatic radical R2 can carry one or more, preferably 1 to 5, in particular 1 to 3 and particularLy pre-Ferably 1 or 2, identical or different substituents~ Suitable substitu-ents are all substituents which do not react with phos-gene under the reaction conditions according to the in-vention.
The following may be listed as examples:
halogen, preferably fluorine, chlorine, bromine and ;od-ine, in particular fluorine, chlorine and bromine;~y~ having preferably 1 to 6, in particular 1 to 4, carbon atoms, such as methyl, ethyl, n- and i-propyl, n-;-, sec and tert.-butyl; ~ hav;ng preferably 1 ~o 6, in particular 1 to 4, carbon atoms, such as methoxy, ethoxy, n- and i-propoxy~ n-, i-, sec- and tert.-butoxy;
alkylthio having preferably 1 to 6, in particular 1 to 4, carbon atoms, such as methylthio, ethylthio, n- and i-propylthio, n-, i-, sec- and tert.-butylthio; C1-C4-alkoxy-C1-C4-alkylthio; cyano; nitro; halogenoalk~ lo-~ xy and ~ alky~ , each having preferably 1to 4, in particular 1 or 2 carbon atoms and preferably 1 to 5, in particular 1 to 3, halogen atoms, the halogen atoms being identical or different and preferably be;ng fluor-ine, chlorine and/or bromine, in particular fluorine and/
or chlorine, such as trifluoromethyl, trifLuoromethoxy, trifluoromethylthio, chlorotrifluoroethoxy, difluorotri-chloroethoxy, dichlorodifluoroethoxy, hexafluoro-n-pro-poxy, chlorodifluoromethoxy and chlorodifluoromethylthio;
optionally halogen-substituted C~-C4-alkylcarbonyl, C~-C4-alkoxycarbonyl, C1-C4-alkoxycarbonyl-C1-C2-alkyl and C1-C~,-alkoxycarbonyl-C1-C4-alkyLthio;
C -C4-alkylene which is optionally substituted for _1_ fluorine, chlorine and/or methyl and which is bonded to the phenyl ring via two oxygen atoms; and phenoxy and phenylthio~ ~here phenoxy and phenyl~h;o in turn can be substituted as in the case of the aromatic radicals Le A 22 942 ~2~5~37 R and R2~
R preferably represents phenyl ~hich can be sub-stituted by halogen, nitro, cyano, C1-C~-alkyl~ C1-C4-alkoxy, C1-C4-alkylthio, halogeno-C1-C4-alkyl, haLogeno-C1-C4-alkoxy, halogeno-C1-C4-alkylthio, haLogeno C1-C~-alkylrarbonyl, C1-C4-alkylcarbonyl, halogeno-C1-C4-alkoxycarbonyL, C1-C~-alkoxycarbonyl, c1-C~alkoxycar-bonyl-C1-C2-alkyl and/or C1 C4-aLkoxycarbonyl-C1-C4-aLkylth;o.
R particuLarly preferably represents phenyL which can be substituted by fluor;ne~ chLorine, bromine, cyano, nitro, methyL, ethyL, methoxy, ethoxy, methylthio, tri-fLuoromethyl, trifluoroMethoxy~ trifluoromethyLthio, methyLcarbonyl, methoxycarbonyl, ethoxycarbonyL, n-butoxy-carbonyL, tert.-butoxycarbonyL, methoxycarbonyLmethyL, ethoxycarbonylmethyl, methoxycarbonylmethylthio and/or ethoxycarbonylmethylthio.
R very particularly preferably represents phenyl ~hich can be substituted by fluorine, chlorine and/or bromine.
R1 preferably represents hydrogen, the group of the general formula III in ~hich R has the meaning given above as being preferred, or the group of the general formula IV in ~hich R2 denotes C1-C6-alkyl or phenyL.
R1 particularLy preferably represents hydrogen, the group of the general formuLa III in which R has the meaning g;ven above as being particularly preferred, or the group of the general formula IV in which R2 denotes C1-C4-alkyL or phenyl.
In the above definitions, unless stated otherwise, haLogen denotes fluorine, chLorine, bromine or iodine, preferably fLuorine, chLorine and bromine, in particular fluorine or chLorine.
If 3-amino-40phenyl-1,2,5-oxadiazole is used as a starting material (formula I, R = phenyl, R1 - H~, the course of the reaction can be represented by the foLLo~-Le A 22 942 :~4~i5~7 ing equation:
C6H5~1~N 2 COC12 ~NCO
If N-n-butyL-N'-(4-phenyl-1,2,5-oxacliazol-3-yl)-urea (formula I~ R = phenyl, R1 = the group of the for-mula IV in which R2 = n-butyl) is used as a starting material~ the course of the reacti~n can be represented by the following equation:
C6~5 ~CO
C6H5` ~ ~NH CO NH nC4Hg ~ \ ~ // ~ nC4H9-CNO
If N,N'-bis-(4-phenyl-1,2,5-oxadiazol-3-yl)-urea ~formuLa I, R1 = the group of the formula III in which R = phenyl) is used as a starting material, the course of the reaction can be represented by the following equation:
N ~, N IL~ " -4 HC1 ~' N
The 3-amino-1,2,5-oxadiazoles of the formula II
(R1 = H~ which are to be used as start;ng materials are known and/or can be prepared by methods and processes known from the literature (see J. Prakt. Chem. 315, 4, pages 791 - 795 (1973)).
Some of the oxadiazoles of the formula (II~ (R1 = a group of the formula lII) which are to be used as starting materials are known and/or obtainable by custom-ary methods. They can read;ly be prepared from, for ex-ample, the compounds of the formula II (R1 = H) by the reaction with phosgene at temperatures from 50 to 130C, Le A 22 942 " ~465~7 in an inert organic diluent, for example chLorobenzene.
The oxadiazoles of the formula II (R1 = a group of the formula IV) which are to be used as starting mate-rials are known or can be prepared by customary processes 5see J. Prakt. Chem. 315, 4, pages 791 - 793 (1973)).
AlL diluents customarily used for phosgenations ~an be employed as inert organic diluents. When the re-action is ~carried out in an open system, the diluents used are ~hose which have a boiling point in the range of the react;on temperature ~hich can be used according to the invention (150 to 220C) or ~hich have a ~oiling point above this reaction temperature. ExampLes of sui~able diluents are opt;onally halogenated aliphatic and aroma-tic hydrocarbons, such as naphthalene, or benzene which is substituted by alkyL and/or halogen, and naphthalene or tetrahydronaphthalene or benzonitrile. o-Dichloroben-zene is preferably used.
The process according to the invention is carried out in a temperature range from 150 to 220C. It is pre-ferably carried out at 160 to ~90C, particularly prefer-ably at 160 to 180C. In special cases, it is also pos-sibLe for the temperature to be above or beloh the stated temperatures.
Depending on the apparatus employed, the process according to the invention can be carried out under ele-vated pressure, for example in an autoclave, or under atmospheric pressure. In general, the reaction is car-ried out under atmospheric pressure.
To carry out the process according to the inven-tion, it ;s advantageous to employ at least 1 mol of phos-gene per mol of starting material of the formula II in which R1 = H or the group of the formula IV~ and at least 2 mol of phosgene per mol of starting ma~erial of the formula II in which R1 = a group of the formula III.
When the process is carried out in open systems, the phosgene is passed continuously into the reaction mixture, Le A 2? 942 _ 7 _ ~ 2 ~ ~5 8 7 so that in general an excess of phosgene is introduced.
In carrying out the process according to the in~
vent;on ;n open systems, the star~ing material of the for ~ula II is advantageously discolved or suspended in the diluent. Phosgene is passed in and the reaction mixture is brought to the desired reaction temperatures~ if appro-priate ~hiLe stirring. The phosgene is passed in for about 2 to 5 hours, while heating~ The optimum reaction t;me for the particular reaction can readily be determined in the customary manner. The diluent is then removed by distillation, and the crude product obtained is puriFied by distillation in vacuo.
The procedure in closed systems is carried out in a correspond;ng manner. In this case, the required amount of phosgene is added, under pressure, to the reaction mixture, before the latter is heated.
As already stated above, the new compounds of the general formula I constitute valuable intermediat~
products~ Surprisingly, the end products of the process according to the invention are stable compounds which can be stored and handled without problems.
The compounds of the general formula I can be reacted with, for example, amines of the general formula V
R3 - NH2 (V) in ~hich R3 represents an optionally substituted aromatic or heteroaroratic radical, to give substituted furazanes of the general formula VI
R~ ~HCoNHR3 tVI) ~ ~ N
3D in which R and R3 have the meanings given above.
To prepare the compounds of the general formula VI, for example, molar amounts of the compounds of the formulae I and V are reacted in dry toluene at temperatures of Le A 22 ~42 ~2g~58~
~ 8 --approx. ~0C, and the solvent is removed by distillation when the reaction is complete. The rompounds of the for-mula VI remain behind as a solid mass.
For example, the following compounds o~ the for-mula VI can be obtained in this manner:
Com- R R3 Melting pound point tC) _.__ _ ___ ___ ___ A1 Cl- ~ - ~ ~~ ~ -CF3 20B
~ o- ~ -CF3 The compounds of the formula VI have high acti-vities against insects and spider mites and can therefore be used as pest-combating agents in pLant protec~ion.
The acaricidal activity of the compounds of the formula VI can be demonstrated by the following example:
Development_nhib;t;on test w;th Tetranychus urticae (common spider mite) Solvent: 3 parts by we;ght of dimethylformamide Emulsifier: 1 part by ~eight of alkylarylpolyglycol ether To produce a suitable preparation of active com-pound, 1 part by ~eight of active compound is mixed with the stated amount of solven~ and the stated amoun~ of emuls;f;er, and the concentrate is diluted with water to the des;red concentrat;ons~
The leaves of the bean plant (Phaseolus vulgar;s) on which about 50 eggs of the common spider mite have been deposited are immersed ;n the active compound preparation of appropriate concentration. The total of destroyed eggs, larvae, nymphs and dormant stages of a generation, based on the number of eggs used, gives the destruction in X. 100% means that all of the animals have been destroyed;
OX means that none of the animaLs have been destroyed.
In this test~ for example, the compounds A1 and A2 Le A 22 942 _ 9 ~
showed a destruct;on of 100X after 12 days at an active compound concentrat;on of 0.02X.
The compounds of the formula VI can be formuLated as solid or liquid pest-combating agents in the customary manner by mixing w;th su;table carriers (for example ground minerals or silica), diluents ~For exampLe dime-thylformamide) and emuls;f;ers (for example dibutylnaph-thalenesulphonate or cslcium dodecylbenzenesulphonate).
Appl;cation of these agents cnto the plants to be trea-ted is carried out by dusting or spraying, if appropriateafter further dilution ~ith water.
The examples wh;ch follow are ;ntended to illus-trate the process according to the invention (all percent-ages are % by weight, unless stated otherwise).
Example 1 N~o A mixture of 293 9 ~1.82 mol) of 3-amino-4-phenyl-1,2,5-oxad;azole and 2 l of distilled o-dichlorobenzene ;s initially introduced ;nto a 4 l reaction vessel, and the stirred mixture is heated rapidly to 160C~ During th;s procedure, phosgene gas is passed in at above 60C
(approx. 100 g/h). At 160 - 165C, further phosgene is passed ;n for 90 minutes, the ;nit;ally clear solution becom;ng a suspension which is thick but stiLl readily stirrable. The mixture is then heated under reflux, and phosgene is passed in for 2.5 hours under reflu~, a clear solution being formed. The m;xture is freed from phos-gene by incip;ent distillation under atmospheric pressure, and then evaporated down in a vacuum from a water pump.
The concentrate is distilled and redistilled, an oil pump being used.
278 9 (82X of theory) of 3-isocyanato~4~phenyl-1,2,5-oxadiazole having a boiling po;nt of 85C/0.1 mbar Le A 22_942 -- ~2~i587 and a melting point of 53 - 54C are obtained by this procedure.
__ 2 NCO
Cl- ~ ~
A mixture of 3~0 9 (1.53 mol) of 3-amino 4-(4'-chlorophenyl)-1~2,5-oxadiazole and 2.6 l of distiLLed o-dichlorobenzene are initially introduced in~o a 4 l reac-tion vessel, and the stirred mixture is heated rapidLy to 175C (reflux). During this procedure, phosgene gas is passed in at above 60C (approx. 100 g/h~ The mix-ture becomes clear a~ about 80C, and also remains clear during the entire reaction. After phosgene has been passed in under reflux for S hours, the mixture is freed from phosgene by incip;ent distillation under atmospher;c pressure, and then evaporated down ;n the vacuum from a water pump. The concentrate is distilled in the vacuum from an oil pump.
327 9 (96% of theory) of 3-isocyanato-4-(4'-chlo-rophenyl)-1,2,5-oxadiazole having a boiling point of 87 - 88C/O.ûS mbar and a melting point of 66C are ob-tained by this procedure.
Examples 3 - 9 The follo~ing compounds of the formula VII are obtained by the procedure given in Examples 1 and 2:
~NCO (V I I ) Le A 22 942 ___ _ Example Z Melt;ng Bo;ling po;nt No. point ~C) b.p~/2 mbar (C)
- 2a -The aromatic radicals R and R2 and the aliphatic radical R2 can carry one or more, preferably 1 to 5, in particular 1 to 3 and particularLy pre-Ferably 1 or 2, identical or different substituents~ Suitable substitu-ents are all substituents which do not react with phos-gene under the reaction conditions according to the in-vention.
The following may be listed as examples:
halogen, preferably fluorine, chlorine, bromine and ;od-ine, in particular fluorine, chlorine and bromine;~y~ having preferably 1 to 6, in particular 1 to 4, carbon atoms, such as methyl, ethyl, n- and i-propyl, n-;-, sec and tert.-butyl; ~ hav;ng preferably 1 ~o 6, in particular 1 to 4, carbon atoms, such as methoxy, ethoxy, n- and i-propoxy~ n-, i-, sec- and tert.-butoxy;
alkylthio having preferably 1 to 6, in particular 1 to 4, carbon atoms, such as methylthio, ethylthio, n- and i-propylthio, n-, i-, sec- and tert.-butylthio; C1-C4-alkoxy-C1-C4-alkylthio; cyano; nitro; halogenoalk~ lo-~ xy and ~ alky~ , each having preferably 1to 4, in particular 1 or 2 carbon atoms and preferably 1 to 5, in particular 1 to 3, halogen atoms, the halogen atoms being identical or different and preferably be;ng fluor-ine, chlorine and/or bromine, in particular fluorine and/
or chlorine, such as trifluoromethyl, trifLuoromethoxy, trifluoromethylthio, chlorotrifluoroethoxy, difluorotri-chloroethoxy, dichlorodifluoroethoxy, hexafluoro-n-pro-poxy, chlorodifluoromethoxy and chlorodifluoromethylthio;
optionally halogen-substituted C~-C4-alkylcarbonyl, C~-C4-alkoxycarbonyl, C1-C4-alkoxycarbonyl-C1-C2-alkyl and C1-C~,-alkoxycarbonyl-C1-C4-alkyLthio;
C -C4-alkylene which is optionally substituted for _1_ fluorine, chlorine and/or methyl and which is bonded to the phenyl ring via two oxygen atoms; and phenoxy and phenylthio~ ~here phenoxy and phenyl~h;o in turn can be substituted as in the case of the aromatic radicals Le A 22 942 ~2~5~37 R and R2~
R preferably represents phenyl ~hich can be sub-stituted by halogen, nitro, cyano, C1-C~-alkyl~ C1-C4-alkoxy, C1-C4-alkylthio, halogeno-C1-C4-alkyl, haLogeno-C1-C4-alkoxy, halogeno-C1-C4-alkylthio, haLogeno C1-C~-alkylrarbonyl, C1-C4-alkylcarbonyl, halogeno-C1-C4-alkoxycarbonyL, C1-C~-alkoxycarbonyl, c1-C~alkoxycar-bonyl-C1-C2-alkyl and/or C1 C4-aLkoxycarbonyl-C1-C4-aLkylth;o.
R particuLarly preferably represents phenyL which can be substituted by fluor;ne~ chLorine, bromine, cyano, nitro, methyL, ethyL, methoxy, ethoxy, methylthio, tri-fLuoromethyl, trifluoroMethoxy~ trifluoromethyLthio, methyLcarbonyl, methoxycarbonyl, ethoxycarbonyL, n-butoxy-carbonyL, tert.-butoxycarbonyL, methoxycarbonyLmethyL, ethoxycarbonylmethyl, methoxycarbonylmethylthio and/or ethoxycarbonylmethylthio.
R very particularly preferably represents phenyl ~hich can be substituted by fluorine, chlorine and/or bromine.
R1 preferably represents hydrogen, the group of the general formula III in ~hich R has the meaning given above as being preferred, or the group of the general formula IV in ~hich R2 denotes C1-C6-alkyl or phenyL.
R1 particularLy preferably represents hydrogen, the group of the general formuLa III in which R has the meaning g;ven above as being particularly preferred, or the group of the general formula IV in which R2 denotes C1-C4-alkyL or phenyl.
In the above definitions, unless stated otherwise, haLogen denotes fluorine, chLorine, bromine or iodine, preferably fLuorine, chLorine and bromine, in particular fluorine or chLorine.
If 3-amino-40phenyl-1,2,5-oxadiazole is used as a starting material (formula I, R = phenyl, R1 - H~, the course of the reaction can be represented by the foLLo~-Le A 22 942 :~4~i5~7 ing equation:
C6H5~1~N 2 COC12 ~NCO
If N-n-butyL-N'-(4-phenyl-1,2,5-oxacliazol-3-yl)-urea (formula I~ R = phenyl, R1 = the group of the for-mula IV in which R2 = n-butyl) is used as a starting material~ the course of the reacti~n can be represented by the following equation:
C6~5 ~CO
C6H5` ~ ~NH CO NH nC4Hg ~ \ ~ // ~ nC4H9-CNO
If N,N'-bis-(4-phenyl-1,2,5-oxadiazol-3-yl)-urea ~formuLa I, R1 = the group of the formula III in which R = phenyl) is used as a starting material, the course of the reaction can be represented by the following equation:
N ~, N IL~ " -4 HC1 ~' N
The 3-amino-1,2,5-oxadiazoles of the formula II
(R1 = H~ which are to be used as start;ng materials are known and/or can be prepared by methods and processes known from the literature (see J. Prakt. Chem. 315, 4, pages 791 - 795 (1973)).
Some of the oxadiazoles of the formula (II~ (R1 = a group of the formula lII) which are to be used as starting materials are known and/or obtainable by custom-ary methods. They can read;ly be prepared from, for ex-ample, the compounds of the formula II (R1 = H) by the reaction with phosgene at temperatures from 50 to 130C, Le A 22 942 " ~465~7 in an inert organic diluent, for example chLorobenzene.
The oxadiazoles of the formula II (R1 = a group of the formula IV) which are to be used as starting mate-rials are known or can be prepared by customary processes 5see J. Prakt. Chem. 315, 4, pages 791 - 793 (1973)).
AlL diluents customarily used for phosgenations ~an be employed as inert organic diluents. When the re-action is ~carried out in an open system, the diluents used are ~hose which have a boiling point in the range of the react;on temperature ~hich can be used according to the invention (150 to 220C) or ~hich have a ~oiling point above this reaction temperature. ExampLes of sui~able diluents are opt;onally halogenated aliphatic and aroma-tic hydrocarbons, such as naphthalene, or benzene which is substituted by alkyL and/or halogen, and naphthalene or tetrahydronaphthalene or benzonitrile. o-Dichloroben-zene is preferably used.
The process according to the invention is carried out in a temperature range from 150 to 220C. It is pre-ferably carried out at 160 to ~90C, particularly prefer-ably at 160 to 180C. In special cases, it is also pos-sibLe for the temperature to be above or beloh the stated temperatures.
Depending on the apparatus employed, the process according to the invention can be carried out under ele-vated pressure, for example in an autoclave, or under atmospheric pressure. In general, the reaction is car-ried out under atmospheric pressure.
To carry out the process according to the inven-tion, it ;s advantageous to employ at least 1 mol of phos-gene per mol of starting material of the formula II in which R1 = H or the group of the formula IV~ and at least 2 mol of phosgene per mol of starting ma~erial of the formula II in which R1 = a group of the formula III.
When the process is carried out in open systems, the phosgene is passed continuously into the reaction mixture, Le A 2? 942 _ 7 _ ~ 2 ~ ~5 8 7 so that in general an excess of phosgene is introduced.
In carrying out the process according to the in~
vent;on ;n open systems, the star~ing material of the for ~ula II is advantageously discolved or suspended in the diluent. Phosgene is passed in and the reaction mixture is brought to the desired reaction temperatures~ if appro-priate ~hiLe stirring. The phosgene is passed in for about 2 to 5 hours, while heating~ The optimum reaction t;me for the particular reaction can readily be determined in the customary manner. The diluent is then removed by distillation, and the crude product obtained is puriFied by distillation in vacuo.
The procedure in closed systems is carried out in a correspond;ng manner. In this case, the required amount of phosgene is added, under pressure, to the reaction mixture, before the latter is heated.
As already stated above, the new compounds of the general formula I constitute valuable intermediat~
products~ Surprisingly, the end products of the process according to the invention are stable compounds which can be stored and handled without problems.
The compounds of the general formula I can be reacted with, for example, amines of the general formula V
R3 - NH2 (V) in ~hich R3 represents an optionally substituted aromatic or heteroaroratic radical, to give substituted furazanes of the general formula VI
R~ ~HCoNHR3 tVI) ~ ~ N
3D in which R and R3 have the meanings given above.
To prepare the compounds of the general formula VI, for example, molar amounts of the compounds of the formulae I and V are reacted in dry toluene at temperatures of Le A 22 ~42 ~2g~58~
~ 8 --approx. ~0C, and the solvent is removed by distillation when the reaction is complete. The rompounds of the for-mula VI remain behind as a solid mass.
For example, the following compounds o~ the for-mula VI can be obtained in this manner:
Com- R R3 Melting pound point tC) _.__ _ ___ ___ ___ A1 Cl- ~ - ~ ~~ ~ -CF3 20B
~ o- ~ -CF3 The compounds of the formula VI have high acti-vities against insects and spider mites and can therefore be used as pest-combating agents in pLant protec~ion.
The acaricidal activity of the compounds of the formula VI can be demonstrated by the following example:
Development_nhib;t;on test w;th Tetranychus urticae (common spider mite) Solvent: 3 parts by we;ght of dimethylformamide Emulsifier: 1 part by ~eight of alkylarylpolyglycol ether To produce a suitable preparation of active com-pound, 1 part by ~eight of active compound is mixed with the stated amount of solven~ and the stated amoun~ of emuls;f;er, and the concentrate is diluted with water to the des;red concentrat;ons~
The leaves of the bean plant (Phaseolus vulgar;s) on which about 50 eggs of the common spider mite have been deposited are immersed ;n the active compound preparation of appropriate concentration. The total of destroyed eggs, larvae, nymphs and dormant stages of a generation, based on the number of eggs used, gives the destruction in X. 100% means that all of the animals have been destroyed;
OX means that none of the animaLs have been destroyed.
In this test~ for example, the compounds A1 and A2 Le A 22 942 _ 9 ~
showed a destruct;on of 100X after 12 days at an active compound concentrat;on of 0.02X.
The compounds of the formula VI can be formuLated as solid or liquid pest-combating agents in the customary manner by mixing w;th su;table carriers (for example ground minerals or silica), diluents ~For exampLe dime-thylformamide) and emuls;f;ers (for example dibutylnaph-thalenesulphonate or cslcium dodecylbenzenesulphonate).
Appl;cation of these agents cnto the plants to be trea-ted is carried out by dusting or spraying, if appropriateafter further dilution ~ith water.
The examples wh;ch follow are ;ntended to illus-trate the process according to the invention (all percent-ages are % by weight, unless stated otherwise).
Example 1 N~o A mixture of 293 9 ~1.82 mol) of 3-amino-4-phenyl-1,2,5-oxad;azole and 2 l of distilled o-dichlorobenzene ;s initially introduced ;nto a 4 l reaction vessel, and the stirred mixture is heated rapidly to 160C~ During th;s procedure, phosgene gas is passed in at above 60C
(approx. 100 g/h). At 160 - 165C, further phosgene is passed ;n for 90 minutes, the ;nit;ally clear solution becom;ng a suspension which is thick but stiLl readily stirrable. The mixture is then heated under reflux, and phosgene is passed in for 2.5 hours under reflu~, a clear solution being formed. The m;xture is freed from phos-gene by incip;ent distillation under atmospheric pressure, and then evaporated down in a vacuum from a water pump.
The concentrate is distilled and redistilled, an oil pump being used.
278 9 (82X of theory) of 3-isocyanato~4~phenyl-1,2,5-oxadiazole having a boiling po;nt of 85C/0.1 mbar Le A 22_942 -- ~2~i587 and a melting point of 53 - 54C are obtained by this procedure.
__ 2 NCO
Cl- ~ ~
A mixture of 3~0 9 (1.53 mol) of 3-amino 4-(4'-chlorophenyl)-1~2,5-oxadiazole and 2.6 l of distiLLed o-dichlorobenzene are initially introduced in~o a 4 l reac-tion vessel, and the stirred mixture is heated rapidLy to 175C (reflux). During this procedure, phosgene gas is passed in at above 60C (approx. 100 g/h~ The mix-ture becomes clear a~ about 80C, and also remains clear during the entire reaction. After phosgene has been passed in under reflux for S hours, the mixture is freed from phosgene by incip;ent distillation under atmospher;c pressure, and then evaporated down ;n the vacuum from a water pump. The concentrate is distilled in the vacuum from an oil pump.
327 9 (96% of theory) of 3-isocyanato-4-(4'-chlo-rophenyl)-1,2,5-oxadiazole having a boiling point of 87 - 88C/O.ûS mbar and a melting point of 66C are ob-tained by this procedure.
Examples 3 - 9 The follo~ing compounds of the formula VII are obtained by the procedure given in Examples 1 and 2:
~NCO (V I I ) Le A 22 942 ___ _ Example Z Melt;ng Bo;ling po;nt No. point ~C) b.p~/2 mbar (C)
3 2-C1 tO1-103 t3~ = 1,5646)*
4 2~Cl, 4-C1 67 1;25 6 4-Br 82 125 7 4-CH3 52105-~06 B 3-C1, 4-C1 40 132 (~ = 1,5378)*
1G *Refractive index Example 10 ~ ~ ~ NC0 A suspension of 140 9 (Q.4 mol) of N,N'-bis-(4-phenyl-1,2~5-oxadiazol-3-yl)-urea and 2 l of d;st;lled o-dichlorobenzene are initially introduced into a 4 l re-action vessel, and the stirred mixture ;s heated rap;dLy to 160C, and then to 175C treflux) ;n the course of 1 hour. During this procedure, phosgene gas is passed in at above 100C (approx. 100 g/h). Phosgene is then passed in for another hour, under reflux, the mixture slowly be;ng converted to a clear solution. The mixture Le A 22 942 ~4~
~ - 12 -is then freed from phosgene by incipient distiLlation under atmospheric pressure, after which it is evaporated down ;n the vacuum from a water pump. The concentrate is finally distilled in the vacuum from an oil pump.
After light ends t15.8 9 of dichlorobenzene and 7.2 9 of 3-isocyanato-4-phenyl-1,2,5-oxadiazoLe), 118 9 of 3-iso-cyanato-4-phenyl-1,2,5-oxadiazole are obtained as the principal fraction at a boiling point of 85G/0.1 mbar, in the form of a colourless product~
Total yield: 125 9 ~ 83% of theory~
Melting point of the product: 53 - 54C.
Example 10 a (starting material for Example 10) ~NH-CO-NH ~
A mixture of 161 9 ~1.0 mol) of 3-amino-4-phenyl-1,2,5-oxadiazole and 2 l of distilled chlorobenzene are initially introduced into a 4 l reaction vessel, and the stirred mixture is heated. Phosgene gas is passed into the mixture (approx. 100 g/h)~ A colourless finely divi-ded precipitate separates out above 60C. After 2 hours, a temperature of 130C (reflux) is reached. Phosgene is passed in under reflux for a further 30 minutes. The readily stirrable ~uspension formed is freed from phos-gene by ;ncipient distillation, and is then cooled and filtered: N,N'-bis-(4-phenyl-1,2,5-oxadiazol-3-yl)-urea is obtained in the form of 147 9 of virtually colourless crystals of melting point 280C. By evaporating down the filtrate, a further 21 9 of the product are obtained in the form of brownish crystals of melting point 280C.
The product can be purified by recrystall;sation from chlorobenzene. The colourless crystals ob~ained in this procedure have a melting point of 280 - 281C.
The remaining ureas which can be used as starting mater;als can be prepared similarly~
Le A 2? 942 ~ 13 -Example 11 N~o ~N
52 9 (0.2 mol) of N-n-butyl-N'-(4-phenyl-1,2,5-oxadiazol-3-yl)-urea (melting point 155C) are added to 400 mL of 0-dichLorobenzene~ and the mixture is heated under reflux. During this procedure, phosgene is passed in at a rate of approx. 100 g/h, until the urea has been com-pletely converted (clear solution). After the excess phosgene has been removed under reduced pressure, the solvent is dis-tilled off together ~ith the n-butyl isocyanate, and the residue is distilled in vacuo. 29 9 (77.4X of theory) of 3-isocyanato-4-phenyl-1,2,5-oxadiazole (melting point 53 -54C) were ob~ained at a boiling point of 82 -84C/2 mbar.
xample 12 ~ ~ C0 56 9 (0.21 mol) of N-phenyl-N'-(4-phenyl-1,2,5-oxadiazoL-3-yL)-urea (melting point 213C) in S00 ml of o-dichlorobenzene are heated under reflux. Phosgene is passed into the mixture at a rate of 1~0 g/h, until the urea has been completely converted ~clear solution). The excess phosgene is removed under slightly reduced pres-sure, and the solvent and the phenyl isocyanate formed are distilled off. In the subsequent distillation in vacuo, 24 9 (64.2X of theory) of 3-isocyanato-4-phenyl-1,2,5-oxadiazole (melting point 53 - 54C) are obtained.
The preparation of the insectidal and acaricidal compounds of the formula VI can be illustrated by the following example:
Le A 22 942 465~
Cl ~ ~ ,NH-C0-NH ~ 0 ~ CF3 (Compound A1) 2.53 9 (0.01 mol) of 4-t4-trifluoromethylphenoxy)-aniline are d;ssoLved in 60 ml of dry toLuene at 60C~
After 202 9 (0.01 moL) of 3-isocyanato-4-(4-chLorophenyl)-1,2,5-oxad;azoLe in 10 ml of dry toluene have been added, the mix~ure is stirred for 30 minutes at 80C and the bulk of the solvent is then distilled off. The residue is separated off, and the product is then dried.
3.6 9 (76% of theory) of N-~4~(4-trifluoromethyl-phenoxy)-phenyl~-N'-C4-(4-chlorophenyl)-1,2,5-oxadiazol-3-yl)-urea of melting point 208C are obtained.
The remaining compounds of the formula VI can be prepared according to this exampLe.
Le A 22 942 _____
1G *Refractive index Example 10 ~ ~ ~ NC0 A suspension of 140 9 (Q.4 mol) of N,N'-bis-(4-phenyl-1,2~5-oxadiazol-3-yl)-urea and 2 l of d;st;lled o-dichlorobenzene are initially introduced into a 4 l re-action vessel, and the stirred mixture ;s heated rap;dLy to 160C, and then to 175C treflux) ;n the course of 1 hour. During this procedure, phosgene gas is passed in at above 100C (approx. 100 g/h). Phosgene is then passed in for another hour, under reflux, the mixture slowly be;ng converted to a clear solution. The mixture Le A 22 942 ~4~
~ - 12 -is then freed from phosgene by incipient distiLlation under atmospheric pressure, after which it is evaporated down ;n the vacuum from a water pump. The concentrate is finally distilled in the vacuum from an oil pump.
After light ends t15.8 9 of dichlorobenzene and 7.2 9 of 3-isocyanato-4-phenyl-1,2,5-oxadiazoLe), 118 9 of 3-iso-cyanato-4-phenyl-1,2,5-oxadiazole are obtained as the principal fraction at a boiling point of 85G/0.1 mbar, in the form of a colourless product~
Total yield: 125 9 ~ 83% of theory~
Melting point of the product: 53 - 54C.
Example 10 a (starting material for Example 10) ~NH-CO-NH ~
A mixture of 161 9 ~1.0 mol) of 3-amino-4-phenyl-1,2,5-oxadiazole and 2 l of distilled chlorobenzene are initially introduced into a 4 l reaction vessel, and the stirred mixture is heated. Phosgene gas is passed into the mixture (approx. 100 g/h)~ A colourless finely divi-ded precipitate separates out above 60C. After 2 hours, a temperature of 130C (reflux) is reached. Phosgene is passed in under reflux for a further 30 minutes. The readily stirrable ~uspension formed is freed from phos-gene by ;ncipient distillation, and is then cooled and filtered: N,N'-bis-(4-phenyl-1,2,5-oxadiazol-3-yl)-urea is obtained in the form of 147 9 of virtually colourless crystals of melting point 280C. By evaporating down the filtrate, a further 21 9 of the product are obtained in the form of brownish crystals of melting point 280C.
The product can be purified by recrystall;sation from chlorobenzene. The colourless crystals ob~ained in this procedure have a melting point of 280 - 281C.
The remaining ureas which can be used as starting mater;als can be prepared similarly~
Le A 2? 942 ~ 13 -Example 11 N~o ~N
52 9 (0.2 mol) of N-n-butyl-N'-(4-phenyl-1,2,5-oxadiazol-3-yl)-urea (melting point 155C) are added to 400 mL of 0-dichLorobenzene~ and the mixture is heated under reflux. During this procedure, phosgene is passed in at a rate of approx. 100 g/h, until the urea has been com-pletely converted (clear solution). After the excess phosgene has been removed under reduced pressure, the solvent is dis-tilled off together ~ith the n-butyl isocyanate, and the residue is distilled in vacuo. 29 9 (77.4X of theory) of 3-isocyanato-4-phenyl-1,2,5-oxadiazole (melting point 53 -54C) were ob~ained at a boiling point of 82 -84C/2 mbar.
xample 12 ~ ~ C0 56 9 (0.21 mol) of N-phenyl-N'-(4-phenyl-1,2,5-oxadiazoL-3-yL)-urea (melting point 213C) in S00 ml of o-dichlorobenzene are heated under reflux. Phosgene is passed into the mixture at a rate of 1~0 g/h, until the urea has been completely converted ~clear solution). The excess phosgene is removed under slightly reduced pres-sure, and the solvent and the phenyl isocyanate formed are distilled off. In the subsequent distillation in vacuo, 24 9 (64.2X of theory) of 3-isocyanato-4-phenyl-1,2,5-oxadiazole (melting point 53 - 54C) are obtained.
The preparation of the insectidal and acaricidal compounds of the formula VI can be illustrated by the following example:
Le A 22 942 465~
Cl ~ ~ ,NH-C0-NH ~ 0 ~ CF3 (Compound A1) 2.53 9 (0.01 mol) of 4-t4-trifluoromethylphenoxy)-aniline are d;ssoLved in 60 ml of dry toLuene at 60C~
After 202 9 (0.01 moL) of 3-isocyanato-4-(4-chLorophenyl)-1,2,5-oxad;azoLe in 10 ml of dry toluene have been added, the mix~ure is stirred for 30 minutes at 80C and the bulk of the solvent is then distilled off. The residue is separated off, and the product is then dried.
3.6 9 (76% of theory) of N-~4~(4-trifluoromethyl-phenoxy)-phenyl~-N'-C4-(4-chlorophenyl)-1,2,5-oxadiazol-3-yl)-urea of melting point 208C are obtained.
The remaining compounds of the formula VI can be prepared according to this exampLe.
Le A 22 942 _____
Claims (10)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the preparation of a 3-isocyanato-1,2,5-oxadiazole of the formula in which R is C6-C10-aryl optionally substituted by halogen, nitro, cyano, C1-C6-alkyl, C1-C6-alkoxy, C1-C6-alkylthio, halogeno-C1-C4-alkyl, halogeno-C1-C4-alkoxy, halogeno-C1-C4-alkylthio, C1-C4-alkoxy-C1-C4-alkylthio, halogeno-C1-C4-alkylcarbonyl, C1-C4-alkoxycarbonyl, C1-C4-alkoxycarbonyl-C1-C2-alkyl, C1-C4-alkoxycarbonyl-C1-C4-alkylthio, C1-C4-alkylene (optionally substituted by fluorine, chlorine or methyl) bonded to the aryl group via two oxygen atoms, or phenoxy or phenylthio wherein the phenoxy or phenylthio can be once further substituted as defined for C6-C10-aryl herein, comprising reacting phosgene with a compound of the formula in which R1 is hydrogen, -CONHR2 , and R2 represents C1-C12-alkyl, C3-C8-cycloalkyl or C6-C10-aryl, in each case optionally substituted by halogen, nitro, cyano, C1-C6-alkyl, C1-C6-alkoxy, C1-C6-alkythio, halogeno-C1-C4-alkyl, halogeno-C1-C4-alkoxy, halogeno-C1-C4-alkylthio, C1-C4-alkoxy-C1-C4-alkylthio, halogeno-C1-C4-alkylcarbonyl, C1-C4,-alkoxycarbonyl, C1-C4-alkoxycarbonyl-C1-C2-alkyl, C1-C4-alkoxycarbonyl-C1-C4-allkyl-thio or, if R2 represents C6-Cl0-aryl, optionally substituted by C1-C4-alkylene (optionally substituted by fluorine, chlorine or methyl) bonded to the aryl group via two oxygen atoms, or phenoxy or phenylthio wherein the phenoxy or phenylthio can be once further substituted as defined for C6-Cl0-aryl herein at a temperature between about 150°C and 220°C in the presence of an organic diluent.
2. A process according to claim 1 wherein phenyl or phenyl substituted by halogen, nitro, cyano, C1-C4-alkyl, C1-C4-alkoxy, C1-C4-alkylthio, halogeno-C1-C4-alkyl, halogeno-C1-C4-alkoxy, halogeno-C1-C4-alkylthio, halogeno-C1-C4-alkylcarbonyl, C1-C4-alkylcarbonyl, halogeno-C1-C4-alkoxycarbonyl, C1-C4-alkoxycarbonyl, C1-C4-alkoxycarbonyl-C1-C2-alkyl or C1-C4-alkoxycarbonyl-C1-C4-alkylthio.
3. A process according to claim 1, in which R is phenyl or phenyl substituted by fluorine, chlorine, bromine, cyano, nitro, methyl, ethyl, methoxy, ethoxy, methylthio, trifluoromethyl, trifluoromethoxy, trifluoromethylthio, methyl-carbonyl, methoxycarbonyl, ethoxycarbonyl, n-butoxycarbonyl, tert.-butoxycarbonyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, methoxycarbonylmethylthio or ethoxycarbonyl-methylthio.
4. A process according to claim 1, in which R is phenyl or phenyl substituted by fluorine, chlorine and/or bromine.
5. A process according to claim 1, in which R2 is C1-C6-alkyl or phenyl.
6. A process according to claim 2, in which R2 is C1-C4-alkyl or phenyl.
7. A process according to claim 1, in which R1 is hydrogen, (4-phenyl-1,2,5-oxadiazol-3-yl)-carbam-oyl, or (4-chlorophenyl-1,2,5-oxadiazol-3-yl)-carbamoyl.
8. A process according to claim 1, in which R1 is hydrogen.
9. A process according to claim 1, wherein the reaction is carried out at a temperature between about 160 and 190°C.
10. A process according to claim 1, wherein the reaction is carried out at a temperature between about 160 and 180°C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3409887.9 | 1984-03-17 | ||
| DE19843409887 DE3409887A1 (en) | 1984-03-17 | 1984-03-17 | METHOD FOR PRODUCING ISOCYANATES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1246587A true CA1246587A (en) | 1988-12-13 |
Family
ID=6230837
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000476613A Expired CA1246587A (en) | 1984-03-17 | 1985-03-15 | Process for the preparation of isocyanates |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0156198B1 (en) |
| JP (1) | JPS60204773A (en) |
| KR (1) | KR920003896B1 (en) |
| AT (1) | ATE33646T1 (en) |
| CA (1) | CA1246587A (en) |
| DE (2) | DE3409887A1 (en) |
| DK (1) | DK120585A (en) |
| HU (1) | HU196975B (en) |
| IL (1) | IL74603A (en) |
| ZA (1) | ZA851958B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5405858A (en) * | 1992-03-19 | 1995-04-11 | Bayer Aktiengesellschaft | Furazanylureas |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3622862A1 (en) * | 1986-07-08 | 1988-01-21 | Bayer Ag | SUBSTITUTED FURAZANE |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1071629A (en) * | 1951-09-15 | 1954-09-02 | France Etat | Process for the preparation of isocyanates |
-
1984
- 1984-03-17 DE DE19843409887 patent/DE3409887A1/en not_active Withdrawn
-
1985
- 1985-03-05 AT AT85102444T patent/ATE33646T1/en not_active IP Right Cessation
- 1985-03-05 DE DE8585102444T patent/DE3562247D1/en not_active Expired
- 1985-03-05 EP EP85102444A patent/EP0156198B1/en not_active Expired
- 1985-03-13 JP JP60048447A patent/JPS60204773A/en active Granted
- 1985-03-14 IL IL74603A patent/IL74603A/en unknown
- 1985-03-15 KR KR1019850001670A patent/KR920003896B1/en not_active IP Right Cessation
- 1985-03-15 DK DK120585A patent/DK120585A/en not_active Application Discontinuation
- 1985-03-15 CA CA000476613A patent/CA1246587A/en not_active Expired
- 1985-03-15 HU HU85966A patent/HU196975B/en unknown
- 1985-03-15 ZA ZA851958A patent/ZA851958B/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5405858A (en) * | 1992-03-19 | 1995-04-11 | Bayer Aktiengesellschaft | Furazanylureas |
Also Published As
| Publication number | Publication date |
|---|---|
| HU196975B (en) | 1989-02-28 |
| IL74603A (en) | 1989-06-30 |
| KR920003896B1 (en) | 1992-05-18 |
| JPS60204773A (en) | 1985-10-16 |
| JPH0481991B2 (en) | 1992-12-25 |
| ATE33646T1 (en) | 1988-05-15 |
| ZA851958B (en) | 1985-11-27 |
| KR850006390A (en) | 1985-10-05 |
| HUT36810A (en) | 1985-10-28 |
| EP0156198A2 (en) | 1985-10-02 |
| DK120585D0 (en) | 1985-03-15 |
| IL74603A0 (en) | 1985-06-30 |
| EP0156198A3 (en) | 1986-05-07 |
| EP0156198B1 (en) | 1988-04-20 |
| DE3562247D1 (en) | 1988-05-26 |
| DK120585A (en) | 1985-09-18 |
| DE3409887A1 (en) | 1985-09-19 |
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