MXPA99010518A - Arylsubstituted piperazines useful in the treatement of benign prostatic hyperlasia - Google Patents

Abstract

This invention relates to a series of arylsubstituted piperazines, of Formula (I), pharmaceutical compositions containing them and intermediates used in their manufacture. The compounds of the invention selectively inhibit binding to the&agr;-1a adrenergic receptor, a receptor which has been implicated in benign prostatic hyperplasia. As such the compounds are potentially useful in the treatment of this and other disease.

Description

PIPERAZINES REPLACED WITH USEFUL ARILUS IN THE TREATMENT OF PROSTATIC HYPERPLASIA BENIGNA This invention relates to a series of aryl substituted piperazines, pharmaceutical compositions containing them and intermediates useful in their manufacture. The compounds of the invention selectively inhibit binding to the adrenergic receptor a-1a, which is a receptor that has been implicated in benign prostatic hyperplasia. In addition, the compounds of the invention reduce intraurethral pressure in a live model. As such the compounds are useful in the treatment of this disease.

BACKGROUND OF THE INVENTION Benign prostatic hyperplasia (BPH), a non-malignant enlargement of the prostate, is the most common benign tumor in men. Approximately 50% of all men over 65 have some degree of BPH and a third of these men have clinical symptoms consistent with obstruction of the bladder outlet (Hieble and Caine, 1986). In the United States, benign and malignant diseases of the prostate are responsible, more than diseases of any other organ, for most surgical interventions in men over 50 years of age.

There are two components of the BPH, a static component and a dynamic component. The static component is due to enlargement of the prostate, which can result in compression of the urethra and obstruction of the flow of urine from the bladder. The dynamic component is due to an increased tone of the smooth muscle of the neck of the bladder and of the prostate itself (which interferes with the emptying of the bladder) and is regulated by the alpha 1 adrenergic receptors (1-AR). The medical treatments available for BPH solve these components to varying degrees, and the therapeutic choices are further expanded. Surgical treatment options face the static component of BPH and include transurethral resection of the prostate (TURP), transurethral incision of the prostate (TUIP), open prostatectomy, balloon dilation, hyperthermia, endoprosthesis (stents) and removal with To be. TURP is the preferred treatment for patients with BPH and in the United States in 1990 approximately 320,000 TURP were performed with an estimated cost of $ 2,200 million dollars (Weis et al., 1993). Although it is an effective treatment for most men with symptomatic BPH, approximately 20-25% of patients do not have a satisfactory long-term outcome (Leport and Rigaud 1990). Complications include retrograde ejaculation (70-75% of patients), impotence (5-10%), postoperative urinary tract infection (5-10%) and some degree of urinary incontinence (2-4%) (Mebust et al. al., 1989). In addition, the reoperation rate is approximately 15-20% in men evaluated at 10 years or more (Wennberg et al., 1987). In addition to surgical methods, there are some drug therapies that confront the static component of this condition. The finasteride (Prosear®, Merck) is one such therapeutic agent that is indicated for the treatment of symptomatic BPH. This drug is a competitive inhibitor of the enzyme 5a-reductase which is responsible for the conversion of testosterone to dihydrotestosterone in the prostate gland (Gormley et al., 1992). It appears that dihydrotestosterone is the main mitogen for prostate growth, and agents that inhibit 5a-reductase reduce the size of the prostate and improve the flow of urine through the prostate urethra. Although the finasteride is a potent inhibitor of 5a-reductase and causes a marked decrease in serum and tissue concentrations of dihydrotestosterone, it is only moderately effective in treating symptomatic BPH (Oesteriing, 1995). The effects of the finasteride take 6-12 months to become evident and for many men the clinical improvement is minimal (Barry, 1997). The dynamic component of BPH has been addressed by the use of adrenergic receptor blocking agents (a1-AR blockers) which act by decreasing the smooth muscle tone within the prostate gland itself. A variety of a1-AR blockers (terazozine) have been investigated, prazosin, and doxazosin) for the treatment of symptomatic bladder obstruction due to BPH, with terazosin (Hytrin ", Abbott) being the most intensively studied.A1-AR blockers are well tolerated, approximately 10 -15% of patients develop a clinically adverse event (Lepor, 1995) .The undesired effects of all elements of this class are similar, postural hypotension being the most commonly experienced side effect (Leport et al., 1992). Compared with da-reductase inhibitors, 1-AR blocking agents have a faster onset of action (Steers, 1995), however, their therapeutic effect, as measured by improvements in symptom score and the maximum urinary flow rate is moderate (Oesteriing, 1995) The use of a1-AR antagonists in the treatment of BPH is related to its ability to decrease the tone of the prostatic smooth muscle, cond uciendo to the relief of the symptoms of obstruction. Adrenergic receptors are found throughout the body playing a dominant role in the control of blood pressure, nasal congestion, prostate function and other processes (Harrison et al., 1991). However, there are a number of cloned subtypes of the 1-AR receptor: 1a-AR, a1t >; -AR and a1d-AR (Bruno et al., 1991; Forray et al., 1994; Hirasawa et al., 1993; Ramarao et al., 1992; Schwinn et al., 1995; Weinberg et al., 1994) . A number of laboratories have characterized a1-AR in human prostate by binding with radioactive ligand and functional molecular biological techniques (Forray et al., 1994, Hatano et al., 1994, Marshall et al., 1992, Marshall et al. , 1995; Yamada et al., 1994). These studies provide evidence to support the concept that the a1a-AR subtype constitutes the majority of a1-ARs in human prostatic smooth muscle and regulates contraction in this tissue. These findings suggest that the development of a selective 1a-AR antagonist of the subtype could result in a therapeutically effective agent with a greater selectivity for the treatment of BPH.

BRIEF DESCRIPTION OF THE INVENTION The invention relates to compounds of the Formula where: A is (CH2) n where n is 1-6; R1 is C-6 alkyl, phenyl, substituted phenyl wherein the phenyl substituents are independently selected from one or more of the group consisting of C? -5 alkyl, C-? 5 alkoxy and halogen, phenyl-? C 1-5 alkyl or phenyl-substituted C 1-5 alkyl, wherein the phenyl substituents are independently selected from one or more of the group consisting of Cr 5 alkyl, C 1-5 alkoxy and halogen; R 2 is hydrogen, C 1 -6 alkyl, C 1-5 alkenyl, C 1-5 alkynyl, C 5 phenylalkyl, or substituted phenyl-C 1-5 alkyl wherein the phenyl substituents are independently selected from one or more of the group consisting of C 1-5 alkyl, C 1-5 alkoxy and halogen; E is where: m is 1-5; R3 is hydrogen, C6 alkyl or oxygen, wherein if R3 is oxygen, the dotted line represents a bond and if R3 is C6 alkyl the dotted line does not appear; R 4 is oxygen, hydrogen, C 1-5 alkyl, formyl, carboxy, C 1 -C 5 alkylcarbonyl, C 1 -C 5 alkoxycarbonyl, C 1 -C phenyl alkoxy, phenyl-C 1 alkoxy -5 substituted wherein the phenyl substituents are independently selected from one or more of the group consisting of C 1-5 alkyl, C 1-5 alkoxy and halogen, amido and substituted amido wherein the nitrogen substituents are independently selected from or more of the group consisting of hydrogen, C 5 alkyl, C 1-5 alkoxy and hydroxy, wherein if R 4 is oxygen, the dotted line represents a bond and if R 4 is any other substituent, the dotted line is not present; R is hydrogen, C 1-5 alkyl or taken together with R 6 to form a cyclohexane, cyclopentane or cyclopropane ring, Re is hydrogen, C 1-5 alkyl or taken together with R 5 to form a cyclohexane, cyclopentane or cyclopropane ring and pharmaceutically acceptable salts thereof, These compounds are useful as modulators of the adrenergic receptor. The compounds of this invention selectively bind to the a1a-AR receptor, modulate the activity of said receptor and are more selective for prostatic tissue than for aortic tissue. As such, they represent a viable treatment for disorders modulated by the a1a-AR receptor, which are included but not limited to BPH. In addition this invention contemplates pharmaceutical compositions containing compounds of Formula I, and methods for treating disorders mediated by the 1a-AR receptor with compounds of Formula I. In addition to the compounds of Formula I, this invention contemplates intermediates of the Formula II. These intermediates are useful in the preparation of compounds of Formula I and are as follows: where A is (CH2) n where n is 1-6; R1 is C2-6 alkyl, phenyl, substituted phenyl wherein the phenyl substituents are independently selected from one or more of the group consisting of C1-5 alkyl > C 1-5 alkoxy and halogen, phenyl-C 1-5 alkyl or phenyl-substituted C 1-5 alkyl, wherein the phenyl substituents are independently selected from one or more of the group consisting of C 1-5 alkyl, alkoxy of C1-5 and halogen; R7 is hydrogen, BOC or CBZ. Additionally, this invention contemplates compounds of the formula III. These compounds are useful as intermediates in the preparation of compounds of the formula I and are as follows. where m is 1-5.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a graph showing the effects of compound 5 on intraurethal pressure (IUP) and average blood pressure (MAP) at a concentration of 10 μg / kg of PE in dogs. Figure 2 is a graph showing the effects of compound 12 on IUP and MAP at a concentration of 10 μg / kg of PE in dogs.

DETAILED DESCRIPTION OF THE INVENTION The terms used to describe the invention are commonly used and are known to those skilled in the art. "HBSS" refers to Hank's Balanced Salt Solution. "Independently" means that when there is more than one substituent, the substituents may be different. The term "alkyl" refers to linear, cyclic and branched chain alkyl groups and "alkoxy" refers to O-alkyl wherein alkyl is like the known a1-AR antagonists defined above. "LDA" refers to lithium diisopropylamide and "BOP" refers to benzotriazol-1-yl-oxy-tris- (dimethylamine) -phosphonium hexafluorophosphate. "BOC" refers to t-butoxycarbonyl, "PyBroP" refers to bromo-tris-pyrrolidino-phosphonium hexafluorophosphate, "CBZ" refers to benzyloxycarbonyl and "Ts" refers to toluenesulfonyl. "DCC" refers to 1,3-dicidohexylcarbodiimide, "DMAP" refers to 4-N ', N-dimethylaminopyridine, "EDCI" refers to 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride and " HOBT "refers to 1-hydroxybenzotriazole hydrate. The symbol "Ph" refers to phenyl and "PHT" refers to phthalimido. The term "effective dose" refers to an amount of a compound of the formula I that binds to and / or antagonizes the activity of the a-1a adrenergic receptor. In addition, the term "effective dose" refers to an amount of a compound of formula I which reduces the symptoms of diseases associated with the a-1a adrenergic receptor. The compounds of the invention can be prepared by the following schemes, wherein some schemes produce more than one embodiment of the invention. In those cases, the choice of scheme is a matter of discretion which is within the capabilities of synthetic chemists. The compounds of the formula I in which Ri is phenyl, R 2 is hydrogen, R 3 is oxygen, A is (CH 2) 3 and m is 4, can be prepared as illustrated by scheme 1. In this scheme, the molecules of Formula 1 is prepared in a convergent synthesis in which two halves of the molecule are assembled and finally coupled together. The starting material for a half is an N-substituted mono-piperazine of type 1 a. Treatment of 1a with a soft base such as K2CO3 and an alkylating agent, such as acrylonitrile in an inert solvent such as MeOH at room temperature for 2-24 hours gives the nitrile 1 b. This intermediate can be hydrogenated using Nickel Rainy as a catalyst to yield the intermediate propylamine 1c. The other half of the molecule is assembled using compounds of type 1c as starting materials. The e-caprolactam is treated with a strong base such NaH, in an inert solvent at 0 ° C for about 30 minutes. The formed anion is treated with an alkylating agent such as butyl bromoacetate in an inert solvent such as acetonitrile at room temperature for 2 hours to 2 days to give ester 1e. Hydrolysis of 1e with an acid such as trifluoroacetic acid at room temperature for 2-16 hours gives the acid 1f. Treatment of amine 1c and acid 1f with a peptide-based coupling agent such as BOP and an appropriate amine such as DMAP at room temperature for 1-16 hours gives a compound of formula I, 1g. The BOP can be replaced by other coupling agents. Such agents include, but are not limited to, PyBroP, EDCI, HOBt and the like. Suitable replacements for DMAP include, but are not limited to, N-methylmorpholine, imidazole, DABCO and the like. Scheme 1 can be used to prepare compounds apart from 1g. To prepare the compounds wherein m is 1-5, the appropriately sized lactams known, such as 2-azacyclooctanone, replace e-caprolactam in scheme 1.

SCHEME 1 To prepare the compounds in which Ri is different from phenoxy, 1a is replaced with the known phenylpiperazine derivatives such as JN- (2-t-butoxyphenyl) -piperazine. To prepare the compounds wherein A is (CH2) n and n is 1-6, the acrylonitrile can be replaced with alkylating agents such as 4-chloryronitrile. Alternatively, intermediate 1 c can be prepared by another route as illustrated in scheme 2.

The piperazine derivative 1a is treated with a soft base and with the known phthalimido derivatives such as N- (4-bromyl) phthalimide to give the intermediate 2a. Treatment of 2a with a hydrazine such as M-methylhydrazine in an appropriate solvent such as MeOH or EtOH at reflux, gives the intermediates of type 1c. Alternatively, the piperazine 1a is treated with a soft base and an N-BOC-protected amine such as N-tert-butoxycarbonyl-4-bromylamine to give the corresponding BOC-protected amine. This amine can be deprotected by treatment with an acid such as TFA to give the intermediates of type 1c.

SCHEME 2 2a To prepare the compounds wherein R2 is different from hydrogen, scheme 3 can be used. Treatment of compounds of type 1g with a strong base such as NaH, followed by an alkylating agent such as benzyl bromide gives the compounds of type 3a in 1-5 hours at temperatures of 0-35 ° C.

SCHEME 3 Compounds wherein R 4 is oxygen, C 1-5 alkyl, formyl, carboxy, C 1 -C 5 alkylcarbonyl, C 1 -C 5 alkoxycarbonyl, C 1 -5 alkoxy, phenylalkoxy C 1 5 substituted, amido and substituted amido can be synthesized by scheme 4. For example to prepare compounds wherein R4 is ethoxycarbonyl, m is 2, and R3 is carbonyl, ethyl-2-pyrrolidone-5-carboxylate is treated with a base strong such as NaH, in an inert solvent at 0 ° C for about 30 minutes. The formed anion is treated with an alkylating agent such as t-butyl bromoacetate in an inert solvent such as acetonitrile at room temperature for two hours to 2 days to give the ester 4a. Hydrolysis in acidic medium of 4a with trifluoroacetic acid at room temperature for 2-16 hours gives the acid 4b. Coupling of the 4b acid and the amine intermediate 1c with a peptide-based coupling agent such as PryBOP gives a compound of the formula I, 4c. The ethyl ester of compound 4c can be treated with a variety of agents to give derivatives such as amides, carboxylic acids, aldehydes, etc., wherein the reactants and the reaction conditions are within the knowledge of those skilled in the art.

SCHEME 4 4c Although the claimed compounds are useful as 1-AR modulators, some compounds are either preferred or particularly preferred. Preferred compounds of the invention include: Particularly preferred "Ri" s are Cr5 alkyl. Particularly preferred "R" s are hydrogen, C 1-5 alkenyl and C 1-5 alkynyl, particularly preferred "E" s are The particularly preferred "m" is 3. The particularly preferred R3 is oxygen. The particularly preferred R 4 is hydrogen. Particularly preferred "A" s are (CH2) n where n is 2-4. Particularly preferred compounds of formula II include compounds wherein A is 2 or 3, R is C2-6 alkyl, and R7 is hydrogen. Particularly preferred compounds of formula III include compounds wherein m is 3. The compounds of formula I can be used in pharmaceutical compositions for treating patients with disorders related to the modulation of a1 adrenergic receptor activity. The preferred route is oral administration, however the compounds of the invention can be administered by other methods, including but not limited to intravenous infusion. Oral doses vary approximately from 0.01-100 mg / kg daily. The preferred oral dosage range is from 0.05-1.0 mg / kg daily. The doses for infusion can vary from 0.001-100 mg / kg / min of the inhibitor, with a pharmaceutical vehicle during a period that varies from several minutes to several days. The pharmaceutical compositions can be prepared using conventional pharmaceutical excipients and formulation techniques. Oral dosage forms may be elixirs, syrups, capsules, tablets, and the like. Where the typical solid carrier is an inert substance such as lactose, starch, glucose, methylcellulose, magnesium stearate, dicalcium phosphate, mannitol and the like; and typical liquid oral excipients include ethanol, glycerol, water and the like. All excipients may be mixed as required with disintegrants, diluents, granulating agents, lubricants, binders and the like using conventional techniques known to those skilled in the art of preparing dosage forms. Parenteral dosage forms can be prepared using pharmaceutically acceptable carriers or diluents including, but not limited to, water or other sterile vehicle. Typically the compounds of the formula I are isolated and used as the free bases, however the compounds can be isolated and used as their pharmaceutically acceptable salts. Examples of such salts include, but are not limited to, those obtained from hydrobromic, hydroiodic, hydrochloric, perchloric, sulfuric, maceic, fumaric, melic, tartaric, citric, benzoic, mandelic, methanesulfonic, hydroethanesulfonic, benzenesulfonic, oxalic acids. , pam, 2-naphthalenesulfenic, p-toluenesulfonic, cyclohexanesulfamic and saccharinic. The following examples are included to properly illustrate the invention. These examples do not limit the invention. They are suggested as a method to practice it. Those skilled in the art will find other methods for practicing the invention, which will be readily apparent to them. However, these methods are considered within the scope of this invention.

EXAMPLES OF PREPARATION EXAMPLE 1 1 - . 1 - . 1 - . 1- (2-phthalimidoethi0-4- (2-isopropyloxyphenyl) piperazine Comp.

N- (2-bromoetyl) phthalimide (7.6 g, 30 mmol) and K2CO3 (6.2 g, 45 mmol) were added to a solution of N-1- (2-isopropoxyphenyl) piperazine (6.6 g, 30 mmol). ) in acetonitrile (100 mL) and the resulting mixture was heated to reflux for 2 days. The mixture was concentrated in vacuo and purified by column chromatography on silica gel using EtOAc / hexanes (30:70) as an eluent which yielded the title compound as a solid: MS m / z 394 (MH +).

EXAMPLE 2 1- (2-Aminoethyl) -4- (2-2-iso-propyloxyphenyl) p -perazine Comp. 2 A solution of compound 1 (7.5 g, 19 mmol) in EtOH (70 mL) was stirred for 10 minutes at room temperature. Methylhydrazine (20 mL) was added and the mixture was heated to reflux for 2.5 hours. The mixture was cooled to room temperature and the resulting solid precipitate was removed by filtration. The filtrate was concentrated in vacuo yielding the title compound as a solid which was used without purification: MS m / z 264 (MH +).

EXAMPLE 3 1-t-Butoxycarbonyl? Netl-2-piperidone Comp. 3 95% sodium hydride (1.67 g, 66 mmol) was added to a stirred solution of d-valerolactam (5.95 g, 62 mmol) in toluene (100 mL) at 0 ° C and the resulting suspension was stirred for 1 hour. T-Butyl bromoacetate (8.86 mL, 60 mmol) was added dropwise and the reaction mixture was warmed to room temperature and stirred for 10 hours. Saturated aqueous NH 4 Cl was added and the resulting organic layer was washed with successive portions of brine and H 2 O. The combined organic layers were dried (Na 2 S 4) and concentrated in vacuo to give compound 3 as an oil.

EXAMPLE 4 1-Carboxymethyl-2-piperidone Comp. 4 Trifluoroacetic acid (15 mL) was added to a stirred solution of compound 2 (12.93 g, 61 mmol) in methylene chloride (30 mL) under Na. This mixture was stirred for 4 hours and concentrated in vacuo to give the title compound as a solid: MS m / z 158 (MH +).

EXAMPLE 5 N-retyl-2- (2-iso-propyloxyphenyl) piperazin-4-yl) 1-p '- (2-oxypiperidine-D-tatamidamide Compound 5 A solution of compound 2 (3.61 g, 23 mmol) in methylene chloride ( 10 mL) was added to a solution of compound 4 (5.0 g, 19 mmol) in methylene chloride (10 mL). PyBroP (10.72 g, 23 mmol), DMAP (3.85 g, 31 mmol) and N-methylmorpholine were added. (2.53 mL, 23 mmol) and the mixture was stirred at room temperature under N2 for 10 hours.The resulting mixture was washed with a portion of aqueous sodium bicarbonate, brine and H2O.The combined organic layer was dried (Na2SO4) and Concentrate in vacuo The residue was purified by MPLC on silica gel using EtOAc / MeOH / triethylamine (90: 5: 5) as an eluent to give the title compound as an oil: MS m / z 403 (MH +). Treatment of the isolated compound with an equimolar portion of citric acid in ethyl acetate yielded the citrate salt of the title compound as a solid.

EXAMPLE 6 N-retyl-2- (2-iso-propyloxyphenyl) piperazin-4-yl) N-methyl-ri '- (2-oxypiperidinium-5-acetamidamide Compound 6 Sodium hydride (95% technical 10.6 mg, 0.44 mmol) was added to a stirred solution of compound 5 (140.5 mg, 0.35 mmol) in THF (5 mL) at 0 ° C and the resulting suspension was stirred for 30 minutes.Methyl iodide (0.37 mmol) was added. dropwise and the mixture was stirred overnight at room temperature The residue was concentrated in vacuo, dissolved in ethyl acetate and washed with successive portions of aqueous saturated ammonium chloride solution, brine and water. The combined organic was dried (Na2SO4) and concentrated in vacuo to give the title compound as a solid: MS m / z 417 (MH +).

BIOLOGICAL EXAMPLES The activity and biological selectivity of the compounds of the invention was demonstrated by the following in vitro tests. The first test tested the ability of the compounds of formula I to bind to the a1a-AR, a1-AR and a1rj-AR receptors attached to the membrane.

EXAMPLE 14 The DNA sequences of the three cloned human 1-AR subtypes have been published. In addition, the cloned cDNA molecules have been expressed both transiently in COS cells and stably in a variety of mammalian cell lines (HeLa, LM (tk-), CHO, fibroblast rat-1) and it has been shown that they retain the activity of binding to the radioactive ligand and the ability to couple in the hydrolysis of phosphoinositide. Information on published DNA sequences was used to design primers useful in RT-PCR amplification of each subtype to obtain cloned cDNA molecules. Poly A + RNA was obtained from human sources commercially available including samples from the hippocampus and the prostate, sources that have been cited in the literature. For the primary selection, a radioactive ligand binding test was used which uses membrane preparations from cells expressing the individual cloned receptor cDNAs. Radioactively labeled ligands with binding activity on all three subtypes (non-selective) are commercially available ([1251] -HEAT, [3h] -prazosin). Each a1 receptor subtype was cloned from poly A + RNA by the standard polymerase-reverse transcription chain reaction (RT-PCR) method. The following sources of poly A + RNA were used for the cloning of the subtypes of human 1: a1a-AR, hippocampus and prostate, a1b-AR of human hippocampus, a1d-AR of human hippocampus. The resulting cDNA molecules were cloned into the mammalian expression vector pcDNA3 (Invitrogen Corp., San Diego CA). The sequence for each DNA was determined to verify and detect any possible mutation introduced during the amplification procedure. Any deviation in the sequence from the published consensus for each receptor subtype was corrected by site-directed mutagenesis. The three subtypes of a1-AR (a, b, d) were transfected into COS cells using a standard DEAE-dextran procedure with a chloroquine shock. In this procedure, each tissue culture box (100 mm) was inoculated with 3.5 x 10 6 cells and transfected with 10 μg of DNA. Approximately 72 hours after the transfection, the cells were harvested and the COS membranes were prepared. The transfected COS cells from 25 boxes (100 mm) were scraped and suspended in 15 mL of TE buffer (50 mM Tris-HCl, 5 mM EDTA, pH 7.4). The suspension was broken with a homogenizer. This was then centrifuged at 1000 xg for 10 minutes at 4 ° C. The supernatant was centrifuged at 34,500 xg for 20 minutes at 4 ° C. The pellet was resuspended in 5 mL of TNE buffer (50 mM Tris-HCl, 5 mM EDTA, 150 mM NaCl, pH 7.4). Aliquots of the resulting preparation were taken from membranes and stored at -70 ° C. The protein concentration was determined after membrane solubilization with TritonX-100. The ability of each compound to bind to each of the a1-AR subtypes was evaluated in a receptor binding assay. We used [1251J-HEAT, a non-selective a1-AR ligand, as the radioactively labeled ligand. Each well of a 96-well plate received: 140 μL of TNE, 25 μL of [1251] -HEAT diluted in TNE (50,000 cpm, final concentration 50 pM), 10 μL of the test compound diluted in DMSO (final concentration 1 pM) -10 μM), 25 mL of COS cell membrane preparation that express one of the three subtypes of a1-AR (0.05-0.2 mg protein of membrane). The plate was incubated for 1 hour at room temperature and the reaction mixtures were filtered through a Packard GF / C filtration plate from Unifilter. The filter plate was dried for 1 hour in a vacuum oven. Flash liquid (25 mL) was added to each well, and the filtration plate was counted in a Packard Topcount flash counter. The data was analyzed using the GraphPad Prism program. Tables A and B list the Cl 50 values expressed in nanomolar concentration for selected compounds of the invention in all receptor subtypes.

TABLE A Comp. i A R2 F m a1a-AR a1 b-AR a1d-AR * i-prop CH2 H H 3 8.7 46120 372 6 ¡-prop CH2 CH3 H 3 53 763900 650 7 Í-prop CH2 CH2CHCH2 H 3 103 172500 372 8 j-prop CH2 CH2 (C) (CH) 3 H 3 237 170200 358 9 i-prop CH2 CH2Ph H 3 88 4226 348 i-prop CH2 H C02C2H5 2 20 26310 260 11 i-prop CH2 H H 4 18 3536 505 12 CH3 (CH2) 2 H H 3 98 109000 30530 a * "indicates a citrate salt TABLE B Compound R1 R2 m a1 a-AR a1 b-AR a1 d-AR 13 i-prop CH2 18 1932 189 EXAMPLE 15 The antagonist activity of the selected compounds of the formula I was demonstrated by the following evaluation. The binding of an agonist to a1-AR causes the activation of PLC through mechanisms coupled to the G protein (Minneman and Esbenshade, 1994). PLC catalyzes the hydrolysis of phosphatidyl inositol 4,5-bisphosphate (PIP2) generating two molecules of second messenger, 1, 4,5-triphosphate of inositol (IP3) and diacylglycerol (DAG) and finally resulting in the mobilization of intracellular stores of calcium. Successes from the primary evaluation test that showed selectivity to inhibit the binding of the radioactive ligand to a1a-AR were evaluated for activity to antagonize cytosolic calcium mobilization in cell lines stably expressing the individual receptor subtypes.

Preparation of stable cell lines expressing each receptor subtype The alpha 1 (a, b, d) adrenergic receptor subtypes in the pcDNA3 vector were transfected into HEK293 cells (human embryonic kidney cells) to form stable cell lines expressing to the receiver. The transfection was used using the cationic lipid reagent DMRIE-C (GibcoBRL) mixed with 2-3 ug of DNA and low serum OPTI-MEM1 medium (GibcoBRL). Cells in 100 nm tissue culture plates were layered with the lipid-DNA complex and incubated at 37 ° C, 5% CO2 for 5-6 hours. Then the growth medium containing serum was added and the cells were incubated for another 48 hours. After this incubation each plate was separated 1: 5 in selection medium containing 250, 300 or 350 ug / ml of the antibiotic G418 (geneticin). The plates were fed every 4 days with the appropriate selection medium. After approximately 3 weeks, the colonies were chosen for each subtype from the selection plates with 300 ug / ml G418. The colonies expanded and then froze. Twelve cell lines of each subtype were evaluated for binding to the alpha 1 adrenergic receptor using a whole cell receptor binding assay. The positive cultures were subsequently analyzed by the calcium mobilization test. HEK293 cells expressing a1a-AR from human were extracted with trypsin and washed once with HBSS. The cell pellet was resuspended in HBSS with 0.05% BSA at a density of 1-5x106 cells / ml. A solution of 5mM Fluo-3 (in 2/3 volumes of DEMO and 1/3 volumes of pluronic acid) was added to the cell suspension, giving a final concentration of Fluo-3 of 5 μM. The cells were then incubated by gently rotating at room temperature for 1 hour in the dark. After incubation, cells were washed 3x with HBSS and resuspended in HBSS with 1.25 mM CaCl2 to 0.7x106 cells / ml. Aliquots (100 μl) were pipetted into each well of a 96-well microplate. Calcium mobilization was induced with norepinephrine (10 uM) at room temperature. Two minutes before the test, the antagonists were added to the cells using a 96-well pipettor. After this, the agonist was added and the fluorescent signal was monitored for 2-3 minutes using FLIPR (Molecular Devices, USA). Compound 5 inhibited the mobilization of solid calcium at a Cl50 of 99 μM.

EXAMPLE 16 The antagonist activity and selectivity of the compounds of the invention for the prostatic tissues on the aortic tissues as well as their antagonists was demonstrated as follows. The contractile responses of rat prosthetic tissue and rat aortic tissue were examined in the presence and absence of antagonist compounds. As an indication of antagonism selectivity, the effects of the test compounds on the vascular smooth muscle contractility (a1D-AR and a1d-AR) were compared with the effects on prosthetic smooth muscle (a1a-AR). Prostatic tissue strips and aortic rings were obtained from male Long Evans rats weighing 275 grams and sacrificed by cervical dislocation. The prostate tissue was placed under a gram of tension in a 10 ml bath containing phosphate buffered solution pH 7.4 at 32 ° C and the isometric tension was measured with force transducers. The aortic tissue was placed under 2 grams of tension in a 10 ml bath containing phosphate buffered solution pH 7.4 at 37 ° C. The ability of the test compounds to reduce the norepinephrine-induced contractile response by 50% (Cldo) was determined. - Compound 5 inhibited the contractile response in aortic tissue with an IC50 of 31.9 μM and in prostate tissue with a Cl50 of 1.3 μM.

EXAMPLE 17 The selected compounds of the invention were tested for their ability to antagonize increases in intraurethral pressure induced by phenylephrine (PE) in dogs. The selectivity of these compounds was demonstrated by comparing their effect on the PE-induced increases in mean arterial blood pressure (MAP) in the dog. Small male size hounds were anaesthetized and catheterized to measure intraurethral pressure (IUP) in the prostatic urethra. Mean arterial pressure (MAP) was measured using a catheter placed in the fermoral artery. Initially the dogs were administered six doses of intravenous bolus (1 a = 32 mg / kg) of phenylephrine (PE) to establish a control in the dose response curve of agonist. The IUP and MAP values were recorded following each dose until the IUP returned to the baseline. The dogs were then given an intravenous bolus dose of the antagonist compound, followed by intravenous administrations of PE in ascending doses, such as in the dose response control curve of the agonist. The measurements for IUP and MAP following each administration of PE were recorded. The antagonist compound was tested over a dose range of 3 to 300 ug / kg in increments of half the logarithm. The interval between the antagonist dose was at least 45 minutes and three experiments were performed for each dose level for each test compound. Figures 1 and 2 below illustrate the percentage of average reduction in IUP and MAP for compounds 5 and 12 respectively.

REFERENCES Breslin D, Fields DW, Chou TC, Marion DN, Kane M, Vaughan ED, and Felsen D (1993) Investigative urology: medical management of benign prostatic hyperplasia: a canine model comparing the in vivo efficacy of alpha-1 adrenergic antagonists in the Prostate J. Urol. 149: 395-399. Bruno JF, Whittaker J, Song J, and Berelowitz M. (1991) Molecuate cloning and sequencing of a cDNA encoding a human a1A adrenergic receptor. Biochem. Biophys. Res. Commun. 179: 1485-1490. Bylund DB. Eikenberg DC, Hieble JP, Langer SZ, Lefkowitz RJ, Minneman KP, Molinoff PB, Ruffolo RR, and Trendelenburg U (1994) IV. International Union of Pharmacology nomenclature of adrenoceptors. Pharmacol. Rev. 46: 121-136. Carruthers SG (1994) Adverse effects of a1 -adrenergic blocking drugs. Drug Safety 1 1: 12-20. Faure C, Gouhier C, Langer SZ, and Graham D (1995) Quantification of a1-adrenoceptor subtypes in human tissues by competitive RT-PCR analysis. Biochem. Biophys. Res. Commun. 213: 935-943. Flavahan NA and VanHoutte PM (1986) a-Adrenoceptor classification vascular smooth muscle.Trends Pharmacol. Sci. 7: 347-349. Ford APDW, Arredondo NF, Blue DR, Bonhaus DW, Jasper J Dava EM, Lesnick J, Pfister JR, IA Shieh, Vimont RL, WilliaEM RJ, McNeal JE, Stamey TA, and Clarke DE (1996) RS-17053 (N- [2- (2- CyclopropyImethoxyphenoxy) ethiI] -5-chloro-a, a-dimethyl-1H-indole-3-ethanamine hydrochloride), a selective a1A-adrenoceptor antagonist, low affinity displays for functional a1 -adrenoceptors in human prostate : Implications for adrenoceptor classification. Mol. Pharmacol. 49: 209-215. Forray C, Bard JA, Wegzel JM, Chiu G, Shapiro E, Tang R, Lepor H, Hartig PR, Weinshank RL, Branchek TA, and Gluchowski C (1994) The a1 -adrenergic receptor that mediates smooth muscle contraction in human prostate has the pharmacological properties of the cloned human a1c subtype. Mol. Pharmacol. 45: 703-708. Gormley G, Stoner E, Bruskewitz RC et al. (1992) the effects of finasteride in men with benign prostatic hyperplasia. N. Engl. J. Med. 327: 1 185-1191. Hatano A Takahashi H, Tamaki M, Komeyama T, Koizumi T, and Takeda M (1994) Pharmacological evidence of distinct a1 -adrenoceptor subtypes mediating the contraction of humanprostatic urethra and peripheral artery. Br. J. Pharmacol. 113: 723-728. Harrison JK, Pearson WR, and Lynch KR (19911) Molecular characterization of a1- and a1 -adrenoceptors. Trends Pharmacol. Sci. 12: 62-67. Hieble JP and Caine M (1986) Etiology of benign prostatic hyperplasia and approaches to pharmacological management. Fed. Proc. 45: 2601. Hirasawa A, Horie K, Tanaka T, Takagaki K, Murai M, Yano J, and Tsujimoto G (1993) Cloning, functional expression and tissue distribution of human cDNA for the a1 c-adrenergic receptor. Biochem. Biophys. Res. Common. 195: 902-909. Holck CM, Jones CHM, and Haeusler G (1983) Differential interactions of clonidine and methoxamine with postsynaptic a-adrenoceptors of rabbit main pulmonar / artery. Cardiovasc. Res. 5: 240-248. Lepor H and Rigaud G (1990) The efficacy of transurethral resection of the prostate in men with modérate symptoEM of prostatism. J. Urol. 143: 533-537. Lepor H, Auerbach S, Puras-Baez A et al. (1992) A randomized, placebo-controlled multi-center study of the efficacy and safety of terazosin in the treatment of bening prostatic hyperplasia. J. Urol. 148: 1467-1474. Lepor H (1995) a-Blockade for benign prostatic hyperplasia (LA BPH) J. Clin. Endocrinol Metab. 80: 750-753. Marshall I, Burt RP, Andersson PO, Chapple CR, Greengrass PM, Johnson Gl, and Wyllie MG (1992) Human a1c-adrenoceptor: functional characterization in prostate. Br. J. Pharmacol. 1 12: 59P. Marshall I, Burt RP, and Chapple CR (1995) Noradrenaline contraction of human prostate by a1A- (a1 C-) subtype adrenoceptor. Br. J. Pharmacol. 1 15: 781-786. Mebust WK, Holtgrewe HL, Cockett ATK, and Peters PC (1989) Transurethral prostatectomy: immediate and postoperative complication: a cooperative study of 13 participating institutions evaluating 3,885 patients J. Urol., 141: 243-247.

Minneman KP, Han C and Abel PW (1988) Comparison of a1-adrenergic receptor subtypes distinguished by chloroethylclonidine and WB4101. Mol. Pharmacol. 33: 509-514. Minneman KP and Esbenshade TA (1994) a1 -Adrenergic receptor subtypes. Annu. Rev. Pharmacol. Toxicol 34: 117-133. Morrow AL and Créese I (1986) Characterization of alpha 1-adrenergic receptor subtypes in rat brain: A reevaluation of [3H] WB4101 and [3H] prazosin binding. Mol. Pharmacol. 29: 321-330. Muramatsu I (1992) A pharmacological perspective of a1-adrenoceptors: subclassification and functional aspects, in a-Adrenoceptors (Fujiwara M, Sugimoto T, and Kogure K, eds.). Excerpta Medica Ltd., Tokyo, 193-202. Muramatsu I, Oshita M, Ohmura T, Kigoshi S, Akino H, Gobara M, and Okada K (1994) Pharmacological characterization of a1 -adrenoceptor subtypes in the human prostate: functional and binding studies. Br. J. Urol. 74: 57-577. Oesteriing JE (1995) Benign prostatic hyperplasia. Medical and minimally invasive treatment options. N. Engl. J. Med. 332: 00-109. Price DT, Lefkowitz RJ, Caron MG, Berkowitz d, and Schwinn DA (1994) Localization of mRNA for three distinct a1 -adrenergic receptor subtypes in human tissues: implications for human a-adrenergic physiology. Mol. Pharmacol. 45: 171-175.

Ramarao CS, Kincade Denker JM, Pérez DM, Gaivin RJ, Riek RP, and Graham RM (1992) Genomic organization and expression of the human a1 B-adrenergic receptor. J. Biol. Chem. 267: 21936-21945. Schwinn DA, Johnston Gl, Page SO, Mosley MJ, Wilson KH, Worman NP, Campbell S, Fidock MD, Furness LM, Parry-Smith DJ, Peter B, and Bailey DS (1995) Cloning and pharmacological characterization of human alpha-1 adrenergic receptors: sequence corrections and direct comparison with other species homologues. JPET 272: 134-142. Weinberg DH, Trivedi P, Tan CP, Mitra S, Perkins-Barrow A, Borkowski D, Strader CD, and Bayne M (1994) Cloning, expression and charecterization of human to adrenergic receptors a1A, a1 B, and a1 C. Biochem. Biophys. Res. Commun. 201: 1296-1304. Weis KA, Epstein RS, Huse DM, Deverka PA and Oster G (1993) The costs of prostatectomy for benign prostatic hyperplasia. Prostate 22: 325-334. Wennberg JE, Roos N, Sola L, Schori A, and Jaffe R (1987) Use of claiEM data systeem to evaluate health care outcomes: mortality and reoperation following prostatectomy. JAMA 257: 933-936. Yamada S, Tanaka C, Kimura R, and Kawabe K (1994) Alpha 1-adrenoceptors in human prostate: characterization and binding characteristics of alpha 1 -antagonists. Life Sci. 54: 1845-1854.

Claims (23)

NOVELTY OF THE INVENTION CLAIMS

1. - A compound of the formula I where: A is (CH2) n where n is 1-6; R1 is C6-6 alkyl, phenyl, substituted phenyl wherein the phenyl substituents are independently selected from one or more of the group consisting of C1-5 alkyl, C1-5 alkoxy and halogen, phenyl-C1 alkyl Or substituted phenyl-C 1 -C 5 alkyl, wherein the phenyl substituents are independently selected from one or more of the group consisting of C 1-5 alkyl, C 1-5 alkoxy and halogen; R 2 is hydrogen, C 1 -6 alkyl, C 1-5 alkenyl, C 1-5 alkynyl, phenyl-C 1-5 alkyl, or substituted phenyl-C 1-5 alkyl wherein the phenyl substituents are independently selected from one or more of the group consisting of C -? - alkyl, C 1-5 alkoxy and halogen; E is where: m is 1-5; R3 ßs hydrogen, C1-6 alkyl or oxygen, wherein if R3 is oxygen, the dotted line represents a bond and if R3 is C-? 6 alkyl, the dotted line does not appear; R 4 is oxygen, hydrogen, C 1-5 alkyl, formyl, carboxy, C 1 -C 5 alkylcarbonyl, C 1 -C 5 alkoxycarbonyl, Cr 5 phenyl alkoxy, C 1-5 phenyl alkoxy substituted wherein the phenyl substituents are independently selected from one or more of the group consisting of C 1-5 alkyl, C 1-5 alkoxy and halogen, amido and substituted amido wherein the nitrogen substituents are independently selected from one or more of the group consisting of hydrogen, C 1-5 alkyl, C 1-5 alkoxy and hydroxy, wherein if R 4 is oxygen, the dotted line represents a bond and if R 4 is any other substituent, the dotted line is not present; R5 is hydrogen, C1-5 alkyl or taken together with R6 to form a ring of cyclohexane, cyclopentane or cyclopropane; Re is hydrogen, C 1-5 alkyl or taken together with R 5 to form a ring of cyclohexane, cyclopentane or cyclopropane; and pharmaceutically acceptable salts thereof.

2. The compounds according to claim 1, further characterized in that Ri is C-? -6 alkyl, n is 2-4 and R2 is hydrogen, C-? 6 alkyl or C2-6 alkenyl.

3. The compounds according to claim 2, further characterized in that E is

4. - The compounds according to claim 2, further characterized in that R3 is oxygen and R4 is hydrogen, (C- | 5) alkoxycarbonyl or oxygen.

5. The compounds according to claim 4, further characterized in that R4 is hydrogen and E is

6. The compounds according to claim 5, further characterized in that m is 2 to 5.

7. - A compound and pharmaceutically acceptable salts thereof which are selected from the group consisting of N- [ethyl-2- (2-isopropyloxyphenyl) piperazin-4-yl] - [r- (2-oxipiperidinyl)] acetamide, N- [ethyl-2- (2-isopropyloxyphenyl) piperazin-4-yl] -N-methyl- [1 '- (2-oxipiperidinyl)] acetamide and N- [propyl-3- (2-ysoprop Loxyphenyl) piperazin-4-yl] - [1 '- (2-oxipiperidinyl)] acetamide.

8. A compound N- [ethyl-2- (2-isopropyloxyphenyl) piperazin-4-yl] - [1 '- (2-oxipiperidinyl)] acetamide and the pharmaceutically acceptable salts thereof.

9. A pharmaceutical composition comprising a compound according to claim 1 and a pharmaceutically acceptable carrier or diluent.

10. A pharmaceutical composition comprising a compound according to claim 6 and a pharmaceutically acceptable carrier or diluent. 1.

A pharmaceutical composition comprising a compound according to claim 8 and a pharmaceutically acceptable carrier or diluent.

12. The use of a compound according to claim 1, for the manufacture of a medicament for treating a disease mediated by the a-1a adrenergic receptor in a patient.

13. The use of a compound according to claim 6, for the manufacture of a medicament for treating a disease mediated by the a-1a adrenergic receptor in a patient.

14. The use of a compound according to claim 8, for the manufacture of a medicament for treating a disease mediated by the a-1a adrenergic receptor in a patient.

15. The use according to claim 14, wherein the dose is 0.01-100 mg / kg daily.

16. The use according to claim 15, wherein the dose is 0.05-1.0 mg / kg daily.

17. The use of a compound of the formula I for the manufacture of a medicament for treating benign prostatic hyperplasia in a patient.

18. A compound of formula II II where A is (CH2) n where n is 1-6; Ri is C2-6alkyl, phenyl, substituted phenyl wherein the phenyl substituents are independently selected from one or more of the group consisting of C? -5alkyl, C-? - alkoxy and halogen, phenyl-alkyl C1-5 or phenyl-substituted C 1-5 alkyl, wherein the phenyl substituents are independently selected from one or more of the group consisting of C 1-5 alkyl, C 1-5 alkoxy and halogen; R7 is hydrogen, BOC or CBZ.

19. - The compounds according to claim 18, further characterized in that n is 2-4 and Ri is branched C2-βalkyl.

20. The compounds according to claim 18, further characterized in that R7 is hydrogen or BOC.

21. A compound selected from the group consisting of 1- (2-aminoethyl) -4- (2-2-isopropyloxyphenyl) piperazine, 1- (3-aminopropyl) -4- (2-2-isopropyloxypheni) piperazine and 1- (4-aminobutyl) -4- (2-2-isopropyloxyphenyl) -piperazine.

22. A 1- (aminoethyl) -4- (2-2-isopropyloxy) phenyl-piperazine compound.

23. A compound of formula III where m is 1, 3, 4 or 5. 24.- The compounds according to claim 23, further characterized in that m is 3-5. 25.- A 1-t-butoxycarbonylmethyl-2-piperidone compound.