MXPA99007329A - Process for the preparation of piperidines substitui - Google Patents

Abstract

The present invention concerns a process for the preparation of a compound of formula I or salts thereof (See Formula) characterized in that the process comprises a) Hydroboration of a compound of formula 2 (See Formula) In such formula A is arylene; R1 is -C * R4R4R4, R4 is an -O-alkyl, -O-cycloalkyl, -O-alkenyl, -O-aryl, -O-aralkyl, -O-aralkoxyalkyl, -O-alkylsulfonyl, -O-arylsulfonyl, chlorine, bromine or iodine, R4 hydrogen, R4 is an aryl, R4 is an alkyl, cycloalkyl, aryl, alkoxyalkyl or hydroxyalkyl, and C4 is an asymmetric carbon atom. b) optionally followed by an isolation of the stereoisomer desired

Description

PROCESS FOR THE REPAIR OF SUBSTITUTE PIPERIDINES The invention describes a novel process for the preparation of substituted piperidines. More particularly, the invention describes the preparation of: and compounds of formula 1 1 And you get out of this, where A is arylene; R: is -C * RXR "; R ^ is an -O-alkyl, -O-cycloalkyl; -O-alkenyl, -O-aryl, -O-aralkyl, -O-aralkoxyalkyl, -O-Alkylsulfonyl, -O-arylsulfonyl, chlorine, bromine or iodine.

R 'hydrogen; R "is an aryl; REF .: 30797 - Ra is an alkyl, cycloalkyl, aryl, alkoxyalkyl hydroxyalkyl, • And C * is an asymmetric carbon atom.

The compounds of formula 1 are new and can be used as the chiral component block in the preparation of renin inhibitors, especially disubstituted renin inhibitors as described in WO 97/09311 e.g. 1- [2- [7- [(3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -piperidine-3-yloxymethyl] -naphthalen-2-yloxy] -ethyl] -4-methyl-piperazine and (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- (1,2,3,4-tetrahydro) -quinoline-7-ylmethoxy) -piperidine. The synthesis of optically active renin inhibitors via conventional resolution of racemates is described in WO 97/09311 resulting in a considerable loss of product. The present invention provides a process that avoids the disadvantages of the previous process.

According to the present invention, the above compounds of formula 1 or salts thereof can be prepared by a process characterized in that it comprises: a) hydroboration of a compound of formula _2 in such a formula R1, R2 and A are as defined above; b) optionally followed by isolation of the desired stereoisomer.

The term "alkyl" means alone or in combination with a branched or unbranched alkyl group containing from 1 to 8 carbon atoms, preferably from 1 to 6 carbon atoms. Examples of branched or unbranched Ci-Cß alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, isomeric pentyls, isomeric hexyl, isomeric heptyls, preferred isomeric and ethyl octyl, n -propyl, and isopropyl and particularly preferred methyl.

The term "cycloalkyl" means alone or in combination with a cycloalkyl ring containing from 3 to 8 carbon atoms and preferably a cycloalkyl ring containing from 3 to 6 carbon atoms. Examples for the cycloalkyl Cj-Cb are cyclopropyl, methyl-cyclopropyl, dimethyl-cyclopropyl, cyclobutyl, methyl-cyclobutyl, cyclopentyl, methyl-cyclopentyl, cyclohexyl, methyl-cyclohexyl, dimethyl-cyclohexyl and cycloheptyl.

The term "alkenyl" means alone or in combination with alkenyl groups containing from 2 to 8 carbon atoms. Examples of alkenyl groups include vinyl, allyl, isopropenyl, pentenyl, hexenyl, heptenyl, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, 1-propenyl, 2-butenyl, 2-ethyl-2-butenyl, and the like. An aryl is preferred.

The term "aryl" means alone or in combination with a phenyl group or a naphthyl group eJL which can be substituted by one or more substituents selected from alkyl, cycloalkyl, alkoxy, halogen, carboxy, alkoxycarbonyl, hydroxy, amino, nitro, trifluoromethyl, and the like. Examples of aryl substituents are phenyl, tolyl, methoxyphenyl, fluorophenyl, chlorophenyl, hydroxyphenyl, trifluoromethylphenyl, l-naphthyl, and 2-naphthyl.

The term "arylene" means alone or in combination with a phenylene group or a naphthylene group which can be additionally substituted by one or more substituents selected from alkyl, halogen, nitro, cycloalkyl, alkoxy, hydroxy, amino, preferably halogen alkyl and nitro. Examples of arylene are ortho-phenylene, meta-phenylene, para-phenylene, toluenes, methoxyphenylenes, fluorophenylenes, chlorophenylenes, and naphthylenes. Preferred - is the phenylene wherein the substituents of the phenylene which is defined by the formula 1 are placed in the ortho, meta, or preferential position for, for the one to the other and in which one or more additional substituents selected of alkyl, halogen, and nitro can occur in the arylene cycle. Especially the preferred substituents are methyl, chlorine, and nitro. Particularly preferred is unsubstituted phenylene and especially unsubstituted para-phenylene.

The term "alkoxy" means alone or in combination with the -O-alkyl group, wherein the alkyl is as defined above. Some examples are santoxyto, n-propyloxy, and iso-propyloxy. Preferred is methoxy.

The term "alkoxyalkyl" means alone or in combination with an alkyl group, wherein a hydrogen is substituted by an alkoxy group. Some examples are methoxymethyl, ethoxymethyl and 2-methoxymethyl. Particularly preferred is methoxymethyl.

The term "aralkyl" means alone or in combination with an alkyl group wherein a hydrogen is substituted by an aryl group. Preferred - it's benzyl.

The term "hydroxyalkyl" means either alone or in combination with an alkyl group wherein a hydrogen is substituted by a hydroxy group. Some examples are hydroxymethyl, 1-hydroxyethyl and 2-hydroxyethyl. Preferred is hydroxymethyl.

The term "aralkoxyalkyl" means alone or in combination with an alkyl group, wherein a hydrogen is substituted by an alkoxy group in which a hydrogen is substituted by an aryl group. A preferred example for aralkoxyalkyl is 3- (2-methoxy-benzyloxy) -propyl.

The term "alkylsulfonyl" means alone or in combination with a sulfonyl group which is substituted by an alkyl group. The alkyl group can be replaced by a halogen. Preferred examples are methylsulfonyl and trifluoromethylsulfonyl.

The term "arylsulfonyl" means salo or in combination with a sulfonyl group which is substituted by an aryl group. Preferred is the tosyl group.

The term "salts" means compounds which are formed by the reaction of compounds of formula 1 with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like, and organic acid such such as acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, malic acid, malonic acid, succinic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanol sulfonic acid, ethanolsulfonic acid, p-toluenesulfonic acid, salicylic acid, and the like. The term salts includes solvates and particularly hydrates of such salts.

The term "halogen" means fluorine, chlorine, bromine, iodine, and preferably chlorine and bromine. More preferably chlorine.

The term "anion" means an atom, a group of atoms or a molecule with a negative charge. This load can be a multiple or individual load. Examples of anions are halogen anions, S? X, POX. Particularly preferred is the C1- anion.

The term "asymmetric carbon atom * (C *)" means a carbon atom with four different substituents. According to the Cahn-Ingold-Prelog Convention, the asymmetric carbon atom can be of the "R" or "S" configuration. A preferred example of an asymmetric carbon atom C * is shown in the following formula Wherein the asymmetric carbon atom C * is of the R configuration The term "-0-" in groups such as -O-alkyl, -O-cycloalkyl, -O-alkenyl, -O-aryl, -O-benzyl, -O-aralkoxyalkyl, -O-alkylsulfonyl, -O- Arylsulfonyl, they mean an oxygen with a free valence. For example -O-alkyl means an alkoxy and -0-cycloalkyl-means a cycloalkoxy.

In a preferred aspect, the present invention concerns the preparation of compounds of formula 1, wherein Rs is an alkyl or cycloalkyl and R1, R and A are as defined above.

Also preferred is the process according to the present invention, wherein R 4 is an unsubstituted phenyl or substituted phenyl, and wherein the substituents of the phenyl are one or more selected from the alkyl, halogen or nitro, preferably the methyl or chloro. In a particular preferred aspect of the above process R "is an unsubstituted phenyl and R1, R ~ and A are as defined above and particularly, wherein R3 is an alkyl, preferably methyl.

Particularly preferred is the process, wherein R 4 is a phenyl, R ° is a methyl and R 1, R 2 and A are as defined above.

Also preferred is the process of the present invention, wherein A is an unsubstituted, substituted, or substituted phenylene in which the phenylene substituents which are defined by formula 1 are placed in the ortho, meta or para position. from one to the other. The position for is preferred. The substituted phenylene has one or more additional substituents selected from alkyl, halogen and nitro. Particularly preferred in the above process, wherein A is an unsubstituted phenylene and especially unsubstituted para-phenylene.

Preferred is also the process of the present invention wherein R2 is -O-alkyl, -O-cycloalkyl, -O-aryl, -O-benzyl or -O-aralkyl. Particularly preferred is -O-benzyl and -O-methyl. More preferred is -O-benzyl.

Also preferred is the above process, wherein the hydroboration is carried out as any of the hydroboration reactions which are known in the field such as the achiral or chiral hydroboration reagents. Preferred examples of such compounds are NaBH4 / BF3-Et2? H, BH3-YHF, BH3-dimethylsulfide complex, BHXtriethylamine complex, 9-borabicyclo (3.3.1) -nonano and isopinocampheyl-borane or a chemical equivalent of any of the aforementioned compounds . Particularly preferred is the above process, wherein a compound of formula 2 reacts with NaBH4 / BFj-Et20, BHj-THF or isopinocamfeil borane. More preferably they are NaBH4 / BF3-ETiO and isopinocamfeyl borane.

Compounds of formula 2 and their salts are new and are also part of the present invention.

The preparation of compounds of formula 2 comprises the reaction of compounds of formula 3 or 4. - A R2 OH R 4 With compounds of formula R: -NH_ or a salt thereof, wherein Ri, R_ and A are as described above. Particularly preferred is the preparation of compounds of formula 2 which comprises the reaction of compounds of formula 3 or 4 in the presence of formaldehyde or a chemical equivalent thereof.

Another preferred aspect of the present invention is the isolation of the desired stereoisomer of a compound of formula 1 by crystallization of a salt thereof. Particularly preferred is the crystallization of a chloride of a compound of formula 1.

In addition, a preferred aspect of the present invention is the above process followed by a reaction with hydrogen. Particularly preferred is "the reaction of a compound of formula 1 or a salt thereof, particularly the desired stereoisomer of a compound of formula 1 to a salt thereof with hydrogen and especially in the presence of a catalyst such as palladium carbon.

Another aspect of the present invention is the transformation of (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol hydrochloride to l- [2- [7- [(3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy-phenyl] -piperidin-3-yloxymethyl] -naphthalen-2-yloxy] -ethyl] -4-methyl-piperazine characterized in that: a) The hydrochloride of (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol reacts with hydrogen to produce hydrochloride of (3R, 4R) -4- (4-hydroxy-phenyl) -piperidin-3-ol; b) The reaction with di-tert-butyl-dicarbonate in the presence of a base to form tert-butyl ester of the acid (3R, 4R) -3-hydroxy-4- (4-hydroxy-phenyl) -piperidin-1 -carboxylic; c) Reaction with 1- (3-chloro-propoxymethyl) -2-methoxy-benzene and potassium carbonate to produce tert-butyl ester of (3R, R) -3-hydroxy-4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -piperidine-1-carboxylic acid; d) Reaction with 2-chloromethyl-7- (2-trifluoromethyl) -ethoxymethoxy) -naphthalene and sodium hydride forms tert-butyl ester of the (3R, 4R) -4- [4- [ 3- (2-methox? -benzyloxy) -propoxyl-phenyl] -3- [7- (2-trimethylsilanyl-ethoxymethoxy) -naphthalen-2-ylmethoxy] -piperidine-1-carboxylic acid; e) Reaction-with hydrochloric acid produces tert-butyl ester of (3R, 4R) -3- [7-hydroxy-naphthalene-2-yloxymethyl] -4- [4- [3- (2-methoxy-benzyloxy? ) -propoxy] -phenyl] -piperidine-1-carboxylic acid; f) Reaction with 1- (2-hydroxy-ethyl) -4-methyl-piperazine and triphenylphosphine produces (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) tert-butyl ester) -propoxy] -phenyl] -3- [7- [2- (4-methyl-piperazin-1-yl) -ethoxy] -naphthalen-2-ylmethoxy] -piperidine-1-carboxylic acid, followed by: g) a reaction with hydrochloric acid - 1 - Also preferred is the transformation of (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl-X-piperidin-3-ol to (3R, 4R) -4 hydrochloride - [4- [3- (2-methoxy-benzylaxy) -propoxy] -phenyl] -3- (1, 2, 3, 4-tetrahydro-quinolin-7-yl-ethoxy) -piperidine characterized in that a) The hydrochloride of (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol reacts with hydrogen to produce hydrochloride of (3R, 4R) -4- (4-hydroxy-phenyl) -piperidin-3-o1; b) The reaction with di-tert-butyl-dicarbonate in the presence of a base to form tert-butyl ester of (3R, 4R) -3-hydroxy-4- (4-hydroxy-phenyl) -piperidine-1-carboxylic acid; c) Reaction with 1- (3-chloro-propoxymethyl X2-methoxy-benzene and potassium carbonate to produce tert-butyl ester of (3R, 4R) -3-hydroxy-4- [4- [3- (2 -methoxy-benzyloxy) -propoxy] -phenyl] -piperidine-1-carboxylic acid; d) The reaction with 7-bromomethyl-quinoline hydrobromide and sodium hydride to produce tert-butyl ester of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl acid ] -3- (quinolin-7-yl-methoxy) -piperidine-1-carbaxilic; e) Reaction with hydroborate produces tert-butyl ester of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxyl-phenyl] -3- (1, 2, 3, 4) -tetrahydro-quinolin-7- ^ ylmethoxy) -piperidine-1-carboxylic acid; f) a reaction with hydrochloric acid.

Compounds of formula 1 and their salts are new and also form part of the present invention: 1 R1, R ~ and A are as defined above. A preferred compound is (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol and salts thereof.

Compounds of formula 2 and their salts are new and also form part of the present invention: R, R "and A are as defined above particularly preferred is (R) -4- (4-benzylaxy-phenyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydro-pyridine and you come out of this.

In addition, the compounds of formula 5 and their salts are new and a part of the present invention: Where R1 and A are as defined above and Rβ is still alkyl, cycloalkyl, alkenyl, aryl, aralkyl, aralkoxyalkyl, alkylsulfonyl or arylsulfonyl.

- - Particularly preferred is (R) -4- (4-benzyloxy-phenyl) 1- (1-phenyl-ethyl) iperidine-4-ol and salts thereof.

The invention also discloses the use of a compound of formula 1 in the preparation of renin inhibitors, preferably 1- [2- [7- [(3R, 4R) -4- 4- [3- (2-methoxy-benzyloxy)] -propoxy] -phenyl] -piperidine-3-yloxymethyl] -naphthalen-2-yloxy] -ethyl] -4-methyl-piperazine and (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy ) -propoxy] -fen.yl] -3- (1,2,3,4-tetrahydro-quinolin-7-ylmethoxy) -piperidine, wherein R, R and A are as defined above. ~ In addition, the invention also describes compounds obtained by the above process.

In more detail, the process of the invention can be described as follows: The Hydroboration of a compound of formula 2 and optionally the isolation of the desired stereoisomer: R¿ R 'HX Where R1, R "and A are as defined above and X is an anion, preferably C1-.

A compound of formula 2 can react with compounds which are known for their use in hydrobaration reactions and especially with chiral reagents or achiral hydroboration reagents using inert solvents. Examples for such reagents are BBXTHF, BH _, - dimethylsulfide complex, BH-triethylamine complex and 9-borabicyclo (3.3.1) -nonnate or a chemical equivalent of any of the mentioned compounds. Preferred is isopinocamfeilborane and particularly preferred is NaBH4 / BF3-Et; 0. Also included are the chemical equivalents of any of these compounds. Inert solvents taken alone or in combination can be used, particularly solvents which are known to be used in hydroboration reactions. Examples of such solvents are cyclic or linear ethers such as dimethylether, diethylether, tetrahydrofuran, dioxane, monoglyme, diglyme and mixtures of any of these solvents. A preferred solvent is dimethoxyethane.Jf.

A temperature range of about -20 ° C for the boiling point of the solvent is suitable for the reaction of the present invention. The preferred temperature range is between about -20 ° C to about 20 ° C, preferably from about 0 ° C to about 5 ° C.

The above reaction is followed by an oxidative work under basic conditions including the addition of a base such as NaOH and an oxidizing agent for example perborate or preferably H202.

The temperature range for the addition of the base and the oxidizing agent is about -20 ° C for the boiling point of the solvent. A preferred temperature range for the addition of the base is from about 0 ° C to about 10 ° C and especially from about 5 ° C to about 10 ° C. The reaction mixture is treated with the oxidizing agent preferably at temperatures that are in the range of about 20 ° C to about 60 ° C and particularly 30-50 ° C. However, higher or lower temperatures can be used.

According to the compounds of the above process, formula 1 is formed as a mixture of stereoisomers and particularly as a mixture of diastereomers or only one of the diastereoisomers is formed, in a preferred aspect of the diastereoisomers it is preferably formed.

In one aspect of the present invention, (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydro-pyridine produces a mixture of (3R, 4RX4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol and (3S, 4S) -4- (4-benzyloxy-phenyl) -1- (( R) -1-phenyl-ethyl) -piperidin-3-ol and particularly where the products are formed in a ratio of about 3: 1.

Optionally the desired diastereomer can be isolated by methods known in the art such as chromatography or distillation crystallization. These methods also include the formation of salts or derivatives of compounds of formula 1 and in a second step the separation of these salts or derivatives by crystallization, chromatography or distillation etc. These methods, especially the methods for the separation of diastereomers, are well known in the art and are for example described in Houben-Weyl, Methods of Organic Chemistry.

A preferred method of isolation is the crystallization of salts of compounds 1. Especially preferred acids which can be used for the formation of salts of compounds of formula 1 are, for example, hydrohalic acids, preferably HCl.

Preferred solvents which can be used for the crystallization of compounds of formula 1 and particularly salts of compounds of formula 1 are protic or aprotic solvents which do not react with compounds of formula 1. Especially preferred are ethanol, methanol or their mixtures with pentane or hexane.

A preferred aspect of the isolation of the desired stereoisomer is the crystallization of hydrochlorides of compounds of formula 1, in solvents such as ethanol or isopropanol and particularly in meta o1.

After isolation the desired stereoisomer, especially the diastereomer, can react with hydrogen especially in the presence of a catalyst such as palladium on carbon or any other catalyst which may be suitable in the hydrogenolytic removal of groups such as benzyl. Preferred solvents for this reaction are for example alcohols, water or acetic acid taken alone or in combination. Particularly preferred is the mixture of methanol and water. The compound obtained can then be transformed by the reaction with di-tert-butyl-dicarbonate, preferably in the presence of a base such as triethylamine. A preferred solvent for this reaction is for example methanol. In addition, the compound can be used in the preparation of renin inhibitors as described in WO 97/09311. In general, this preparation can be carried out as follows: The functional functionalization, phenolic can be carried out with alkylation reactions - using benzylic or aliphatic chlorides, bromides, iodides, tosylates or mesylates in the presence of a base such as potassium carbonate in solvents such as an ether, such as tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, acetone, methyl ethyl ketone or pyridine at temperatures between 0 ° C and 140 ° C. The alkylating agents used can either contain the desired whole chain or optionally suitably protected functional groups which also allow structural modifications to a later state of the synthesis.

The functionalization in the secondary hydroxy function of the piperidine ring can then be carried out in solvents such as ethers such as tetrahydrofuran or 1,2-dimethoxy ethane or in dimethylformamide or dimethyl sulfoxide in the presence of a base such as sodium hydride or tert-butoxide. potassium and a suitable alkylating agent, preferably a methyl, aryl, bromide, mesylate or tosylate chloride at a temperature between 0 ° C and 40 ° C. The alkylating agents used can either contain the desired whole substituent or the suitably protected functional groups which also allow structural modifications to a later state of the synthesis. Structural variations may comprise the removal of protective functions followed by functionalizations of the e.g. the etherification of a phenolic radical. But also the reduction of e.g. a unit of quinoline to a tetrahydroquinoline unit per e.g. sodium borohydride, nickel chloride in solvents such as methanol or ethanol A final elimination of the Boc-protective group to be carried out in the presence of hydrochloric, hydrobromic, sulfuric, phosphoric, trifluoroacetic acids in a variety of solvents such as alcohols and mixtures of alcohol / water, chlorinated ethers or hydrocarbons The Boc-protective group can also be determined with anhydrous zinc bromide in inert solvents such as dichloromethane.

The proportion of starting compounds of formula 2 can be presented by the following scheme.

Hal Hal 1 R-Hal A! fc I A? 1 0 OH R l e6 6 7 In detail, a compound of formula 2 can be obtained by the reaction of compound 5 with an acid, e.g. oxalic acid in an inert solvent wherein the compounds 5 are formed by reacting the compound of formula 7 in an inert solvent with butylitol or a Grignard reagent to form an organometallic intermediate which reacts with a compound of formula 8. The preparation of the compound 7 can be carried out by reacting a compound of formula 6 with a compound of formula R-Hal in the presence of a base and preferably a catalyst such as Nal in an inert solvent. Rh is an alkyl, cycloalkyl, alkenyl, aryl, aralkyl, aralkoxyalkyl, alkylsulfonyl or arylsulfonyl. Compound 8 is obtained, for example, by the reaction of RX-NH4 with l-ethyl-l-methyl-4-oxo-piperidinium iodide in the presence of a base. The iodide of 1-ethyl-1-methyl-4-oxo-piperidino is obtained by the reaction of 1-ethyl-4-piperidone with methyl iodide in an inert solvent.

Alternatively, a compound of formula 2 can be obtained by the reaction of an ammonium salt R'-NH / X-with formaldehyde and a compound 3 which can. obtain e.g. by a reaction of the appropriate phosphorane with a compound 9 in an inert solvent. ~ Alternatively, a compound 2 can be prepared by the reaction of an ammonium salt of formula R: -NH / X-with formaldehyde and with a compound of formula 4. A compound 4 is formed by the reaction of an organometallic compound containing a methyl group linked to the metal with a methylmagnesium bromide or methylthio- with a compound 9, while the compound 4, wherein R ~ means chlorine, bromine or iodine can be prepared via oxidation of a halocumene (for example described in US Pat. 3954876 or DE 2302751). 0 Alternatively, the compounds of formula 2 are obtained by reacting a salt of formula R 1 -NH .- * - X with formaldehyde and a compound 4. Preferably, R -NH, X is generated in the reaction mixture of a compound R ! -NH using the appropriate amount of a suitable HX acid. In addition, compound 4 can be obtained by the reaction of a compound 11 with a suitable organometallic compound. In addition, compound 11 is formed by the reaction of a compound 10 with Rh-X in the presence of a base in an inert solvent R 'is as defined above.

The following preparations and examples illustrate preferred aspects of the present invention but do not attempt to limit the scope of the invention.

Example 1 _ __ (Preparation of the product; a) Preparation of (3R, R) -4- (4-benaloxy-phenyl) -1- (R) -1-phenyl-ethyl) -piperidin-3-ol. __ _ ___ The reaction flask is charged under an argon atmosphere with 60 g (162 mmol) of (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1, 2, 3, 6 -tetrahydro-pyridine and 600 ml of dimethoxyethane. After 9.2 g (243 mmol) of sodium borohydride is added, the mixture is cooled to 0 ° C under stirring. Then 45.9 g (323 mmol) of boron trifluoride diethyl ether is added over 40 minutes, where the temperature is maintained at 0-5 ° C. The reaction mixture is stirred at 5 ° C for an additional 2 hours and then at room temperature for 165 minutes. After cooling to 0 ° C, 350 ml of NaO? 4N is added during 1 Jhora, where the temperature is maintained at 0-5 ° C. Then 60 ml of H_0¿ at 301 is added at 20 ° C for 1 hour. After further stirring for 20 minutes the mixture is heated to 45 ° C, which causes the temperature to rise temporarily to 53 ° C. After cooling, the temperature is maintained at 45 ° C for a total of 3 hours. After stirring overnight at room temperature the reaction mixture is poured into a mixture of 1 L of a solution of half saturated NaCl and 800 ml of ethyl acetate. After extraction with ethyl acetate in the phases > Organic extracts are washed with water and dried with Na. SW,. Then 67.4 g of the diastereomeric mixture of (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol and (3S, 4S) are concentrated. ) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol is obtained in an erroneous ratio of 3: 1. b) Isolation of (3R [beta] R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-lo hydrochloride. ml of 37 ° HCl are added for more than 30 minutes to 80 ml of ethanol at 5 ° C. This mixture is added under stirring at 15 ° C for 1 hour to a solution of 61. Aq of product of the mixture obtained by reaction a) in 300 ml of ethyl acetate. The crystals begin to form after the addition of 1/3 of the previous ethanolic / HCl solution. The mixture is stirred for 4 hours at 0 ° C and then 100 ml of pentane is added and the stirring is continued for 1 hour at 0 ° C. The crystals are separated, washed with pentane (2x50 ml) and dried under vacuum. 61.5 g of crude hydrochlorides of the diastereomeric alcohols are obtained. The hydrochlorides are dissolved at 60 ° C in 260 ml of methanol and are crystallized overnight under agitation and cooled below room temperature. The crystals are separated, washed with ethanol (2x50 ml) and pentane (2x80 ml) and dried in vacuum 38.3 g of (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R ) -1-phenyl-ethyl) -piperidin-3-ol are obtained as white crystals.

Example 2 [Product preparation] a) Preparation of (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol.

The reaction flask is charged under an argon atmosphere with 4 ml of a 0.75 M solution of isopinocampheyl-borane (I-BH-derivative of (+) - -pinene) in THF. 1 mmol of (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydro-pyridine is added and the mixture is stirred for 16 hours at 22 ° C. The embodiment of the reaction mixture includes a treatment with acetaldehyde and alkaline H ^ 0 and is carried out in analogy to the method described by H.C. Brown et al (J. Org. Chem 1987, 52, 310) for this type of hydroboration. Chromatography of the crude product provides 240 mg of a mixture of (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-y and (3S , S) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol in a ratio of 85:15. b) The separation of the desired stereoisomer can be carried out as described in example Ib).

Example 3 [Preparation of the starting material) a) Preparation of 4-benzyloxybromobenzene 200 g (1.16 mol) of 4-bromophenol are dissolved in 2.1 liters of acetone under an argon atmosphere. Then 320 g (2.31 mol) of K_CO., And 3.465 g (23.1 mmol) of Nal are added. The mixture is stirred at room temperature and 292.7 g (2.31 mol) of benzyl chloride are added during 1 hour. The mixture is then boiled for 48 hours. The acetone (ca. 500 ml) is partially removed in the rotary evaporator. 1.2 L of aqueous Na_C0j at 10 ° are added to the residue. After extraction with ethyl acetate (lxl L + 2x500 ml) the organic phase is washed with 1 L of a saturated NaCl solution. After drying with Na ^ SQ and concentrating the main part of the benzyl chloride, it is removed. 400 ml of pentane are added to the residue. Crystallization begins during stirring at 0 ° C. The crystals are separated and washed with 2x150 ml of pentane and dried for 2 hours at 15 mbar (40 ° C bath temperature) and 2 hours under high vacuum at room temperature. 230 g (75 °) of 4-benzyloxybromobenzene are obtained. b) Preparation of iodide of 1-methyl-4-oxo-piperidinium.

To a solution of 93 g (730 mmol) l-ethyl-4-piperidone (Aldrich 27950-1) in 730 ml of acetone, 124 g (876 mmol) of methyl iodide (Acros 12237) are added over 30 minutes. The temperature is maintained at 25-30 ° C. The product begins to precipitate after the addition of 1/5 of methyl iodide. The mixture is stirred for 5 hours at 22 ° C and 30 minutes at 0 ° C. The cold suspension is filtered and the product is washed with acetone. 1.88 g (95X of l-ethyl-1-methyl-4-oxo-piperidinium iodide are obtained. c) Preparation of (R) -1- (1-phenyl-ethyl) -piperidin-4-one.

Under an argon atmosphere 84.6 g (698 mmol) of (R) - (+) - 1-phenylethylamine (Merck No. 807031) and 1.4 L of ethanol are mixed. A solution of 203 g. (1.47 mol) of K_C0., In water is added. The mixture is heated to 80 ° C under stirring and a solution of 1.88 g (698 mmol) of 1-ethyl-1-methyl-4-oxo-piperidinium iodide in 700 ml of water are added for 1 hour. The mixture is heated again for 105 minutes under stirring and then the ethanol is removed in the rotary evaporator.

The residue is extracted with dichloromethane (1x1.5 L + 1x1 L). The organic phases are washed with a solution of half saturated NaCl (2x800 ml) and dried with Na_S0-.. After evaporation of the solvent 144 g of crude (R) -1- (1-phenyl-ethyl) -piperidin-4-one are obtained. 70 ml of 37% HCl are added at 5 ° C to 300 ml of isopropanol for 30 minutes. The mixture is added for 2 hours under stirring at 15-20 ° C to a solution of 144 g of (R) -1- (1-phenyl-ethyl) -piperidin-4-one in 100 ml of ethyl acetate. The crystallization begins after the addition of 1/3 of the previous mixture. The suspension is stirred overnight at room temperature and then for 3 hours at 0 ° C. After 80 ml of pentane is added to the mixture, stir again for 3 hours at 0 ° C. The product is separated and washed with isopropanol (3x70 ml). After drying the hydrochloride (188 g), it is suspended in 1 L of diclarome anc and 700 ml of Na_CO_- to 10"are added.The organic phase is separated and washed with a solution of half saturated NaCl Xxl L). The organic phase is concentrated with MgSO- The residue is dried for 2 hours in a high vacuum to give 113 g of (R) -1- (1-phenylethyl) -piperidin-4-one. d) Preparation _ __ of (R) -4- (4-benzyloxyl-phenyl) -1- (1-phenyl-ethyl) -piperidin-4-ol.

Under an argon atmosphere 175.2g (666 mmol) of 4-benzyloxybromobenzene are dissolved in 1.4 L of dry THF (MS 4 A). The solution is cooled to -75 ° C and a solution of 416 ml of butylithium 1.6 M (666 mmol) in hexane are added over 40 min. After stirring for 1 hour a solution of 113 g (555 mmol) of (R) -1- (1-phenyl- = ethyl) -piperidm-4-one in 400 ml of dry THF are added for 1 hour to -75. ° C. The mixture is stirred for another hour, after heating to room temperature, it is poured into 1.5 L in an ice bath. The mixture is extracted with 1 L of ethyl acetate. The organic phase is washed with 1 L of a solution of half saturated NaCl, dried with Na_SO, and concentrated. In this manner, 262 g of (R) -4- (4-benzyl-loxi-phenyl) -1- (1-phenyl-ethyl) -piperidin-4-ol are obtained. e) Preparation of (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydropyridine. _ 121. 7 g of crude (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -piperidin-4-ol are dissolved at 40 ° C in 1.21 L of dichloroethane. 59.4 g (471 mmol) of oxalic acid (Merck 492) are added. The mixture boils for 3 hours, until 20 ml of water are separated. The reaction mixture is washed at room temperature with 1.2 L of Na_CO_, at 10X The precipitate (52 g) is separated from the filtrate ~ A and added to a mixture of 250 ml of 2N NaOH and 300 ml of dichloromethane, where it is dissolved after stirring for 30 min at a temperature of 30-35 ° C. The organic phase is separated and washed with a solution of half saturated NaCl. The precipitate obtained is separated and dissolved in 200 ml of dichloromethane and 60 ml of methanol. The combined organic phases are concentrated after drying with NaSO 2. 80 ml of ethyl acetate are added to the residue and stirred for 2 hours. The crystals are separated, washed with pentane and dried. 36.5 g of (R) -4- (4-benzyloxy-phenyl-1- (1-phenyl-ethyl) -1,2,3,6-tetrahydropyridine are obtained.

The organic phase of the aforementioned filtrate A is washed with 1.5 L of a medium saturated NaCl solution. After drying the organic phase is concentrated. 80 ml of ethyl acetate and 30 ml of ether are added to the residue. After stirring for 3 hours at 0 ° C the crystals are separated and then washed with ethyl acetate (2 × 20 ml) and pentane (50 ml) and dried. In this way, 33.0 g of (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydropyridine are obtained.

In total: 33.0 g + 36.5 g = 69.5 g of (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1, 2, 3, 6-tetrahydropyridine is obtained (73 ° C) based on (R) -l- (1-phenyl-ethyl) -piperidin-4-on).

Example 4 (Preparation of the starting material) a) Preparation of 2- (4-benzyloxy-phenyl) -propen-2 -30- At room temperature, 29.6 g of methylphosphine (83 mm3) are suspended in tetrahydrofuran, a solution of 9.2 g of tert-butyroxyane potassium (82 ml in 35 ml of tetrahydrofuran). add for more than 30 minutes, and the mixture is stirred for XC minutes at a warm temperature and then it is cooled to 0 ° C. - This temperature, a solution of 1X0 s to 4-benzyl, acetophenone (75 mmol) in 100 ml of tetrahydrofuran are added for 1.5 hours to the solution of the product • The stirring at 0 ° C is continued for 1 hour, then 1 ml of acetic acid are added to the reaction mixture. one ezc to 300 ml of an aqueous solution of saturated sodium bicarbonate, 200 g of ice and 250 ml of ethyl acetate The aqueous phase is then extracted with ethyl acetate.The organic phases are washed with 200 ml of an aqueous solution of sodium chloride at 20, combined, dry (Na SO) and evaporated under reduced pressure to give 40.5 g of a white solid residue. The residue is suspended in 250 ml of hexane, and the mixture is stirred overnight at room temperature. The tp-phenylphosphmoxide is filtered and washed with hexane. The filtrate is evaporated to give 15.8 g of a white solid. To remove traces of the trifemlfosfma oxide, the product is passed through a pad of silica gel using 95: 5 hexane-ethyl acetate (750 ml) as eluent. The combined fractions containing the desired compound are evaporated. The residue is suspended in 80 ml of pentane, then the product is collected by filtration, washed with pentane and dried at constant weight. Obtaining 14.1 g of 2- (4-benzyloxy-phenyl) -propen ^ 2. b) Preparation of (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-1-ethyl) -1,2,3,6-tetrahydro-pyridine. __ At room temperature 20.7 g of (R) -1-phenylethylamine hydrochloride (131 mmol) are dissolved in 60 ml of water. 22 ml of 36.5 ° aqueous formaldehyde is added and the mixture is stirred for 10 minutes at room temperature and then warmed to 40 ° C. At this temperature, a solution of 26.75 g of 2- (4-benzyloxy-phenyl) -propen-2 (119 mmol) in a mixture of 30 ml of dioxane and 74 ml of dichloromethane are continuously added "for more than 1.25 hours. During and after the addition of the olefin solution, the dichloromethane is distilled, after removing the dichloromethane, the reaction mixture is stirred at 70 ° C overnight.A solution of 9.96 g of concentrated sulfuric acid (99 mmol) in 30 ml of water are added for 5 min to the reaction mixture which is heated to a temperature of 95-100 ° C and stirred at this temperature for 5.5 hours.The reaction mixture is poured slowly into a mixture of 250 ml of an aqueous solution of sodium carbonate at 10, and ice and then extracted with 600 ml of dichloromethane.The organic phases are extracted with a 600 ml portion of 20% aqueous sodium chloride, combined and dried with (Na- .S04) and evaporated under reduced pressure to give 64 g of crude product as an oil. red coffee which partially crystallizes. The crude product is dissolved in 250 ml of dichloromethane. 120 ml of isopropanol are added and the dichloromethane and a small portion of isopropanol are distilled under reduced pressure (rotary evaporator, bath at 45 ° C). White crystals begin to precipitate and the suspension is stirred at 0 ° C for 2 hours. The crystals are collected on a funnel filter and washed with three 50 ml portions of cold isopropanol and 60 ml of hexane. In this way 29.2 g (66%) of (R) -4- (4-benzyloxy-n-nyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydropyridine are obtained after drying by 2 hours at 16 mbar at a temperature of 50 ° C and for 2 hours at 0.2 mbar at a temperature of 22 ° C.

Example 5 __ _, _, ___ "(Preparation of the start material) a) Preparation of 2- (4-benzyloxy-phenyl) -propan-2-ol.

The reaction flask is charged under an argon atmosphere with 3.45 g of magnesium (142 mmol). A solution of 21.16 g of methyl iodide (147 mmol) in 120 ml of tert-butyl methyl ether are added over 45 minutes at 45 ° C under stirring. Stirring is continued for 1 hour at 45 ° C and then a solution of 27.12 g of 4-benzyloxyacetophenone (120 mmol) in 100 ml of tetrahydrofuran is added over 45 minutes, again maintaining the temperature at 45 ° C. Stirring at 45 ° C continued for 1.5 hours. After cooling to room temperature, the white suspension is poured into a mixture of 100 ml of a 10% aqueous solution of ammonium chloride and ice and extracted with 100 ml of ethyl acetate. The aqueous phase is separated and extracted with 100 ml of ethyl acetate. The organic phase is washed with 120 ml of an aqueous 20% sodium chloride solution, combined, dried (MgSO) and evaporated under reduced pressure to obtain 29.9 g of crude product as an oil which partially crystallizes. It is taken up in 30 ml of dichloromethane.The solution is concentrated on the rotary evaporator almost to dry, then 6 ml of ethyl acetate are added followed by the gradual addition of a total of 180 ml of hexane.The suspension is then kept at 0 ° C. C for 30 minutes The crystals are collected and washed with cold hexane, after drying for 2 hours at 16 mbar and at a temperature of 45 ° C, 26.7 g (92) of 2- (4-benzyloxy-phenyl) are obtained. -propan-2-ol B) Preparation of (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydropyridine. ~ At room temperature 6.94 g of (R) -1-phenylethylamine hydrochloride (44 mol) are dissolved in 24 ml of water. 8.0 g of 36.5% aqueous formaldehyde (2.92 g of HCHO, 97 mmol) are added and the mixture is stirred for 10 minutes. Then, to a solution of 9.68 g of 2- (4-benzyloxy-phenyl) -propan-2-ol (40 mmol) in 10 ml of dioxane are added. The reaction mixture is heated to 70 ° C and stirred overnight at this temperature. A solution of 1.72 g of concentrated sulfuric acid (17.6 mmol) in 8 ml of water is added to the reaction mixture in 5 minutes. The mixture is then heated to 100 ° C and stirred at this temperature for 7 hours. The reaction mixture is slowly poured into a mixture of 150 ml of an aqueous 10% sodium carbonate solution and 50 g of ice are extracted with 450 ml of dichloromethane.The organic phases are extracted with 150 ml of water, combine, dry (NaSO 4) and evaporate under reduced pressure to give 18.1 g of crude product as an orange-red oil which partially crystallizes.

The crude product is dissolved in 60 ml of dichloromethane. 80 ml of isopropanol are added and the dichloromethane and a small portion of the Xsopropanol are distilled at 400 mbar (rotary evaporator, 55 ° C). The white crystals precipitate and the suspension is stirred for 1 hour at room temperature and additionally for 1 hour at 5 ° C. The crystals are collected and washed with 2 portions of 25 ml of isopropanal and with 2 portions of 25 ml of hexane. The product is then dried for 2 hours at 16 mbar and at a temperature of 40 ° C and for 3 hours at 0.2 mbar at a temperature of 22 ° C. In this way 9.1g (61%) (R) -4 are obtained. - (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydropyridine.

Preparation of (R) -l-phenylethylamine hydrochloride.

At room temperature 122 g of (R) -1-phenylethylamine (1.0 mol) are dissolved in 30 ml of isopropanol. The solution is stirred and cooled to 0 ° C. Then, a previously prepared solution of 100 ml of 37% hydrochloric acid (118 g, 1.2 mol) in 320 ml of isopropanol are added for 1 hour. The solution is stirred at 0 ° C for an additional 40 minutes, and then concentrated in a rotary evaporator (at 16 mbar, bath at 45 ° C) for a volume of 300 ml. The translucent gel that forms is transferred to a 1.5 L flask, then, under agitation, 250_ ml of tert-butyl methyl ether, is slowly added. The crystals begin to form and the suspension is stirred at 0 ° C for 3 hours. The product is collected by filtration, washed with 100 ml of tert.butyl methyl ether and dried at 30 ° C and 16 mbar for 4 hours. In this way 133 g (84%) of 1-phenylethylamine hydrochloride are obtained.

Example 6 __ ._ (Preparation of the starting material) a) Preparation of methyl-4-benzyloxybenzoate To a solution of 15.2 g of methyl-4-hydroxybenzoate (100 mmol) in 125 ml of N, N-dimethylformamide are added with stirring 33.13 g of potassium carbonate (240 mmol).

Then 17.45 g of benzyl bromide (102 mmol) are added in 5 minutes. The mixture is stirred at 25 ° C using a water bath. The reaction is complete after 3 hours. The reaction mixture was poured into a mixture of 180 g of ice and 200 ml of ethyl acetate. After extraction, the aqueous phase is separated and extracted with three 80 ml portions of ethyl acetate. The organic phase is washed with 2 portions of 150 ml of water, combined, dried with (MgSO and particularly concentrated to give a slurry.) 60 ml of pentane are added and the suspension is stirred for 2 hours at room temperature. The crystalline methyl-4-benzyloxybenzoate is collected on a filter, washed with pentane and dried. b) Preparation of 2- (4-benzyloxy-phenyl) -propan-2-ol.

Under an argon atmosphere 6.63 g of magnesium (273 mmol) are suspended in 15 ml of tert-butyl methyl ether. A solution of 38.68 g of methyl iodide (273 mmol) in 145 ml of tert-butyl methyl ether are added during 45 minutes under stirring and maintaining the temperature at 40 ° C. The stirring is then continued at 40 ° C for 1.5 hours and then the mixture is cooled to room temperature. A solution of 30.0 g of methyl-4-benzyloxybenzoate (124 mmol) in 120 ml of tetrahydrofuran is then added for 1 hour. The temperature is maintained at 20 ° C. After the addition is complete, the reaction mixture is heated to 42 ° C and stirred for 3 hours at this temperature. After cooling to room temperature, the reaction mixture is poured into a mixture of 300 ml of an aqueous solution of 10% ammonium chloride and 100 g of ice and extracted with ethyl acetate. The organic phases are washed with water and aqueous sodium bicarbonate -saturated, combined, dried and evaporated to give the crude product as oil which partially crystallizes. The product is dissolved at 25 ° C in diethyl ether. When the crystals begin to separate, the solution is cooled to 18 ° C. After 30 minutes hexane is added. The suspension is then stirred for 1 hour at 5 ° C. The crystalline 3- (4-benzyloxy-phenyl) -propan-2-ol is obtained which is collected on a filter and washed with hexane. c) Preparation of (R) -4- (4-benzyl-phenyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydropyridine. _ Z ~ _ _ X At room temperature, the reaction flask is charged with 10.66 g of (R) -1-phenylethylamine (88 mmol) and 40 ml of water. Under stirring, the pH of the mixture is adjusted to the value of 4.1 by slowly adding a solution of hydrochloric acid. Then 16.0 g of 36.5% aqueous formaldehyde (5.84 g of HCHO, 194 mmol) are added and the mixture is stirred for 10 minutes. A solution of 19.38 g of 2- (4-benzyloxy-phenyl) -propan-2-ol (80 mmol in 20 ml of dioxane) is then added. The reaction mixture is heated to 70 ° C and stirred overnight at this temperature. A solution of 3.44 g of concentrated sulfuric acid (35 mmol) in 16 ml of water is added over 5 minutes to the reaction mixture which has then been heated to 100 ° C and stirred at this temperature for 7 hours. The reaction mixture is poured slowly into a mixture of 300 ml of 10% aqueous sodium carbonate and 100 g of ice and extracted with dichloromethane. The organic phases are extracted with water, combined, dried and evaporated to obtain an orange-red oil which partially crystallizes. The crude product is dissolved in 120 ml of dichloromethane. 160 ml of isopropanol are added and the dichloromethane and a portion of the isopropanol are distilled at 400 mbar (in a rotary evaporator, bath at 55 ° C). The white crystals precipitate. The crystals are collected on a funnel filter and washed with isopropanol and then with hexane. The obtained (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1,2,3,6-tetrahydropyridine is then dried for 2 hours at 16 mbar and a temperature of 40 °. C and for 3 hours at 0.2 mbar and a temperature of 22 ° C.

Example 7 ___ (Preparation of a precursor for renin inhibitors) a) Preparation _ of hydrochloride. of (3R, R) -4- (4-hydroxy-phenyl) -piperidin-3-ol.

The reaction flask is charged under an argon atmosphere with 250 mg of 10% palladium-carbon (Degussa E-101 N / D), then a solution of 5 g (11.8 mmol) of (3R, R) -4- (4-hydroxy-phenyl) -piperidin-3-ol in 50 ml of methanol and 5 - 4! ml of water are added. After the hydrogenation- for 6 hours at room temperature and to the ester. The catalyst is then separated by filtration and washed ccr. methanol The filtrate is concentrated and the remaining water is removed azeotropically in the rotary evaporator using toluene (3x100 ml). In this manner £ X g of 3R.4R hydrochloride X4-hydt > v '' - fer.il) -piper? dm-3-ol as crystals. whites. b) Preparation of tert-butyl ester of (3R, 4R ^ -3-hydroxy-4- (4-hydroxy-phenyl) -piperidine-1-carboxyl co. 2. 5 g of (33.4P ^ -4- (4-hydroxy-phenyl) -piperidm-3-ol hydrochloride are dissolved in 33 ml of methanol, then 2.3 g of triethylamine are added and the mixture is cooled to -18 ° C. A solution of 2.6 g (11.9 mmol) of di-tert-butyl-dicarbonate in 16 ml of methanol are added over 30 minutes. The reaction mixture is stirred for 1 hour at -18 ° C. and then heat slowly to 0 ° C. After stirring for an additional 2 hours at 0 ° C. add 10 ml of water and remove the methanol with the rotary evaporator.The residue is dissolved in a mixture of dichloromethane / water and a solution of NaHSO The organic phase is washed with a solution of NaHCOj and with a solution of saturated NaCl, the organic phase is extracted twice with dichloromethane.The crude product is obtained after drying with MgSO4) and concentrate the organic phases, then the diethyl ether is added and the product begins to crystallize. The pentane mixture is placed in the refrigerator. The next day the crystals are separated, washed with pentane and dried in vacuo. 3.1 g of (3R, 4R) -3-hydroxy-4- (4-hydroxy-phenyl) -piperidine-1-carboxylic acid tert-butyl ester are obtained as white crystals.

Example 8 _- _ - ____ Preparation of 1- [2- [7- [(3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -piperidin-3-yloxymethyl] -naphthalene-2- iloxy] -ethoxy] -4-methyl] -piperazine. _ a) A solution of 16.50 g (56.24 mmol) of (3R, 4R) -3-hydroxy-4- (4-hydroxy-phenyl) -piperidine-1-carboxylic acid terbutyl ester in 40 ml of dimethylformamide is treated in succession with 12.68 g (59.06 mmol) of l- (3-chloro-propoxymethyl) 2-methoxy-benzene (WO 97/09311) and 12.44 g (89.99 mmol) of potassium carbonate. This mixture is stirred at 120 ° C for 26 hours. Subsequently, it is filtered, concentrated to a few millimeters, poured into 30 ml of an ice / water mixture and extracted three times with 100 ml of methylene chloride each time. The combined organic phases are washed once with a small amount of water, dried with magnesium sulfate, evaporated under reduced pressure and dried under high vacuum. In this way, (31.64 g) of crude product is obtained which is separated on silica gel using a 99: | of methylene chloride and methanol as the eluent yielding 25.4 g (95.8% theory) of tert-butyl ester of (3R, 4R) -3-hydroxy-4- [4- [3- (2-methoxy-benzyloxy) ) -propoxy] -phenyl] -piperidine-1-carboxylic acid as a light yellow oil; MS: 489 (M + NHX. b) 25.4 g (53.86 mmol) of (3R, 4R) -3-hydroxy-4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -piperidine-tert-butyl ester 1-carboxylic acid and 17.78 g (55.06 mmol) of 2-chloromethyl-7- (2-trimethylsilanyl-ethoxymethoxy) -naphthalene (WO 97/09311) are dissolved in 180 ml of dimethylformamide under one atmosphere of argon and then 2.49 g (57.09 g. mmol) of a dispersion of sodium hydride (55% in mineral oil) are added. Subsequently, the mixture is stirred at room temperature for 5 hours. The reaction mixture is poured into ice water, the product is extracted 3 times with methylene chloride, the organic phases are washed twice with distilled water, then dried with magnesium sulfate, filtered and concentrated under a water jet vacuum. In this way, the gel was chromatographed on silica gel with methylene chloride and methanol to the crude product. In this way 36.43 g are obtained (89.2% theory) of tert-butyl ester of (3R, 4R) -3-hydroxy-4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- [7- (2-trimethylsilanyl-ethoxymethoxy) -naphthalen-2-ylmethoxy] -piperidine-1-carboxylic acid as a yellow oil MS: 759 (M + H) *. c) 36.43 g (48.06 mmol) tert-butyl ester of (3R, 4R) -3-hydroxy-4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- [ 7- (2-trimethylsilanyl-ethoxymethoxy) -naphthalen-2-ylmethoxy] -piperidine-1-carboxylic acid are placed in 700 ml of pure methanol at 0 ° C, then 48 ml (96.1 mmol) of hydrochloric acid in methanol (2.0 molar) ) is added dropwise at 5 ° C maximum and then the mixture is warmed to room temperature. After 120 minutes the reaction mixture is poured into an ice-cold sodium hydrogen carbonate solution and the product is extracted three times with methylene chloride. The organic phases are washed once with distilled water, dried with magnesium sulfate, filtered and concentrated in a water-jet vacuum The crude product thus obtained is chromatographed on silica gel with methylene chloride and methanol. In this way, 28.06 g (93% theory) of the tert-butyl ester of (3R, 4R) -3- [7-hydroxy-naphthalen-2-yloxymethyl] -4- [4- [3- ( 2-methoxy-benzyloxy) -propoxy-phenyl] -piperidine-1-carboxylic acid as a light yellow amorphous solid, MS: 645 (M + NH 4 +). d) A mixture of 10.15 g (16.17 mmol) of (3R, 4R) -3- [7-hydroxy-naphthalen-2-yloxymethyl] -4- [4- [3- (2-methoxy) tert-butyl ester) -benzyloxy) -propoxy-phenyl] -piperidine-1-carboxylic acid 2.80 g (19.42 mmol) of 1- (2-hydroxy-ethyl) -4-methyl-piperazine [J. Pharm. Sci. (196S), 57 f3), 384-9] and 5.51 g (21.01 mmol) of triphenylphosphine are dissolved in 450 ml of tetrahydrofuran. Then a solution of 4.75 g (20.22 mmol) of di-tert-butyl azodicarboxylate in 50 ml of tetrahydrofuran is slowly added to the reaction mixture at 0 ° C and stirred continuously for 2 hours at room temperature. The reaction mixture is in a water jet vacuum. The crude product obtained in this way is chromatographed on silica gel with methylene chloride and methanol. In this way 9.18 g (75.3% theory) of the tert-butyl ester of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- acid are obtained. [7- [2- (4-methy1-piperazin-1-yl) -ethoxy] -naphthalen-2-ylmethoxy] -piperidine-1-carboxylic acid as a colorful oil; MS: 754 (M + H) 4. e) A solution of 9.15 g (12.14 mmol) of tert-butyl ester of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- [7] - [2- (4-Methyl-piperazin-1-yl) -ethoxy] -naphthalen-2-ylmethoxy] -piperidine-1-carboxylic acid in 250 ml of methanol is treated at room temperature with 36.41 ml of a sodium chloride solution. 2.0 M hydrogen in methanol and the mixture is stirred at 50 ° C for 4 hours. Subsequently, the solution is evaporated under reduced pressure and the residue is partitioned between 200 ml of a saturated sodium carbonate solution and 150 ml of methylene chloride. The aqueous phase is extracted once more twice with 100 ml of methylene chloride; then the organic phases are combined, dried with sodium sulfate and evaporated under reduced pressure. For purification, the crude product was chromatographed on silica gel using a 90:10 mixture of methylene chloride and methanol as the eluent. In this way 5.25 g (66% theory) of l- [2- [7- [(3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -prspoxy] -phenyl] are obtained. -piperidin-3-yloxymethyl] -naphthalen-2-yloxy] -ethyl] -4-methyl-piperazine as an amorphous and colorful solid; MS: 65 (M + H) Example 9 Preparation of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- (1,2,3, -tetrahydro-quinolin-7-ylmethoxy) -piperidine . _. _____ a) 3.40 g (7.20 mmol) of (3R, 4R) -3-hydroxy-4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -piperidine-1-carboxylic acid ester and 2.18 g (7.20 mmol) of 7-bromomethyl-quinoline hydrobromide (1: 1) fJ.Am. Chem. Soc. 7_7. 1054 (1955)], are dissolved in 50 ml of pure dimethylformamide under an argon atmosphere and then 0.83 g (19.0 mmol) of a sodium hydride dispersion (55% in mineral oil) is added at room temperature in small portions. Subsequently, the mixture is stirred at room temperature for 16 hours. The reaction mixture is poured into ice water, the product is extracted 3 times with ethyl acetate, the combined organic phases are washed twice with distilled water, then dried with magnesium sulfate, filtered and concentrated. The crude product (5.2 g of a yellow oil) is chromatographed on silica gel with ethyl acetate / hexane in a ratio of 2: 1 to yield 3.77 g (85.4% theory) of tert-butyl ester of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- (quinolin-7-yl-methoxy) -piperidine-1-carboxylic acid as a colorful oil; MS: 613 (M + HXb) 3.77 g (6.15 mmol) tert-b-using ester of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- (quinoline- 7-yl-methoxy) -piperidine-1-carboxylic acid and 0.93 g (3.12 mmol) of nickel (II) chloride hexahydrate are dissolved in 50 ml of methanol, 0.93 g (24.8 mmol) of sodium borohydride are added at 0 ° C in small portions for a period of more than 30 minutes. The resulting black suspension is stirred for 1 hour at 0 ° C, and 2 hours at room temperature. The reaction mixture is poured slowly into a vigorously stirred mixture of 150 ml of a 5% solution of ammonium chloride and 400 ml of ether. After stirring for 30 minutes, the organic phase is separated. The light blue aqueous phase is extracted 5 times with ether. The combined organic phases are washed twice with distilled water, then dried with magnesium sulfate, filtered and concentrated. The crude product (3.2 g of a yellow oil) is chromatographed on silica gel with ethyl acetate / hexane in a 1: 1 ratio to yield 2.92 g (76.9% theory) of tert-butyl ester of (3R, 4R) acid ) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- (1, 2, 3, 4-tetrahydro-quinolin-7-ylmethoxy) -piperidine-1-carboxylic acid as a colorful oil; MS: 617 (M + H) +. c) 2.92 g (4.73 mmol) of tert-butyl ester of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -3- (1, 2, 3, 4-tetrahydro-quinolin-7-ylmethoxy) -piperidine-1-carboxylic acid are dissolved in 63 ml of pure methanol, then 63 ml (126 mmol) of hydrochloric acid in methanol (2.0 molar) are added at room temperature. After stirring for 150 minutes at 50 ° C, the reaction mixture is poured into 150 ml of a 5% ice cold sodium hydrogencarbonate solution and the product is extracted five times with 100 ml of methylene chloride. The combined organic phases are washed twice with 50 ml of distilled water, dried over magnesium sulfate, filtered and concentrated The crude product (2.9 g of a yellow oil) is chromatographed on silica gel with a solution of sodium chloride. methylene / methanol / 28% ammonium hydroxide in a ratio of 14: 1: 0.1 V / V / V to - - produce 1.90 g (77.7% theory) of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -3- (1, 2, 3, 4-tetrahydro-quinolin-7-ylmethoxy) -piperidine as a light yellow resin, MS: 517 (M + H) +.

It is noted that in relation to this date, the best method known to the applicant, to carry out the aforementioned invention is that it is clear from the present description of the invention. __ Having described the invention as an antecedent, the content of the following is claimed as property:

Claims (18)

1. A process for the preparation of a compound of formula 1 or a salt thereof characterized in that the process comprises a) the hydroboration of a compound of formula 2 2 in such formula; A is arylene; R1 is -C * R3R4R5; R ~ is an -O-alkyl, -O-cyclyl; -O-alkenyl, -O-aryl, -O-aralkyl, -O-aralksxyalkyl, -O-alkylsulfonyl, -O-arylsulfonyl, chlorine, bromine or iodine; R3 hydrogen; R is an aryl; R5 is an alkyl, cyclyl, aryl, alkoxyalkyl or hydroxyalkyl; And C * is an asymmetric carbon atom. b) optionally followed by isolation of the desired stereoisomer.

2. The process according to claim 1, characterized in that Rr is alkyl or cyclyl.

3. The process according to claim 1 or 2, characterized in that R ^ is phenyl which is optionally substituted by one or more groups independently selected from alkyl, halogen or nitro.

4. The process according to any of claims 1 to 3, characterized in that R "is phenyl and R5 is methyl.

5. The process according to any of claims 1 to 4, characterized in that A is phenylene and, wherein the phenylene is optionally substituted by one to four additional substituents independently selected from alkyl, halogen or nitro.

6. The process according to any of claims 1 to 5, characterized in that R "is -0-benzyl or -0-methyl.

7. The process according to any of claims 1 to 6, characterized in that a compound of the formula 2 reacts with NaBHl / BFj-EtX BH.-THF or isopinocamfeyl borane.

8. The process according to any of claims 1 to 7, characterized in that a compound of formula 2 is prepared by a process which comprises reacting a compound of formula 3 or formula 4-A R 3 OH A R 02 4 with a compound of the formula R1-NH2 or a salt thereof and wherein R1, R2 and A are as defined in claim 1.

9. The process according to any of claims 1 to 8, characterized in that the desired stereoisomer of a compound of formula 1 is isolated by crystallization of a salt thereof.

10. The process according to any of claims 1 to 9, characterized in that it is followed by the reaction with hydrogen.

11. A process according to any of claims 1 to 10, wherein a compound of formula 1 is converted to 1- [2- [7- [(3R, R) -4- [4- [3- ( 2-methoxy-benzyloxy) -propoxy] -phenyl] -piperidin-3-yloxymethyl] -naphthalen-2-yloxy] -ethyl] -4-methyl-piperazine characterized in that a) (3R, 4R) -4- (4-benzyloxy? -phenyl) -1- ((R) -1-phenyl-ethyl) -piperidin-3-ol hydrochloride reacts with hydrogen to produce (3R) hydrochloride , 4R) -4- (4-hydroxy-phenyl) -piperidin-3-o1; b) the reaction with di-tert-butyl-dicarbonate in the presence of a base to form tert-butyl ester of (3R, 4R) -3-hydroxy-4- (4-hydroxy-phenyl) -piperidm-1- acid carboxylic; c) the reaction with 1- (3-chloro-propoxymethyl) -2-methoxy-benzene and potassium carbonate to produce tert-butyl ester of (3R, 4R) -3-hydroxy-4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -pipepdine-1-carboxylic acid; d) the reaction with 2-chloromethyl-7- (2-trimethylsilanyl-ethoxymethoxy) -naphthalene and sodium hydride forms tert-butyl ester of (3R, 4R) -4- [4- [3- (2-methoxy) benzyloxy) -propoxyl-phenyl] -3- [7- (2-trimethylsilanyl-β-ethoxymethoxy) -naphthalen-2-ylmethoxy] -piperidine-1-carboxylic acid; e) the reaction with hydrochloric acid produces tert-butyl ester of (3R, 4R) -3- [7-hydroxy-naphthalene-2-yloxymethyl] -4- [4- [3- (2-methoxy-benzyloxy) - propoxy] -feml] -piperidine-1-carboxylic acid; f) reaction with 1- (2-hydroxy-ethyl) -4-methyl-piperazine and triphenylphosphine produces (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) tert-butyl ester) -propoxy] -phenyl] -3- [7- [2- (4-methyl-piperazin-1-yl) -ethoxy] -naphthalen-2-ylmethoxy] -piperidine-1-carboxyl ester, followed by: g) a reaction with hydrochloric acid

12. The process according to any of claims 1 to 10, wherein a compound of formula 1 is converted to (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy?) -propoxy] -phenyl ] -3- (1,2,3,4-tetrahydro-quinolin-7-ylmethoxy) -piperidine, characterized in that: a) (3R, 4R) -4- (4-benzyloxy? -phenyl) -1- (R) -1-phenyl-ethyl) -piperidin-3-ol hydrochloride reacts with hydrogen to produce (3R, 4R) -4- (4-hydroxy-phenyl) -piperidin-3-ol; b) the reaction with di-tert-butyl-dicarbonate in the presence of a base to form tert-butyl ester of (3R, 4R) -3-hydroxy-4- (4-hydroxy-phenyl) -piperidine-1-carboxylic acid; c) the reaction with 1- (3-chloro-propoxymethyl) -2-methoxy-benzene and potassium carbonate to produce tert-butyl ester of (3R, 4R) -3-hydroxy-4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl] -piperidine-1-carboxylic acid; d) the reaction with 7-bromomethyl-quinoline hydrobromide and sodium hydride to produce tert-butyl ester of (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxy] -phenyl acid ] -3- (quinolin-7-yl-methoxy) -piperidine-1-carboxylic acid; ~ e) reaction with hydroborate produces tert-butyl ester of - (3R, 4R) -4- [4- [3- (2-methoxy-benzyloxy) -propoxyl-phenyl] -3- (1, 2, 3) , 4-tetrahydro-quinolin-7-ylmethoxy) -piperidine-I-carboxylic acid; followed by f) a reaction with hydrochloric acid.

13. A compound according to formula 1 or a salt thereof, characterized in that R ', R ~, Rj R'J R "and A are as defined in any of claims 1 to 6.

14. A compound according to formula 2 or a salt thereof, characterized in that R1, R ~, R3, R'J Rc and A are as defined in any of claims 1 to 6.

15. A compound according to formula 5 or a salt thereof characterized in that R 'and A are as defined in any of claims 1 to 6 and R6 is alkyl, cycloalkyl, alkenyl, aryl, aralkyl, aralkoxyalkyl, alkylsulfonyl or arylsuifoniia.

16. A compound according to any of claims 13, 14 and 15, characterized in that it is selected from: (3R, 4R) -4- (4-benzyloxy-phenyl) -1- ((R) -1-phenyl-ethyl-1-piperidin-3-o1; (R) -4- (4-benzyloxy-phenyl) -1- (1-phenyl-ethyl) -1,2,3-tetrahydro-pyridine; (R) -A- (4-benzyloxy-phenyl) -1- (1-phenylethyl) -pipepd-4-al.

17. The use of a compound according to claim 13, in the preparation of renin inhibitors

18. A compound as obtained by the process according to any of claims 1 to 10. SUMMARY OF THE INVENTION " The present invention concerns a process for the preparation of a compound of formula 1 or salts thereof 1 characterized in that the process comprises a) Hydroboration of a compound of formula 2 In such formula A is arylene; R1 is -C * RR, R '; R- is an -O-alkyl, -O-cycloalkyl; -O-alkenyl, -O-aryl, -O-aralkyl, -O-aralcaxyalkyl, -O-alkylsulfonyl, -0-arylsulfonyl, chlorine, bromine or iodine; R3 hydrogen; R4 is an aryl; R5 is an alkyl, cycloalkyl, aryl, alkoxyalkyl or hydroxyalkyl; and C * is an asymmetric carbon atom. b) optionally followed by isolation of the desired stereoisomer.