Abstract:
The present invention describes a process for the synthesis of ursodeoxycholic acid wherein the purification of the crude ursodeoxycholic acid (containing approximately 13-15% of chenodeoxycholic acid impurity) takes place first passing through a salification with imidazole and a subsequent purification via "methyl ester", which allows a finished product with an extremely low content of known "cheno and "litho" impurities to be obtained. The present invention also describes the recovery steps of cholic acid and 3α-hydroxy-7-ketocholanic acid from the mother liquors of process intermediates.
Abstract:
Process for crystallising Bupropion hydrochloride comprising the following stages: a) Bupropion hydrochloride is dissolved in a mixture comprising methanol and a precipitating solvent for Bupropion hydrochloride; b) any insoluble residue is removed; c) the solution is distilled at atmospheric pressure until the precipitation reaction is triggered; d) the following are added: I) a precipitating solvent for Bupropion hydrochloride and II) hydrochloric acid until a pH ≤ 2 is obtained; e) the mass is cooled to a temperature less than 10° C, preferably between 0 and 3° C and the precipitate obtained is separated.
Abstract:
Process for preparing 3α-7α(β)-dihydroxy-6α(β)-alkyl-5β-cholanic acid (I) in which R is a linear or branched C 1 -C 5 alkyl and the relative intermediates 3α-hydroxy-6β- alkyl-7-keto-5β-cholanic (VIII) and 3α-hydroxy-6α-alkyl-7-keto-5β-cholanic (IX).
Abstract:
A process for synthesis of 1-(aminomethyl)cyclohexane acetic acid hydrochloride (Gabapentin hydrochloride) comprising: a) Reaction of a mixture of acetic anhydride/ammonium acetate with 1,1-cyclohexanediacetic acid to yield 3,3-pentamethylene glutarimide; b) Treatment of 3,3-pentamethylene glutarimide with sodium hydroxide in an aqueous solution up to dissolution, dripping the solution thus obtained into a to sodium hydroxide/sodium hypochlorite mixture, which is also aqueous, followed by acidification with hydrochloric acid to yield gabapentine hydrochloride.
Abstract:
A process is described for the production of Rivaroxaban, a compound having the following structural formula: (I) by means of obtaining a novel intermediate of said process.
Abstract:
A new process is described for the preparation of deferasirox, 4-[(3 Z ,5 E )-3,5-bis(6- oxo-1 -cyclohexa-2,4-dienylidene)-1,2,4-triazolidin-1 -yl]benzoic acid, having the following structural formula (I).
Abstract:
There is described a process for the preparation of cinacalcet hydrochloride (I) which includes the steps of: a) reacting (R)-(+)-1-(1-naphthyl)ethylamine (II) with 3-[3-(trifluoromethyl)phenyl]propenaldehyde (III) to afford the non isolated intermediate (R)-N-[3-[3-(trifluoromethyl)phenyl]-2-propenylimino-N-[1-(1 - naphthyi)ethy!amine (IV); b) reducing the non isolated intermediate (R)-N-[3-[3-(trifluoromethyl)phenyl]-2-propenylimine-N-[-1 -(1 -naphthyl)ethylamine (IV) with a sequential addition of: - a solution of sodium borohydride, methanol and a base, - oxalic acid and - a base to obtain (R)-N-[3-[3-(trifluoromethyl)phenyl]-2- propenyl]-1-(1-naphthyl)ethylamine (V) by passing through the precipitation of the oxalate salt of compound (V) after the addition of oxalic acid; c) hydrogenating (R)-N-[3-[3-(trifluoromethyl)phenyl]-2-propenyl]-1 -(1 - naphthyl)ethylamine (V) thus obtaining (R)-N-(3-(3- (trifluoromethyl)phenyl]propyij-i-(i -naphthyl)ethylamine cinacalcet base (Vl), which is retaken in ethyl acetate; and d) treating the- solution of cinacalcet base (Vi) in ethyl acetate with hydrochloric acid to afford cinacalcet hydrochloride (I).
Abstract:
A process for the preparation of 4-[2-(5-ethyl-2-pyridyi)ethoxy]nitrobenzene is described, which comprises the step of reacting 2-(5-ethyl-2-pyridyl)ethanol with 1-fluoro-4-nitrobenzene in acetone in the presence of an alkali metal hydroxide. The intermediate 4-[2-(5-ethyl-2-pyridyI)ethoxy]nitrobenzene is used for the preparation of pioglitazone.
Abstract:
Process for preparing 2-methoxycarbonylmethyl-6,6-dimethyl-2-tetrahydropyran carboxylic acid (I) comprising: a) Reaction of 5-bromo-2-methyl-2-pentene (III) with magnesium and then diethyloxalate to obtain ethyl-2-oxo-6-methyl-5-heptenoate (IV); b) Reaction of ethyl-2-oxo-6-methyl-5-heptenoate (IV) with an alkali amide and methyl acetate to obtain ethyl-2- methoxycarbonylmethyl^-hydroxy-θ-methyl- 5-heptenoate (V); c) Reaction of ethyl-2- methoxycarbonylmethyl-2-hydroxy-6-methyl-5-heptenoate (V) with an alkali metal hydroxide to obtain the corresponding 2-carboxymethyl- 2-hydroxy-6-methyl-5-heptenoic acid (Vl); d) Cyclisation of 2-carboxymethyl-2-hydroxy-6-methyl-5-heptenoic acid (Vl) with formic acid to give 2-carboxymethyl-6,6-dimethyl-2-tetrahydropyrancarboxylic acid (VII); e) Monoesterification of 2-carboxymethyl-6,6-dimethyl-2- tetrahydropyrancarboxylic acid (VII) to 2-methoxycarbonylmethyl-6,6-dimethyl- 2-tetrahydropyran carboxylic acid (I), characterised in that in stage (e) the 2-methoxycarbonylmethyI-6,6-dimethyl-2- tetrahydropyran carboxylic acid (I) is purified by means of the formation of the corresponding salt with cyclohexylamine (IA).
Abstract:
Process for preparing raloxifene hydrochloride with a purity greater than 98% and low aluminium content comprising the following stages a) demethylation of 6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene in pyridine and hydrochloric acid to obtain 6-hydroxy2-(4-hydroxyphenyl)benzo[b]thiophene in pyridine hydrochloride, b) acetylation of 6-hydroxy-2-(4hydroxyphonyl)benzo[b]thiophene with an acetylating agent to obtain the corresponding 6-acetoxy-2-(4 acetoxyphenyl)benzo[b]thiophene, c) acylation of 6-acetoxy-2-(4-acetoxyphonyl)benzo[b]thlophene with 4-(2 piperidinoethoxy)benzoylchloride hydrochloride with aluminium trichloride in halogenated solvent to obtain 6-acetoxy-2-(4acetoxyphenyl)-3-[4-(2 piperidinoethoxy)benzoyl]-benzo[b]thiophene, d) hydrolysis of 6-acetoxy-2-(4-acetoxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyll benzo[b]thiophene according to the following operating conditions: dl) treatment of 6-acetoxy-2-(4-acetoxyphonyl)-3-[4-(2piperidinoethoxy)benzoyl]benzo[b]thiophene with alkaline hydroxide in alcohol solvent, d2) acidification of the product obtained in the preceding stage (dl) with a strong acid, to obtain the corresponding raloxifene salt with the strong acid, characterised in that the strong acid used in stage (d2) is concentrated hydrochloric acid.