Patent ID: 6576790
Filing Date: 2003-06-10
Classification: C07C

Abstract:
A process for the preparation of gabapentin starting from gabapentin hydrochloride, which comprises the following steps:preparing a gabapentin hydrochloride aqueous solution; adjusting the pH of said solution to or about to gabapentin isoelectric point by addition of a basic compound comprising a monovalent anion; diafiltering said solution through a membrane highly selective for organic compounds with molecular weight higher than 150 and poorly selective for inorganic monovalent ions, to separate said solution into an aqueous permeate containing chloride ions and a retentate containing unsalified gabapentin substantially free from chloride ions; concentrating said retentate by increasing the pressure exerted on said membrane to obtain a concentration of unsalified gabapentin in the retentate not lower than 5% evaporating the retentate under reduced pressure and at TÂ° C.<35Â° C.; precipitating gabapentin by addition of an alcohol.