Patent ID: 6743949
Filing Date: 2004-06-01
Classification: A61P,C07B,C07C

Abstract:
A process for producing ketamine enantiomers comprising the steps of:a) preparing a solution of racemic ketamine in an organic solvent in a concentration ranging from 0.1M to 1.0M of ketamine; b) adding a resolution agent in an amount ranging from 0.25 to 0.80 molar equivalent in relation to ketamine base; c) adding water in an amount ranging from 5% to 20% in relation to the organic solvent; d) dissolving all solids by heating; e) separating one diastereomeric salt of one ketamine enantiomer by solid-liquid separation procedures selected from filtration, centrifugation, and decantation; f) dissolving the diastereomeric salt of ketamine in water in order to obtain a concentration not higher than 20% of the ketamine diastereomeric salt; g) adding an alkaline solution to reach a pH ranging from 9 to 12 to precipitate the ketamine enantiomer; h) purifying the ketamine enantiomer by crystallization using a solvent selected from the group consisting of C1-C6 alcohols, C5-C12 alkanes, C5-C12 cycloalkanes, acetone, or mixtures thereof; i) evaporating the remaining solvent from step (e) separating the other enantiomer; j) dissolving the resulting solid from step (i) in enough amount of a 0.1N to 3.0N hydrochloric acid solution, and proceeding as in steps (g) to (h) in order to separate the other ketamine enantiomer.