Patent ID: 6774259
Filing Date: 2004-08-10
Classification: A61P,C07B,C07C

Abstract:
A process for the synthesis of a compound of formula (I) wherein R represents a linear or branched (C1-C6)alkyl, wherein alanine of formula (III): is condensed with a compound of formula (IV): wherein R is as defined for formula (I), with hydrogenation which is catalyzed by 5% palladium-on-carbon, in water, at a pressure of 1 to 30 bar, at a temperature of 10 to 60Â° C., in the presence of sodium hydroxide in an amount of up to 0.5 mol/mol of a compound of formula (IV), and the reaction mixture is then acidified to a pH of 3 to 3.5, to yield a precipitate, which is filtered and recrystallized from acetonitrile, to yield the compound of formula (I) in optically pure form.