Patent ID: 7183308

Claim:
A process for the synthesis of compounds of formula (I): and pharmaceutically acceptable salts thereof, wherein a compound of formula (II): wherein R 1 represents a hydrogen atom, a benzyl group or a linear or branched (C 1 –C 6 )alkyl group, is reacted with a compound of formula (III) having the S configuration: wherein X represents a halogen atom and R 2 represents a protecting group for the amino function, in the presence of a base, to yield, after deprotection of the amino function, a compound of formula (IV): which is reacted with a compound of formula (V): wherein G represents a chlorine, bromine or iodine atom or a p-toluenesulphonyloxy, methanesulphonyloxy or trifluoromethanesulphonyloxy group, in the presence of a base, to yield a compound of formula (VI): which is hydrogenated in the presence of a catalyst to yield, after deprotection where necessary, the compound of formula (I).