Patent ID: 7368580

Claim:
A process for the synthesis of a compound of formula (I): and its pharmaceutically acceptable salts, wherein a compound of formula (II): wherein R represents hydrogen, benzyl or linear or branched (C i -C 6 )alkyl, is reacted with a compound of formula (III) having the (R) configuration: wherein G represents chlorine, bromine, iodine, hydroxy, p-toluenesulphonyloxy, methanesulphonyloxy or trifluoromethanesulphonyloxy, in the presence of a base, to yield a compound of formula (IV): which is reacted with the compound of formula (V) having the (S) configuration: 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).