Patent ID: 7915421

Claim:
Method for preparing (S)(+)phenyl-acetic acid derivatives having the general formula (I): wherein R 1 is a methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, 2-methyl-propyl or benzyl group, and R 2 is a methyl, ethyl or propyl group, characterized in that a compound having the general formula (II): wherein R 1 is as given above, and R 3 is a benzyl or substituted benzyl or allyl group which is substituted at the phenyl ring by at least one electronegative, electron supplying substituent, or a substituted benzyl group, which is substituted at methylene by one electronegative, or an electron-supplying substituent, or a suitable salt of a compound having the general formula (II), is reacted with a compound having the general formula (Ill): wherein R 2 is as given above, and R 4 is hydrogen or a protective group that can be removed hydrolytically, and the hydrolytically removable protective group R 4 that may be present is removed thereafter.