Patent ID: 6610845
Filing Date: 2003-08-26
Classification: C07D

Abstract:
A process for preparing a compound of formula (II) wherein, R1 represents H, trityl, CH3, CRaRbCOOR2 (Ra and Rb independently of one another represents hydrogen or methyl and R2 represents H or C1-4 alkyl);R3 is CH3, â€”CH&boxH;CH2, CH2OCH3, CH2OCOCH3, R4 is H or a salt or a carboxylic protecting group or a inner salt when R3 is comprising acylating a compound of formula (III) wherein, R5 is H or trimethylsilyl; R3 and R4 are defined as above with a compound of formula I wherein, R1 is as defined above, in the presence of an organic solvent and a base at a temperature in the range of âˆ’10Â° C. to +30Â° C.