PROCESS FOR PREPARATION OF CIDOFOVIR

摘要

The present invention is related to the process for preparation of cidofovir dihydrate comprising reaction of (S)-N1-[(2-hydroxy-3- triphenylmethoxy)propyl]cytosine (Compound II) with diethyl-p-tosyloxymethyl phosphonate using sodium hexamethyldisilazane to give key intermediate phosphonic acid [[(S)-2-(4-amino-2-oxo-l (2h)-pyrimidinyl)-l-(hydroxymethyl)-2- (triphenylmethoxy)ethyl]methyl]diethyl ester (Compound III) which on further reaction with trimethylsilyl bromide followed by treatment with hydrochloric acid yielded cidofovir having desired purity.