AN IMPROVED ONE POT PROCESS FOR MAKING KEY INTERMEDIATE FOR GEMCITABINE HCL

摘要

An improved one pot process for preparing 2-deoxy-D-erythro-2,2-difluoro-pentafuranose-1-ulose-3,5-dibenzoate of Formula (I) comprising hydrolysis of (erythro:threo) alkyl-3-dioxalan-4-yl-2,2-difluoro-3-hydroxy propionate of Formula (III) where alkyl group is having C1-C4 number of carbon atoms using a mild acid and selectively isolating 2-deoxy-D-erythro-2,2-difluoro-pentafuranose-1-ulose-3,5-dibenzoate from the mixture of erythro & threo enantiomers using ethyl acetate, ethylene dichloride and diisopropyl ether as solvents with improved yield and purity.