PROCESS FOR PREPARATION OF SUBSTANTIALLY PURE FOSAMPRENAVIR CALCIUM AND ITS INTERMEDIATES

摘要

The present invention relates to fosamprenavir calcium (la) substantially free of isomer impurity, (3R) tetrahydro-3-furanyl(1S,2R)-3-[[(4-aminophenyl) sulfonyl] (isobutyl) amino]- 1-benzyl-2-(phosphonooxy)propyl carbamate (lb), and its process for preparation thereof. The present invention also provides fosamprenavir calcium intermediate, (S)-3- tetrahydrofuranyl-N-succinimidyl carbonate (Ila) substantially free of (R)-3- tetrahydrofuranylsuccinimidyl carbonate (lib) and its process for preparation thereof.