PROCESS FOR PREPARATION OF SUBSTANTIALLY PURE FOSAMPRENAVIR CALCIUM AND ITS INTERMEDIATES

摘要

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