Patent ID: 9505787
Filing Date: 2016-11-29
CPC Classification: C07D,C07F

Claim Text:
1. A process for the preparation of Bortezomib, said process comprising: a) coupling (1R)-3-methyl-1-[(3aS,4S,6S,7aR)-3a5,5-trimethylhexahydro-4,6-methano-1,3,2-benzodioxaborol-2-yl]butan-1-amine of formula (II) or its salt with N-(tert-butoxycarbonyl)-L-phenylalanine of formula (III) in a first solvent in the presence of a first coupling agent and a first base to obtain tert-butyl[1-({(1S)-3-methyl-1-[(3aS,4S,6S,7aS)-3a,5,5-trimethylhexahydro-4,6-methano-1,3,2-benzodioxaborol-2-yl]butyl}amino)-1-oxo-3-phenylpropan-2-yl]carbamate of formula (IV) wherein step a) does not comprise solvent exchange; b) deprotecting tert-butyl[1-({(1S)-3-methyl-1-[(3aS,4S,6S,7aS)-3a,5,5-trimethylhexahydro-4,6-methano-1,3,2-benzodioxaborol-2-yl]butyl}amino)-1-oxo-3-phenylpropan-2-yl]carbamate of formula (IV) using an alcoholic solution of an inorganic acid to obtain N-{(1S)-3-methyl-1-[(3aS,4S,6S,7aS)-3a,5,5-trimethylhexahydro-4,6-methano-1,3,2-benzodioxaborol-2-yl]butyl}phenylalanine of formula (V) or its salt; c) coupling the compound of formula (V) or its salt with pyrazine-2-carboxylic acid of formula (VI) in a second solvent in the presence of a second coupling agent and a second base to obtain N-{(1R)-3-methyl-1-[(3aS,4S,6S,7aS)-3a,5,5-trimethylhexahydro-4,6-methano-1,3,2-benzodioxaborol-2-yl]butyl}-Nα-(pyrazin-2-ylcarbonyl)-L-phenylalaninamide of formula (VII); and d) deprotecting the compound of formula (VII) to obtain Bortezomib or its anhydride.