A practical and robust process to produce SB-214857, Lotrafiban, ((2S)-7-(4,4′-bipiperidinylcarbonyl)-2,3,4,5-tetrahydro-4-methyl-3-oxo-1H-1,4-benzodiazepine-2-acetic acid) utilising an enzymic resolution as the final step

During the scale-up of a chemical process to produce phase II supplies of the chiral compound Lotrafiban, partial racemisation occurred to produce drug substance of unacceptable chiral purity. A new route capable of producing several hundred kilograms of Lotrafiban of high chiral purity had to be rapidly identified and scaled up. The strategy adopted was to employ an enzymic resolution as the final step, thus introducing the chirality under very mild conditions to prevent any racemisation. This was achieved using an immobilised form of the Candida antarctica B lipase in water at 30 degreesC. The biotransformation was demonstrated to be a robust, reliable, and an economic way to introduce the chirality into the Lotrafiban molecule.