A new synthesis of lotrafiban SB-214857-A is reported. The key steps are the preparation of racemic (4-melhyl-3-oxo-2,3,4,5-tetrahydro-1H-benzo[c][1,4]diazepin-2-yl)-acid methyl ester from 2-nitrobenzyl alcohol, a resolution using an immobilised lipase enzyme and a palladium-catalysed aminocarbonylation reaction. (C) 2001 Elsevier Science Ltd. All rights reserved.