Lipase-catalyzed resolution of both enantiomers of Ornidazole and some analogues

Abstract The resolution of the enantiomers of the chemotherapeutic Ornidazole ( Tiberal ®) 1a was achieved by acetylation of the racemic compound with vinylacetate in the presence of lipase Amano PS (from Pseudomonas cepacia ). The halogen analogues 4a–6a and the corresponding 4-nitro-derivatives 1b and 4b–6b were also synthesized and the enantiomers were separated by kinetic enzymatic resolution. The absolute configuration of two compounds was determined by X-ray crystallography.