Chemo-enzymatic synthesis of optically pure rivastigmine intermediate using alcohol dehydrogenase from bakerʹs yeast

An efficient and practical synthesis of (S)-rivastigmine intermediate was developed by employing a chemoenzymatic step toward the synthesis of chiral intermediate N-ethyl-N-methyl-carbamic acid-3-(1S-hydroxy-ethyl)-phenyl ester (2) using crude alcohol dehydrogenase from bakerʹs yeast with reduced nucleotide adenosine dinucleotide (NADH) as proton donor has been demonstrated.