Several methods have been developed to prepare 1-(benzothiazol-2-ylsulfanyl)-3-chloropropan-2-ol 2 with good to high enantiomeric excess: 70 and 93% ees have in fact been obtained by baker's yeast-induced asymmetric reduction of the ketone precursor 1 and by kinetic resolution performed in the presence of lipase from Pseudomonas sp. (E = 38), respectively. Compounds (R)-(+)-2 and (S)-(-)-2 have also been prepared by a chemical method in 90% yield and with enantiomeric excesses of 98 and 96.4%, respectively. HPLC on Chiralcel OD column separation of enantiomers (separability factor alpha = 1.64) has also been successfully performed. Compound 2 could, in turn, be used for the synthesis in an optically active form of various molecules, including beta-aminoalcohols 6, drugs with potential beta-blocker activity.
Chemical and Chemoenzymatic Routes to 1-(benzothiazol-2-ylsulfanyl)-3-chloropropan-2-ol, a precursor of drugs with potential ƒÒ-blocker activity
FRANCHINI, Carlo;SCILIMATI, Antonio;TORTORELLA, Paolo
2000-01-01
Abstract
Several methods have been developed to prepare 1-(benzothiazol-2-ylsulfanyl)-3-chloropropan-2-ol 2 with good to high enantiomeric excess: 70 and 93% ees have in fact been obtained by baker's yeast-induced asymmetric reduction of the ketone precursor 1 and by kinetic resolution performed in the presence of lipase from Pseudomonas sp. (E = 38), respectively. Compounds (R)-(+)-2 and (S)-(-)-2 have also been prepared by a chemical method in 90% yield and with enantiomeric excesses of 98 and 96.4%, respectively. HPLC on Chiralcel OD column separation of enantiomers (separability factor alpha = 1.64) has also been successfully performed. Compound 2 could, in turn, be used for the synthesis in an optically active form of various molecules, including beta-aminoalcohols 6, drugs with potential beta-blocker activity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
