| 摘要 |
PURPOSE:To obtain the title compound useful as an intermediate for beta-lactamase inhibitors and a cephalosporin based antibiotic in high purity and high yield, by reacting an azetidinone disulfide derivative with a hydrohalogenic acid in the presence of a nitrite, etc. CONSTITUTION:An azetidinone disulfide derivative expressed by formula I (R represents carboxyl-protecting group; R<1> and R<2> represent H, phthalimide, halogen or acylamino; R<3> represents nitrogen-containing heterocyclic group) [example; 2-oxo-4-(benzothiazol-2-yl)dithio-alpha-isopropenyl-1-azetidine acetic acid p-nitrobenzyl ester] is reacted with a hydrohalogenic acid (example; hydrochloric acid) in the presence of a nitrite (example; sodium nitrite) and/or an ester of nitrous acid to afford the aimed compound expressed by formula II (X represents halogen). |
