| 摘要 |
PURPOSE:To obtain a new beta-lactam compound having an alkylthio or arylthio group at 4 position and useful as an inexpensive synthetic intermediate capable of industrially providing in large amounts and used for beta-lactam-based antibiotics having strong antimicrobial action. CONSTITUTION:A carboxylic acid of formula I [R1 is H, lower alkyl, (protected) hydroxyl-lower alkyl or (substituted) amino; R2 is (substituted) lower alkyl, aryl, etc.] are treated with a halogenating agent to afford a beta-halogenated carboxylic acid and then, this compound a carboxylic acid group of which has been activated with thionyl chloride, etc., is successively made to react with the formula R3-NH2 (R3 is H, aryl, substituted aryl, aralkyl, acyl, lower alkoxycarbonyl, etc.) to give an azide compound of formula III. Then, the azide compound is subjected to cyclization reaction in the presence of a deacidifying agent such as triethylamine to provide the objective beta-lactam compound expressed by the formula IV and used as an intermediate, etc., for beta-lactam- based antibiotics. |
