| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject new compound useful as an intermediate for various kinds of cephalosphorin-based antibiotics. SOLUTION: This new compound, a 3-iminochloroazetidinone derivative, is expressed by formula I (R<1> is an aryl; R<2> is a ctarboxyl-protecting group; R<3> is an aryl), e.g. p-methoxybenzyl-2-[3-(1-chloro-2,2-dichloro-2- phenylethylideneamino)-4-benzenesulfonylthio-2-azetidinon-1-yl]-3-chlo romethyl-3- butenoate. The compound of formula I is obtained, for example, by reaction of an azetidinone derivative of formula II with phosphorus pentachloride in an organic solvent in the presence of a hydrochloric acid scavenger to form an iminochloromodification of formula III, which is then reacted with a chlorinating agent in an organic solvent at <=0 deg.C. |
