| abstract |
A process for preparing halogenated β -lactam compounds,ncharacterized in that a β-lactam amino compound of thenformula (1) is reacted with nitrous acid or nitrite in anslurry dispersion state in water, under acid condition in thenpresence of halogen molecules, thereby obtaining a halogenatednβ-lactam compound of the formula (4)n nwherein n is an integer of 0 to 2; A is the formula (2) orn(3); R 1 and R 2 are the same or different and are hydrogennatom, halogen atom, C 1 ∼C 3 alkyl group, C 2 ∼C 4 alkenyl group, C 2 n∼C 4 alkynyl group, nucleophilic group, or CH 2 R 3 ; and R 3 isnhalogen atom or nucleophilic groupn nwherein A is as defined above; X 1 is hydrogen atom or halogennatom; and X 2 is halogen atom. |