β-氯代巴豆醛CH_3CCl=CHCHO(α、β-不饱和醛)是合成磺胺甲基嘧啶等有机化合物的中间体。 Julia和Dohnal曾报道过β-氯代巴豆醛的合成方法。Julia的方法是: 这两种方法的得率都较低。氧化这一步,不加丙酮得率仅33.3％,加入丙酮也不过是50％。并且所用的铬酸有进一步氧化的可能,不易控制,同时要污染环境。因而,作者改用硝化、成盐、酸解的新方法制备β-氯代巴豆醛: β-Chlorocrotonate CH_3CCl = CHCHO (α, β-unsaturated aldehyde) is an intermediate for the synthesis of organic compounds such as sulfamerazine. Julia and Dohnal have reported the synthesis of β-chlorocrotonate. Julia’s approach is: Both methods have lower yields. Oxidation step, without acetone yield was only 33.3%, but also add acetone is only 50%. And the use of chromic acid has the possibility of further oxidation, not easy to control, at the same time to pollute the environment. Thus, instead of using nitration, salt formation, acid hydrolysis of a new method for the preparation of β-chloraldehyde: