The preparation of a 2-halocyclobutanone by contacting a 2,2-dihaloalkanoyl halide with an ethylenically unsaturated compound at a temperature of at least 5.degree. C in the presence of dispersed zinc or tin and certain alkanones is conducted by using a molar ratio of zinc (or tin) to 2,2-dihaloalkanoyl halide below 1.00, with the zinc (or tin) in the form of particles having a largest dimension of up to 0.05 mm, and adopting a temperature of up to 55.degree. C.
在存在分散的
锌或
锡和某些酮的情况下,通过将2,2-二卤代酰基卤与
乙烯不饱和化合物在至少5℃的温度下接触,制备2-卤代
环丁酮,使用
锌(或
锡)与2,2-二卤代酰基卤的摩尔比低于1.00,
锌(或
锡)以最大尺寸为0.05毫米的颗粒形式存在,并采用高达55℃的温度。