2,3-Di:chloro-1,3-butadiene prepn. from 2,3,4-tri:chloro-1-butene - by reacting with a dry sodium alcoholate soln. in the corresponding alcohol

摘要

Prepn. of 2.3-dichloro-1,3-butadione (I) is effected by dehydrochlorination of 2,3,4-trichloro-1-butene (II) by reaction with a soln. in an alcohol of the Na salt of >=5C alcohol of formula R1 CHOH R2 (III) where R1 and R2 are each H, 1-7C alkyl gp., 5-7C cycloalkyl or phenyl with a total of 4-14C in (III). The reaction temp. is from 0-50 degrees C, and (I) is sepd. from the reaction mixt. by distn. Prod. (I) is useful as material for the prepn. of polymers.