| 摘要 |
Pivaloyl chloride and an aroyl chloride (2), are prepared by reaction of pivalic acid on a trichloromethyl aromatic compound (1). The reaction is effected according to the following reaction scheme: R = halogen, 1-4C alkyl, perfluoro 1-4C alkyl, or -COCl; m = 0, 1, or 2; n = 1, 2, or 3 such that the indicated trichloromethyl groups are not situated on adjacent C atoms when n is greater than 1. The reaction is effected as follows: pivalic acid, (1), and with a Friedel-Crafts catalyst are introduced continuously and simultaneously into a reaction zone, and stirred at 60 - 180 degrees C under reduced pressure. The products and starting materials emitted in the gaseous flow at the top of the reactor are continuously separated and condensed, to give a liquid mixture of pivaloyl chloride and benzoyl chloride. Counter-current washing gives (1), the uncondensed gaseous mixture containing HCl. The reaction mixture from the base of the reaction zone, containing most of the (2) produced and the catalyst is extracted and treated to a reactive distillation to separate (2). The reactive distillation may take place in the presence of a further quantity of Friedel -Crafts catalyst. |
