A. Pinkus, F. Ma, L. Meng
Apr 1, 2004
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0
Influential Citations
5
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Journal
Organic Preparations and Procedures International
Abstract
2-Chloroand 2,5-dichlorobenzophenones (3b and 3a) were required in connection with another project. The yields of the reported syntheses of 2,5-dichlorobenzophenone (3a) from the Friedel-Crafts reaction of p-dichlorobenzene with benzoyl chloride are either not reported' or low (20%2 and 8%3) and these preparations involve long reaction times and vigorous conditions. In our own preliminary work, only a 17% yield of 3a was obtained via the FriedelCrafts reaction after 49 hrs. The low yields probably result from the ring-deactivating effect of the two chlorine substituents. The synthesis reported here produces 3a from la in two steps, each proceeding in high yields. The compound formed in the first step (2a) need not be isolated and may be heated directly after formation; it should be noted that both steps are new reactions (Scheme 1).