84603-41-8Relevant academic research and scientific papers
Perfluoroalkanesulfonic acid catalyzed acylations of alkylbenzenes: Synthesis of alkylanthraquinones
Effenberger,Buckel,Maier,Schmider
, p. 1427 - 1430 (2007/10/03)
The acylation of alkylbenzenes 1 with benzoyl chloride 2 and catalytic amounts of perfluorobutanesulfonic acid affords the corresponding 2-, 3-, and 4-alkylbenzophenones 3 with unusually high amounts of ortho products. Surprisingly, even tert-butylbenzene reacts under these reaction conditions without any acid catalyzed dealkylation. The yield of benzoylation of p-xylene 4 with benzoic acid in the presence of 5 mol% C4F9SO3H to give 2,5-dimethylbenzophenone 5 could significantly be improved from 14% to 90% by continuous removal of water formed during the acylation. Also in the preparation of alkylanthraquinones 7 by reaction of alkylbenzenes with phthalic anhydride, water removal is the decisive factor to obtain satisfactory yields for the second acylation, allowing to cyclize 6 with catalytic amounts (10 mol%) of CF3SO3H in organic solvents to the corresponding alkylanthraquinones 7.
