Synthesis 2000; 2000(10): 1427-1430
DOI: 10.1055/s-2000-7102
paper
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Perfluoroalkanesulfonic Acid Catalyzed Acylations of Alkylbenzenes: Synthesis of Alkylanthraquinones

Franz Effenberger* , Frank Buckel, Andreas H. Maier, Judith Schmider
  • *Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany; Fax + 49(711)6 85 42 69; E-mail: franz.effenberger@po.uni-stuttgart.de
Further Information

Publication History

Publication Date:
31 December 2000 (online)

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.

    >