Synthesis 2006(11): 1757-1759  
DOI: 10.1055/s-2006-942356
SHORTPAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Benzoic Acids by Aerobic Photooxidation with Hydrobromic Acid

Shin-ichi Hirashima, Akichika Itoh*
Gifu Pharmaceutical University, Mitahora-higashi, Gifu 502-8585, Japan
e-Mail: itoha@gifu-pu.ac.jp;
Further Information

Publication History

Received 8 December 2005
Publication Date:
05 May 2006 (online)

Abstract

A methyl group at an aromatic nucleus is oxidized directly to the corresponding carboxylic acid in the presence of molecular oxygen and catalytic hydrobromic acid under photoirradiation.

    References

  • 1 Comprehensive Organic Transformations: A Guide to Functional Group Preparations   Larock RC. Wiley-VCH; New York: 1999. 
  • 2 Itoh A. Hashimoto S. Kodama T. Masaki Y. Synlett  2005,  2107 
  • 3 Photooxidation of alkylbenzene in the presence of hydrobromic acid under oxygen has been previously reported; however, the corresponding carboxylic acids were obtained in very low yields, see: Nakada M. Fukushi S. Hirota M. Bull. Chem. Soc. Jpn.  1990,  63:  944 
4

A trace amount of 4-tert-butylbenzyl bromide was detected in the reaction mixture when 1 was used as a substrate.