PERSULPHATE OXIDATION OF CARBOXYLIC ACIDS.
Abstract
Previous work on the persulphate oxidation of o-benzoylbenzoic acids, biphenyl-2-carboxylic acids and o-phenoxybenzoic acids has been extended to the oxidation of biphenyl-2-carboxylic acid amides, o-(arylthio)- and o-(arylsulphonyl)benzoic acids. Oxidation of a series of N-substituted and bz-substituted biphenyl-2-carboxylic acid amides resulted in the formation of substituted phenanthridones and the method is of general value for the synthesis of this class of compounds. In some cases the phenanthridone is accompanied by some benzocoumarin. Oxidation of 2'-substituted amides may result in elimination of the substituent and these compounds are not suitable for the synthesis of substituted phenanthridones. Oxidation of o-(p-tolylthio)benzoic acid resulted in a migration of the p-tolyl group to the carboxyl radical formed initially, and subsequent dimerisation to give the di-p-tolyl ester of diphenyldisulphide-o,o'dicarboxylic acid. In all cases, the predominant reaction was oxidation on sulphur to the corresponding sulphoxide acids. Persulphate oxidation of o-(phenylsulphonyl)benzoic acid afforded dibenzothiophene dioxide (7%), the o-(p-nitrophenyl) analogue gave 2-nitrodibenzothiophene dioxide (1%). There was a marked reluctance of these acids to undergo oxidative cyclisation. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 31, 1969
- Accession Number
- AD0701947
Entities
People
- R. H. Thomson
Organizations
- University of Aberdeen