Electrolytic partial fluorination of organic compounds. 36. Regioselectiveanodic fluorination of phenylthiolated benzofuranone and benzothiazole derivatives

The anodic fluorination of 3-phenylthio-2-benzofuranones and alpha-phenylth io-2-benzothiazolylacetonitrile was investigated. Both derivatives were sel ectively fluorinated in good yields at the carbon alpha to the sulfur atoms in Et4NF . 3HF/DME using a platinum anode and an undivided cell. The fluor ination yields of the benzofuranone derivatives were improved by the additi on of Ph2S, which was not effective in the case of the benzothiazole deriva tive. The fluorination yield of the benzothiazole derivative was strongly a ffected by the stirring state of the electrolytic solution or the applied a node potential. (C) 1999 Elsevier Science S.A. All rights reserved.