Unusual reaction of sulphur tetrafluoride: conversion of the methyl group into difluoromethyl and trifluoromethyl groups

Article abstract of DOI:10.1016/0022-1139(95)03331-8

The reaction of 2,5-dimethyl-3,4-furandicarboxylic acid (1) with sulphur tetrafluoride gave crystalline 2,5-dimethyl-4-trifluoromethyl-3-furanoyl fluoride (2) and a liquid composed of 2-methyl-5-difluoromethyl-3,4-bis(trifluoromethyl)furan (4), 2-methyl-3,4,5-tris(trifluoromethyl)furan (5) and only small amounts of the expected 2,5-dimethyl-3,4-bis(trifluoromethyl)furan (3). - Keywords: Sulphur tetrafluoride; Fluoromethylfurans; Furandicarboxylic acid; Methyl group fluorination; NMR spectroscopy; Mass spectrometry