A general method of halogenation for synthesis of α-halodifluoromethyl ketones and [18F]-labeled trifluoromethyl ketones

A convenient general method of halogenations suitable for synthesis of α-halodifluoromethyl ketones is reported. Reaction of 2,2-difluoro-1-aryl-1-trimethylsiloxyethenes (difluoro silyl enol ethers) (2a–e) with halogens at low temperature (−30 to −78 °C) produced a high yield of α-halodifluoromethyl ketones (1a–j). This one-step simple method can be highly useful for synthesis of [18F]-labeled α-trifluoromethyl ketones.