Syntheses of 2-(bromodifluoromethyl)benzoxazole and 5-(bromodifluoromethyl)-1,2,4-oxadiazoles

Facile syntheses of CF2Br-substituted heterocycles are reported. Preparation of 2-(bromodifluoromethyl)benzoxazole (2) was achieved in two steps by reaction of 2-aminophenol (3) with CF2BrCO2Et to give amide (4), followed by cyclization of 4 with PPA to give 2. The 5-(bromodifluoromethyl)-1,2,4-oxadiazoles (6a-c) were prepared by one step reaction of amidoximes (5a-c) with CF2BrCO2Et. These CF,Br-substituted heterocycles are intermediates in an ongoing investigation of the synthesis of inhibitors of HIV reverse transcriptase having a CF2 substitution. (C) 1999 Elsevier Science S.A. All rights reserved.