Thermal conversion of fluorinated azo-compounds into indazoles: the case of 2,5,6-trifluoro-4-(2,4,6-trimethylphenylazo)pyrimidine

Abstract Thermal dehydrofluorination of 2,5,6-trifluoro-4-(2,4,6-trimethylphenylazo) pyrimidine in boiling xylene to 2,4-difluoro-7,9-dimethyl-5 H -pyrimido [4,5- c ]benzo[1,2]diazepine is accompanied by the formation, inter alia , of 5,7-dimethyl-2-(2,5,6-trifluoropyrimidin-4-yl)- 2H -indazole. The same product is formed when tetrafluoropyrimidine is treated with 5,7-dimethylindazole.