Unsaturated nitrogen compounds containing fluorine. Part 16. The synthesis of 3,5-bis(trifluoromethyl)-1H-1,2,4- triazole and some 4-substituted derivatives from 2,5-dichloro-1,1,1,6,6,6-hexafluoro-3,4-diazahexa-2,4-diene

Article abstract of DOI:10.1016/0022-1139(94)03199-A

The dichloroazine 5 has been converted into the monoaminoazines CF3C(NHR)=NN=CClCF3 (6) and the diaminoazines CF3C(NHR)=NN=C(NHR)CF3 (4) by reaction with ammonia or the appropriate primary amino compound; with hydroxylamine the syn-oxime CF3CCl=NNHC(CF3)=NOH (8) (86percent) was formed.The mixed diaminoazines CF3C(NHR)=NN=C(NHR')CF3 (4) have been synthesised from the monoaminoazines 6a-d.A solution of the diaminoazine 4c, heated in ethanol under reflux, gave 3,5-bis(trifluoromethyl)-1H-1,2,4-triazole (1a) (28percent) and its ammonium salt NH4^+- (7b) (54percent), while the azines 4g and 4j under the same conditions each afforded 4-phenyl-3,5-bis(trifluoromethyl)-4H-1,2,4-triazole (2c) (ca. 85percent).Thermolysis of the diaminoazines 4c-f and 4h in vacuo over the range 120-150 deg C gave the following results: 4c--->7b (98percent); 4d--->MeNH3^+- (7c) (ca. 26percent) + Me4N^+- (7d) (ca.13percent) + 4-methyl-3,5-bis(trifluoromethyl)-4H-1,2,4-triazole (2b) (54percent) + 1-methyl-3,5-bis(trifluoromethyl)-1H-1,2,4-triazole (1b) (1.5percent); 4e---> the 4-carbomethoxymethyltriazole (2e) (93percent); 4f---> the 4-carboethoxymethyltriazole (2f) (82percent); 4h--->1a (11percent) + 2b (54percent) + 7c (31percent).Treatment of salt 7b with aqueous hydrochloric acid afforded the triazole 1a (75percent). - Keywords: Unsaturated nitrogen compounds; Synthesis; Bis(trifluoromethyl)triazole; NMR spectroscopy; Mass spectrometry