Unsaturated nitrogen compounds containing fluorine. Part 10. Reaction of 2,5-dichloro-1,1,1,6,6,6-hexafluoro-3,4-diazahexa-2,4-diene with halide ion and oxygen- and sulphur-centred nucleophiles and of its 2,5-di-iodo analogue with reducing agents and certain nucleophiles

Article abstract of DOI:10.1016/S0022-1139(00)80480-7

The azines CF3CR=NN=CRCF3 (R = F, I, PhO, 2,4-Cl2C6H3O, PhS and EtO) are formed by treatment of the title dichloroazine 1 with an excess of the appropriate nucleophile, while reaction with phosphorus (V) sulphide at 180 deg C gives 2,5-bis(trifluoromethyl-1,3,4-thiadiazole in quantitative yield.In the reaction with NaOEt, the compound CF3C(OEt)=NN=C(ONa)CF3 is also produced from the NaOH impurity present.Di-iodoazine 3b undergoes ready reaction with aniline (1:2 molar ratio) and potassium diethyl phenylmalonate (1:1 molar ratio) to afford the monosubstituted compounds PhN=C(CF3)NHN=CICF3 and (EtO2C)2PhC(CF3)=NN=CICF3, respectively.Azine 1 is not reduced by the reagents NaH, LiAlH4 and NaBH4, but di-iodoazine 3b is reduced by tri-n-butyltin hydride at c. 90 deg C to give mainly the compounds CF3CH=NN=CHCF3, CF3CH=NN=CICF3, CFCH2NHN=CICF3 and possibly CF3CH=NNHCH2CF3; with hydrogen iodide at 200 deg C, the major products are the hydroazines CF3CH=NN=CHCF3 and CF3CH=NN=CICF3 and 2,4,6-tris(trifluoromethyl)-1,3,5-triazene.