Synthesis and chemistry of CF3C6F4OC6F4NH2 (RFNH2) and pseudohalogen derivatives; crystal structures of RFX (X = COOH, COCl, CN, N-3, NCS, NHCOCONHRF)

The synthesis of the new perfluorinated 4-(4'-trifluoromethyl-tetrafluoroph enoxy)-tetrafluoroaniline (RFNH2, 4) was accomplished via a 4-step route in volving standard procedures: carboxylation of RFLi, chlorination of RFCOOH (1), amidation of RFCOCl (2) and Hofmann degradation of RFCONH2 (3). Diazot ation and reaction with azide as well as treatment of 4 with acid chlorides produced the pseudohalides RFN3 (5), RFNCS (6) and RFNCO (7). The reaction with oxalyl chloride led to the formation of two products RFNHCOCOCl (8) a nd RFNHCOCONHRF (9). The thionyl imide RFNSO (10) is formed upon reaction w ith thionyl chloride. All products were identified and characterized by spe ctroscopic methods. The molecular structures of 1, 2, 5, 6, 9 and RFCN (3 a ) have been determined by X-ray crystallography, among them the azide 5 and the isothiocyanate 6 as the first crystal structures of perfluorinated azi des/isothiocyanates bound to carbon.