Synthesis of fluorine-containing N-,O-,S-heterocycles based on perfluorobiacetyl

The review presents approaches to the synthesis of trifluoromethyl-containing N,O,S-heterocyclic compounds such as imidazolidin-2-ones(thiones), 1,2,4-triazine-3-thiones(ones), 1,2,4-triazine-3-amines, bis(trifluoromethyl)-2,3-dihydropyrazine-1,4-dioxides based on reactions of perfluorobiacetyl with bi- and trifunctional nucleophilic agents: urea, N - and N , N ′-substituted ureas, thiourea, thiosemicarbazide, semicarbazide hydrochloride, aminoguanidine bicarbonate, and N , N ′-dihydroxy-2,3-dimethylbutane-2,3-diamine. The reaction of 4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazilidin-2-one with urea in N , N -dimethylacetamide at elevated temperature afforded bis(trifluoromethyl)-glycoluril. Monosubstituted N -alkyl(aryl)-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-ones reacted with urea under similar conditions to give 1-alkyl(aryl)bis(trifluoromethyl)imidazooxazoles. The condensation reaction of trifluoromethyl-containing imidazolidin-2-ones(thiones) with thiourea and NH 4 SCN in a dipolar aprotic solvent at elevated temperature resulted in thioglycolurils, thioxoimidazothiazolones, and oxoimidazothiazolones. The first nitrogen-containing heterocycles containing a CF 3 group at the vicinal position to the N-O fragment were synthesized by the reaction of perfluorobiacetyl with N , N ′-dihydroxy-2,3-dimethylbutane-2,3-diamine.