Preparation of novel trifluoroacetylketene O,N-acetals and trifluoromethyl-containing S,S-sulfoximido N-substituted heterocycles

two new trifluoroacetylketene o,n-acetals [cf3c(o)ch=c(oet)(ns(o)r2), where r = ch3, ph] derived from the reaction of 4,4-diethoxy-1,1,1-trifluorobut-3-en-2-one [cf3c(o)ch=c(oet)2] with s,s-dimethyl- and s-methyl-s-phenyl-sulfoximide [hn=s(o)r2], in the presence of triethylamine, have been obtained, in 60-72% yields, and applied in the synthesis of s,s-dimethylsulfoximido-substituted pyrazoles, isoxazoles and pyrimidines, in 55-89% yields, from the reactions of 4-ethoxy-4-(s,s-dimethylsulfoximido)-1,1,1-trifluorobut-3-en-2-one with hydrazines, hydroxylamine hydrochloride and acetylguanidine.