Reactions of trifluoromethylated enamines with iminium chlorides and analogues. Synthesis of new 2-aza-1,3-dienes and pyridin-4-ones

The trifluoromethylated enamines 1 and 2 condense with monochloromethyleneiminium chlorides, N,N-dimethylacetamide dimethylacetal and chloroiminium chlorides prepared from lactams and gaseous phosgene to give the new 2-aza-1,3-dienes 5a-c, 6, 13a-f, 19a-c and 20a-c which then cyclize with sodium hydride to pyridin-4-ones 22 and 23a,b,e,f