Reactions of N-heteroarylformamide oximes and N-heteroarylacetamide oximes with N,N-dimethylformamide dimethyl acetal. Synthesis of 2-methyl-s-triazolo[1,5-x]azines and N-methylcyanoaminoazines

N-Heteroarylformamide oximes 3 (R ? H) were converted with N,N-dimethylformamide dimethyl acetal (DMFDMA) into N-heteroaryl-N-methylcyanoamino compounds 5 , as the main products. In some instances N-heteroarylcyanoamino compounds 4 , cyanoimino compounds 7 , and some other products, such as 9 and 10 were also formed. On the other hand, N-heteroarylacetamide oximes 3 (R ? CH₃) were cyclized under the same reaction conditions into 2-methyl-s-triazolo1,5-x]azines ( 6 ). N-Heteroarylacetamide O-methyl oximes 11 and 12 were prepared from the corresponding acetamidines 2 (R ? CH₃) and O-methylhydroxylamine.