2-Arylhydrazononitriles in heterocyclic synthesis: A novel route to 1,3-diaryl-1,2,4-triazol-5-amines via a Tiemann rearrangement of arylhydrazonoamidoximes
- H. M. Al-Matar, S. M. Riyadh, M. H. Elnagdi
Benzylcyanide and 4-nitrobenzylcyanide condensed with triethyl orthoformate and piperidine or morpholine to yield 2-aryl-2-piperidinyl or 2-morpholinylacrylonitriles. These coupled with aromatic diazonium salts to yield the 2-arylhydrazno-2-arylethane nitriles in good yields. The latter were converted into 4-aminopyrazoles in good yields using the Thorpe-Ziegler cyclization.