1. Synthesis of nitrogen-containing heterocycles. II. Cyclization of diaminomethylenehydrazones with ethoxymethylene compounds.
2. Synthesis of nitrogen-containing heterocycles. 4. A facile route to new 1, 2, 4-triazole derivatives
3. The carbonyl frequencies in the internal (ir) spectra of 3 appears in the range of 1690-1675 cm−1, which corresponds to the internally bonded bands of the bis(ethoxycarbonyl)vinylamino compounds 4. Thus the geometry about the CH=C bond of 3 should be Z form.