Novel 2H-1,2,3-Triazole Sodium Complex from N-[2-Amino-1,2-dicyanovinyl]alkanamides

Diazotization at 0 o C of N-[2-amino-1,2-dicyanovinyl]ethanamide 2aor propanamide 2b prepared from diaminomaleonitrile (DAMN) 1 using aqueous acetic acid and NaNO 2 solution furnished sodium complex 3.The X-ray structure of the complex 3 showed that it is a 1:1 mixture of the neutral 2H-triazole heterocycle 4ii and its anion deprotonated at the central (N) atom of the ring, together with a sodium counter ion and two coordinated water molecules.However, when the diazotization reaction was carried out in the presence of aqueous HCl, the product was 5-cyano-2H-[1,2,3]triazole-4-carboxylic acid amide monohydrate 4ii.Diazotization of DAMN 1 using aqueous HCl furnished 1H-1,2,3-triazole-4,5-dicarbonitrile 5, whereas with acetic acid there was no reaction, and hence no route analogous to that leading to complex 3.The structure of both complex 3 and the triazole monohydrate 4ii were solved using X-ray crystallography, and the compounds under study were fully characterized using spectroscopic techniques.