Synthesis, spectroscopic and structural studies of 4-Amino-3-(ethyl)-5-(4-chlorophenyl)-4H-1,2,4-triazole and 4-Amino-3-cyclopropyl-5-oxo-4,5-dihydro-1,2,4-triazole-1-yl-acetic acid ethyl ester

The title compounds of 4-Amino-3-(ethyl)-5-(4-chlorophenyl)-4H-1,2,4-triazole (I, C10H11ClN4) and 4-Amino-3-cyclopropyl-5-oxo-4,5-dihydro-1,2,4-triazol-1-yl-acetic acid ethyl ester (II, C9H14N4O3), have been determined using X-ray diffraction techniques and characterized by IR, 1H NMR and 13C NMR. X-ray study shows that the title compounds both have strong intermolecular NH⋯N hydrogen bonds. The molecules of I are linked into a two-dimensional framework structure by NH⋯N and CH⋯N hydrogen bonds which produce R22(8)R44(14)R44(15) chain of rings, while in II, the combination of NH⋯N, NH⋯O and CH⋯O hydrogen bonds along [1 0 0] generates a chain of edge-fused R22(10)R22(16)R42(14) R44(14) rings.