Synthesis and structure of p-chlorophenylhydrazone of 3-(methylthio)-5-propanoyl-1,2,4-triazine

The reaction of 3-(methylthio)-5-propanoyl-1,2,4-triazine with p-chlorophen ylhydrazine hydrochloride is completed within 5 min at room temperature in ethanol leading to p-chlorophenylhydrazone of 3-(methylthio)-5-propanoyl-1, 2,4-triazine 1 in good yield. Title compound, 1 (R = C2H5, R-1 = Cl, Z = SC H3), C13H14N5SCl, crystallizes in the monoclinic system, space group P2(1)/ n, with cell constants a = 12.5206(6) Angstrom, b = 9.3122(8) Angstrom, c = 12.8524(9) Angstrom, and beta = 98.822(5)degrees, Z = 4, T = 293 K, D-cal = 1.381 g cm(-3). The structure was solved by direct methods and refined to R value of 0.0671 for 1,679 reflections. The molecule as a whole has an al most planar conformation and possesses (E) configuration with respect to th e C=N double bond. The crystal structure is stabilized by a weak N(13)-H(13 ). . .N(2) intermolecular hydrogen bond and significant stacking, character istic for pi -electron systems.