Crystal structure of hydrazone form of 1-butyl-3-cyano-6-hydroxy-4-methyl-5-(2-thiazolylazo)-2-(1H)-pyridone

The structural results clearly indicate that 1-butyl-3-cyano-6-hydroxy-4-methyl-5-(2-thiazolylazo)-2(1H)-pyridone, (C14H15N5O2S) exists primarily as the hydrazone tautomer in the solid state. The molecule is nearly planar not regarding the butyl group. Some of the bond lengths and angles are distorted due to pi-electron delocalization and strain. A strong intramolecular N-H ... O hydrogen bond was found [N ... O = 2.53(1)Angstrom]. The crystallographic parameters are as follows: triclinic <P(1)over bar>, a = 5.972(4)Angstrom, b = 7.732(5)Angstrom, c = 17.348 (9) Angstrom, alpha = 85.62(5)degrees, beta = 79.24(6)degrees, gamma = 78.41(7)degrees, V = 770.4(9)Angstrom(3) Z=2, D-c = 1.37 g cm(-3), mu(MoKalpha) = 2.1 cm(-1), R = 0.045, G.O.F. = 1.78. Copyright (C) 1996 Elsevier Science Ltd