Hydrogen-bonded chains of rings in methyl 4-[(5-methyl-1H-pyrazol-3-yl)amino]-3-nitrobenzoate and hydrogen-bonded sheets in methyl 1-(5-methyl-1H-pyrazol-3-yl)-1H-benzimidazole-5-carboxylate

Abstract

Molecules of methyl 4-[(5-methyl-1H-pyrazol-3-yl)amino]-3-nitrobenzoate, C12H12N4O4, (I), exhibit a polarized (charge-separated) structure in the nitroaniline portion. The molecules are linked into chains of edge-fused R(2)2(16) and R(2)2(22) rings by a combination of N-H...O(carbonyl) and C-H...O(nitro) hydrogen bonds. Methyl 1-(5-methyl-1H-pyrazol-3-yl)-1H-benzimidazole-5-carboxylate, C13H12N4O2, (II), which is readily formed from (I) by reduction followed by ring formation, crystallizes with Z' = 2 in the space group P-1. Each of the two independent molecular types is linked into sheets of R(4)4(28) rings by a combination of N-H...N and C-H...O(carbonyl) hydrogen bonds.