Two isomeric reaction products: hydrogen-bonded sheets in methyl 4-(5-amino-3-phenyl-1H-pyrazol-1-yl)-3-nitrobenzoate and hydrogen-bonded chains of edge-fused rings in methyl 3-nitro-4-[(5-phenyl-1H-pyrazol-3-yl)amino]benzoate.

In methyl 4-(5-amino-3-phenyl-1H-pyrazol-1-yl)-3-nitrobenzoate, C(17)H(14)N(4)O(4), the molecules are linked into complex sheets by a combination of N-H...N, N-H...O and C-H...O hydrogen bonds. In the isomeric methyl 3-nitro-4-[(5-phenyl-1H-pyrazol-3-yl)amino]benzoate, molecules exhibit a polarized molecular-electronic structure and are linked into chains of edge-fused rings by a combination of N-H...O and C-H...O hydrogen bonds.