A hydrogen-bonded chain of rings in 5-amino-1-(4-methoxybenzoyl)-3-methylpyrazole and a three-dimensional hydrogen-bonded framework in 5-amino-3-methyl-1-(2-nitrobenzoyl)-pyrazole

The molecules of 5-amino-1-(4-methoxybenzoyl)-3-methylpyrazole, C12H13N3O2, (I), and 5-amino-3-methyl-1-(2-nitrobenzoyl) pyrazole, C11H10N4O3, (II), both contain intramolecular N-H center dot center dot center dot O hydrogen bonds. The molecules of (I) are linked into a chain of rings by a combination of N-H center dot center dot center dot N and N-H center dot center dot center dot pi(arene) hydrogen bonds, while those of (II) are linked into a three-dimensional framework structure by N-H center dot center dot center dot N and C-H center dot center dot center dot O hydrogen bonds.