The title compound (C20H15ClN4O, Mr = 362.81) was synthesized by the reaction of ethyl 2-cyano-3-(2-chlorophenyl)-1-acylate with 5-amino-3-methyl-1-phenylpyrazole under microwave irradiation and its structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 8.8192(19), b = 15.976(3), c = 13.094(3) ? = 103.074(4), V = 1797.1(7) ?, Z = 4, Dc = 1.341 g/cm3, = 0.229 mm-1, F(000) = 752, R = 0.0632 and wR = 0.1278. X-ray analysis reveals that the pyridine ring adopts an envelope conformation. The dihedral angle between the pyrazole and pyridine planes is 2.19, and inter- molecular hydrogen bonds are also observed in the molecule. The title compound (C20H15ClN4O, Mr = 362.81) was synthesized by the reaction of ethyl 2-cyano-3- (2-chlorophenyl) -1-acylate with 5-amino-3-methyl- 1 -phenylpyrazole under microwave irradiation and its structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic space group P21 / n with a = 8.8192 (19), b = 15.976 (3), c = 13.094 V = 1797.1 (7) ?, Z = 4, Dc = 1.341 g / cm3, = 0.229 mm-1, F (000) = 752, R = 0.0632 and wR = 0.1278. an envelope conformation. The dihedral angle between the pyrazole and pyridine planes is 2.19, and inter- molecular hydrogen bonds are also observed in the molecule.