Microwave-assisted Synthesis and Crystal Structure of 3-Acetamido-1-phenyl-4-(2,6-dichloro)benzylidene-5-pyrazolone

The title compound, 3-acetamido-1-phenyl-4-(2,6-dichloro)benzylidene-5-pyrazolone (C(18)H(13)Cl(2)N(3)O(2), M(r) = 374.21), has been synthesized by one-step condensation of 2,6-dichlorobenzaldehyde with acetic anhydride and 3-amino-1-phenyl-5-pyrazolone under microwave irradiation. The compound was characterized by means of IR and (1)H NMR. Its crystal and molecular structure were determined by X-ray diffractometry. It belongs to the orthorhombic system, space group Pbca, with a = 12.5312(13), b = 8.5495(9), c = 31.110(3) angstrom, V = 3332.9(6) angstrom(3), Z = 8, D(c) = 1.492 g/cm(3), lambda = 0.71073 angstrom, mu(MoK alpha) = 0.407 mm(-1), F(000) = 1536, the final R = 0.0394 and wR = 0.0984. A total of 15894 reflections were collected, of which 3630 were independent (R(int) = 0.0362). There exist three planes in the molecular structure. X-ray analysis reveals that the dihedral angles between planes 1 and 2, 1 and 3 and 3 and 2 are 80.89, 74.29 and 20.57 degrees, respectively.