Synthesis, Crystal Structure and Biological Activity of Diethyl 1,4-dihydro-2,6-dimethyl-4-(4-methyl-1,2,3-thiadi azol-5-yl)pyridine-3,5-dicarboxylate

The title compound diethyl 1,4-dihydro-2,6-dimethyl-4-(4-methyl-1,2,3-thiadiazol-5-yl) pyridine-3,5-dicarboxylate (C16H21N3O4S, M-r = 351.42) was prepared by the Hantszch reaction with 4-methyl-1,2,3-thiadiazole-5-formaldehyde, ethyl acetoacetate and ammonium acetate in the presence of aluminum chloride in alcohol, and its structure was characterized by IR spectra, H-1-NMR, EA, and single-crystal X-ray diffraction. The crystal of the title compound belongs to monoclinic system, space group P2(1)/n with a = 11.300(2), b = 12.771(3), c = 12.826(3) angstrom, beta = 96.55(3)degrees, V = 1839.0(6) angstrom(3), Z = 4, D-c = 1.296 g/cm(3), mu(MoKa) = 0.71073 mm(-1), F(000) = 744, R= 0.0981 and wR = 0.1994. X-ray diffraction result shows that the torsion angles of N(1)-C(2)-C(3)-C(4) and C(2)-C(3)-C(4)-C(8) are 178.9(3) and 130.3(3), respectively. All rings in the title compound are non-planar. The bioassay results indicate that the title compound has good fungicidal activity, good antivirus activity against tobacco mosaic virus and certain extent of insecticidal activity against Mythimna separata.