The title compound N-tert-butyl-N-（4-methyl-1,2,3-thiadiazole）-5-yl-N＇-（4-me-thyl-1,2,3-thiadiazole）-5-formyl-N＇-3,5-dichloropyrid-2-yl-diacylhydrazines （C18H17Cl2N7O3S2, Mr = 514.41） has been synthesized by the reaction of N-tert-butyl-N＇-3,6-dichloropyridine-2-formyl hydrazine with 4-methyl-1,2,3-thiadiazole-5-carbonyl chloride and triethylamine, and its structure was characterized by 1H NMR, HR MS, and single-crystal X-ray diffraction. The crystal of the title compound belongs to monoclinic, space group C2/c with a = 27.726（8）, b = 11.045（3）, c = 14.507（4）A, β = 96.758（4）°, Z = 8, V = 4412（2） A^3, Dc = 1.549 g/cm^3, μ = 0.521 mm^-1, F（000） = 2112, R = 0.0405 and wR = 0.1153. X-ray analysis indicates that all rings are non-planar in this molecule. The bioassay results indicate that both the title compound and the positive control RH-5992 have weak fungicide activities, while the title compound has good insecticidal activity against Plutella xylostella L. and no insecticidal activity against Culex pipiens pallens.
The title compound naphthalen-2-yl-4-methyl-1,2,3-thiadiazole-5-carboxylate （C 14 H 10 N 2 O 2 S,M r=270.31） was synthesized by the reaction of 4-methyl-1,2,3-thiadiazole-5-carbonyl chloride with 2-naphthol,and its structure was characterized by IR,1 H NMR,high-resolution mass spectrometry and single-crystal X-ray diffraction.The crystal belongs to orthorhombic,space group Pbcn with a=23.475（5）,b=9.6640（19）,c=10.814（2）,β=90.00°,Z=8,V=2453.2（9） 3,M r=270.30,D c=1.464 g/cm 3,μ=0.262 mm-1,F（000）=1120,R=0.0444 and wR=0.1099.X-ray analysis revealed that the thiadiazole and naphthalene rings were non-planar,while the thiadiazole ring and the ester group were essentially planar,and two intermolecular hydrogen bonds C（6） H（6）···O（1） and C（14） H（14）···O（1） were observed.The preliminary biological test showed that the title compound had antifungal and antivirus activities against tobacco mosaic virus.
