Synthesis, Crystal Structure and Biological Activity of N-(2,6-Difiuorobenzoyl)-N'-[5-(4-trifiuoromethylphenyl)-1,3,4-thiadiazol-2-yl] ure

The title compound N-(2,6-difluorobenzoyl)-N'-[5-(4-trifluoromethylphenyl)-1,3,4-thiadiazol-2-yl]urea(C17H9F5N4O2S, Mr = 428.34) has been synthesized by the reaction of 2-amino-5-(4-trifluoromethylphenyl)-l,3,4-thiadiazole with 2,6-difluorobenzoyl isocyanate, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 10.7316(13), b = 10.5617(13), c = 16.037(2) (A), β =106.408(2)°, V= 1743.6(4) (A)3, Z = 4, Dc = 1.632 g/cm3, μ = 0.260 mm-1, F(000) = 864, the final R = 0.0599 and wR = 0.1420 for 3467 observed reflections with I ＞ 2o(Ⅰ). The urea group, which adopts a planar configuration mediated by the intramolecular N-H…O hydrogen bond, is nearly coplanar with the thiadiazole and 4-trifluoromethylbenzene rings. The title compound was found to exhibit good fungicidal activity against Rhizoctonia solani and Botrytis cinerea.