Preparation,Crystal Structure and Fungicidal Activity of N-(5-(benzofuranol-7-oxymethyl)-1,3,4-thiadiazol-2-yl)amide Compounds

A variety of new N-(5-(benzofuranol-7-oxymethyl)-1,3,4-thiadiazol-2-yl)amide compounds(8a-i)were synthesized through four steps from benzofuranol as raw materials.The crystal structure of compound 8a(C17H21N3O3S,Mr=347.43)was measured by X-ray diffraction,which was classified as monoclinic system,Z=4,V=1742.72(8)Å3,Dc=1.324 Mg/m3,F(000)=736,S=1.03,μ=0.21 mm-1,space group P21 with a=9.9177(3),b=8.9519(2),c=19.8679(5)Å,the final R=0.035 and wR=0.105 for 3873 observed reflections(I>2σ(I)).The X-ray structure presented N(3)-H(3)···N(2)and C(6)-H(6)···O(3)intermolecular hydrogen bonds,which acted as an important role in stabilizing the crystal structure.Additionally,preliminary biological assay on compound 8a showed good fungicidal activity in vivo,with the inhibition of 75%against Pseudoperonospora cu-bensis at 200 mg/L.