Synthesis,Crystal Structure and Antifungal Activity of New Furan-1,3,4-oxadiazole Carboxamide Derivatives

A series of novel furan-1,3,4-oxadiazole carboxamide derivatives (5a~5e) were designed,synthesized and characterized by spectroscopic methods including HR-MS,^(1)H-and ^(13)C-NMR.The crystal structure of compound 5a was determined by single-crystal X-ray diffraction.The compound crystallizes in the triclinic system,space group P■ with a=4.7261(5),b=10.4672(11),c=14.5886(13)?,α=106.081(4)°,β=91.043(3)°,γ=99.456(4)°,Z=2,V=682.48(12)?^(3),M_(r)=348.16,D_(c)=1.694 Mg/m^(3),S=1.008,m=3.025 mm^(-1),F(000)=348,the final R=0.0775 and w R=0.2080 for 2774 observed reflections (I (29) 2σ(I)).There are two kinds of hydrogen bonds (N(3)–H(3A)×××N(2) and C(8)–H(8A)×××O(3)) present in its crystal structure.The preliminary antifungal assay showed that compounds 5b and 5c exhibited significant antifungal activities against several plant pathogenic fungi.