Synthesis And Antifungal Activity Of New Methoxy Acrlates Containing 1,2,4-Thiadiazole

Strobilurins (methoxy acrylates) have been widely used and gained increasingly attention in the pesticide field for their advantages of low-toxicity, high efficiency, broad spectrum and systemic,and are possessing great potential for growth. Methyl(5-amino-1,2,4-thiadiazol-3-yl) (methoxyimino) ethanoate, as a methoxy acrylate compound that contains 1,2,4-thiadiazole,is a indispensable active intermediate of 4th generation cephalosporin-Cefozopran which is mainly used in medicine, but in the field of pesticide has not been developed and applied. During this study,the 1,2,4-thiadiazole heterocycle will be introduced to methoxy acrylates in order to find efficient leading compounds to develop new agricultural fungicides meeting the demand of current society。Methyl(5-amino-1,2,4-thiadiazol-3-yl)(methoxyimino)ethanoate (compound 6), N-meth- yl(5-amino-1,2,4-thiadiazol-3-yl)(methoxyimino) acetamide (compound 7) and their 34 amides derivatives were synthesized from methyl cyanoacetate, all the compounds are firstly reported except compound 6.Each structure was characterized by 1~H-NMR and ESI-MS,and some were by IR or (13)~C-NMR additionally.Antifungal activity test showed as fowllows:all the 36 compounds have differernt inhibitory effect against the six tested strains at the concentration of 100 mg/L. Overall, fungicidal activity of amide derivatives from compound 6 are obviously higher than that of 7. To the derivatives from compound 6, aromatic amide derivatives have higher fungicidal activity than aliphatic ones, especially the one contains heteroatoms such as F, Cl, et al.like 6o,6p,6n,6q and 6u, which exhibit strong average inhibiting effect,and give the inhibition rate more than 50%, of them 6n shows the best, with the average inhibition rate reached 63%; activity to significantly including derivatives such as the miscellaneous atoms of aromatic compounds In addition , 7c and 7k give special effect on Glomerella cingulata with 100% inhabitation,and as the same 6r against Fusarium graminearum.