噻吩甲酰硫脲衍生物的合成及其抑菌活性

Synthesis of Thiophene Formyl Thiourea Derivatives and Fungicidal Activity

通过3-巯基-2-丁酮与取代硅基丙炔酸甲酯的环合、酯的选择性水解、异硫氰化、胺化等步骤合成了13个未见报道的噻吩甲酰硫脲衍生物.各噻吩甲酰硫脲衍生物的结构经~1H NMR、^(13)C NMR和元素分析的确证,其对小麦全蚀病、水稻纹枯病病原菌的抑菌活性经平皿法进行了测试.结果表明,大部分噻吩甲酰硫脲衍生物对小麦全蚀病病原菌具有一定抑制活性,其中1-环丙基-3-(4,5-二甲基噻吩-3-甲酰基)硫脲(8c)抑菌活性表现较为突出,在10 mg/L浓度下其抑菌活性接近对照硅噻菌胺的水平.结构分析表明噻吩-3-甲酰硫脲衍生物噻吩环2位官能团的大小对小麦全蚀病菌抑制活性的影响不明显.

13 New thiophene formyl thiourea derivatives were synthesized via cycloaddition reaction of 3-mercaptobutan-2-one and methyl 3-（substitutedsilyl）propiolate, selective hydrolysis of ester, isothiocyanatation and amination. Their chemical structures were confirmed by 1H NMR, 13C NMR and elemental analysis. The inhibitory activity against Gaeumannomyces graminis var. tritici and Rhizoctonia solani was evaluated in vitro by the plate method. The results indicated that most of thiophene formyl thiourea derivatives showed some inhibitory activity against gaeumannomyces graminis var. tritici. Compound 1-cyclopropyl-3-（4,5-dimethylthiophene-3-carbonyl）thiourea （8c） gave the best performance and its inhibitory activity was close to the control level of silthiopham in the concentration of 10 mg/L. The structure analysis showed that the steric hindrance of functional group at the second position of the thiophene formyl thioureas had no obvious effect on the inhibitory activity against gaeumannomyces graminis var. tritici.