2-氨基-1,3,4-噻二唑合成新工艺及优化

甲酸与硫代氨基脲以催化活性较高的氢溴酸催化剂合成了2-氨基-1,3,4-噻二唑,并通过响应曲面法对催化剂的投加量、反应温度、反应时间等因素进行了优化及分析,得出了2-氨基-1,3,4-噻二唑合成的最佳工艺条件:甲酸与硫代氨基脲的摩尔比为1.2∶1,氢溴酸20mL(硫代氨基脲为0.022mol),反应时间为4.6h,反应温度为104℃,产率为74.44%.将得到的最佳工艺条件应用于乙酸、丙酸、正丁酸、正戊酸、氯乙酸等与硫代氨基脲合成2-氨基-1,3,4-噻二唑的反应中同样获得了较高产率,产率分别为70.08%,78.72%,78.72%,66.77%,72.11%.

Optimization of new technology for preparation of 2-amino-1,3,4-thiadiazole

2-amino-1 ,3 ,4-thiadiazole was prepared by fortic acid with thiosemicarbazide in the presence of hydrobromic acid with higher catalytic activity ,and the process was optimized perfectly through the analysis of catalyst dosage ,reaction temperature and reaction time by response surface methodology .The target compound synthesis of the best process as follows ：the molar ratio of fortic acid and thiosemicarbazide is 1 .2∶1 ,and hydrobromic acid dosage of 20 mL （thiosemicarbazide was 0 .022 mol） ,the reaction time 4 .6 h ,the reaction tempera-ture is 104 ℃ ,under the optimal conditions ,the yield was 74 .44% .Synthesis of other 2-a-mino-1 ,3 ,4-thiadiazole by acetic acid ,propionic acid ,n-butyric acid ,n-valeric acid ,chloro-acetic acid with thiosemicarbazide afforded higher yield under this optimal conditions ,the yield w as 70 .08% ,78 .72% ,78 .72% ,66 .77% ,72 .11% respectively .