5-氨基-1,2,3-噻二唑的合成

Synthesis of 5-Amino-1,2,3-Thiadiazoles

介绍了以碳酸二甲酯、水合肼和氯乙醛为原料通过系列反应合成5氨基1,2,3噻二唑的方法.对每步反应的合成条件进行了优化,由起初设计的4步反应改进为3步,并用水蒸气蒸馏分离出中间体5氯1,2,3噻二唑,纯度达99%(气相色谱法),得到的中间体直接下一步反应,最后采用混合溶剂氯仿∶乙醇(V/V)=4∶1重结晶,得到产品熔点为138～139℃,反应总收率达40%以上.

5-Amino-1,2,3-thiadiazoles can be composed through a series of reactions of diethyl carboxylate, hydrazine hydrate and chloroacetaldehyde. The synthetic conditions of each step are optimalized—the 4 step method of intermediate 5-chloro-1,2,3-thiadiazole is shortened to a 3 step method, and steam distillation is improved. The purity reached 99% (by GC). The product 5-amino-1,2,3-thiadiazoles can be obtained from chloroform∶ethyl alcohol (V/V)= 4∶1, mp:138~139℃, the overyield is about 40%.