1H-四氮唑乙酸的合成

以水合肼、单氰胺为起始原料,以85%收率合成5-氨基四氮唑;然后,发生去氨基还原反应,以95%收率得到1H-四氮唑;最后,在碱性条件下与氯乙酸发生亲核取代反应,以81.7%收率合成了1H-四氮唑乙酸。该合成路线均采用水作为反应媒介,总收率高于65%。重点针对1H-四氮唑的亲核取代反应进行优化,得出较佳工艺条件:反应温度为100℃,物料配比为n(1H-四氮唑)∶n(ClCH2COOH)∶n(NaHCO3)=1∶1∶2.2,反应时间为20 h。

Synthesis of 1H-Tetrazole Acetic Acid

A novel process of preparing 1H-tetrazole acetic acid is reported in this paper.Firstly,5-amino tetrazole was synthesized from hydrazine hydrate and cyanamide with a yield of 85%.Then,the intermediate was subjected to the second step of deamination reaction to give 1H-tetrazole with the yield of 95%.The last step was for 1H-tetrazole to go through nucleophilic substitution with chloroacetic acid.Under basic conditions,1H-tetrazole acetic acid was produced from 1H-tetrazole and chloroacetic acid with a yield of 81.7%.Water was used as the reaction medium in the above steps,and the total yield of 1H-tetrazole acetic acid was higher than 65%.The key focus of this paper was the optimization of nucleophilic substitution,and the optimum conditions were ascertained as follows:reaction temperature 100 ℃,n(1H-tetrazole)∶ n(ClCH2COOH)∶ n(NaHCO3)=1∶ 1∶ 2.2,reaction time 20 h.