1H-四氮唑乙酸的合成

Synthesis of 1H-Tetrazole Acetic Acid

摘要:

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。此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。

Abstract:

A novel process of preparing 1H-tetrazole acetic acid was reported in this paper. Firstly, 5-amino tetrazole was synthesized in 85% yield from hydrazine hydrate and cyanamide. The second step was deamination reaction (the yield was 95%). The last step was nucleophilic substitution. Under basic condition, 1H-tetrazole acetic acid was produced by 1H-tetrazole and chloroacetic acid in 81.7% yield. Water was used as the reaction medium in the above steps. The total yield of 1H-tetrazole acetic acid was higher than 65%. In this paper, the most important work focused on the optimization of nucleophilic substitution. The better conditions for this substitution: reaction temperature 100 ℃, n(1H-tetrazole):n(ClCH2COOH):n(NaHCO3)＝1:1:2.2, the reaction time 20 h.