邻羧基苯肼盐酸盐的合成工艺研究

A Practical Synthesis Route of 2-Hydrazinobenzoic Acid Hydrochloride

本文以邻氨基苯甲酸为原料,经重氮化后,在表面活性剂PEG-600和少量锌粉存在下,70℃时经亚硫酸钠还原、20～25%的盐酸酸析后制得邻羧基苯肼盐酸盐,产率83.4%,含量(HPLC)≥99.5%,邻氨基苯甲酸:亚硝酸钠:盐酸:亚硫酸钠为1.0:1.02:3.0:2.5(mol/mol),邻氨基苯甲酸:PEG-600:锌粉为1.0:0.02:0.05(W/W)。

In this paper, 2-hydrazinobenzoic acid hydrochloride was synthesized from 2-amino benzoic acid through diazotization, Na2SO3 reduction methods. The 2-amino benzoic acid was at first diazotized in dilute hydrochloride acid and PEG-600, then the solution of diazohium hydrochloride was droped into Na2SO3 solution at 70℃, it was reduced, and then acided in 20～25% of hydrochloride acid, the yield was above 83.4%, assay ≥99.5%, by HPLC. It was in keeping with the standard by elemental analysis and mass spectrometry. The practical synthesis route were 2-amino benzoic acid ： sodium nitrite ： hydrochloride acid ： sodium sulfite was 1.0 ： 1.02 ： 3.0 ： 2.5（ mol/ mol）, 2-amino benzoic acid ： PEG-600 ： Zn was 1.0 ： 0.02 ： 0.05（W/W）.