无水氨苄西林的制备及其反应机理分析

Preparation and Reaction Mechanism Analysis of Anhydrous Ampicillin

通过溶剂热方法制备了无水氨苄西林,借助料浆pH变化规律来判断氨苄西林脱水终点,并对氨苄西林脱水机理和脱水动力学模型进行了初步分析。本文主要考察氨苄西林在8%、15%、20%、25%水分异丙醇溶剂中的脱水情况,不同水分情况下料浆pH均出现了“缓降阶段→骤降阶段→平缓阶段”,平缓阶段pH变化率和ΔpH均可以判断氨苄西林的脱水终点。脱水动力学研究结果表明:氨苄西林脱水表观动力学符合0.5级反应,拟合度R^(2)=0.99746。

Anhydrous ampicillin was prepared by solvent thermal method,and the dehydration endpoint of ampicillin was determined by the pH change law of the slurry.the dehydration mechanism and kinetics model of ampicillin were preliminarily analyzed.This article mainly investigates the dehydration of ampicillin in isopropanol solvents with 8%,15%,20%and 25%moisture content.Under different moisture conditions,the pH of the slurry exhibits a"gradual decrease stage→sudden decrease stage→gentle stage",the rate of pH change during the gentle stage andΔpH can be used to determine the dehydration endpoint of ampicillin.The results of dehydration kinetics research indicate that the apparent kinetics of ampicillin dehydration follows a 0.5 order reaction,with a fitting degree of R^(2)=0.99746.