盐酸非那吡啶的合成及其热稳定性初步研究

Preparation and thermostability of phenazopyridine hydrochloride

目的研究盐酸非那吡啶的制备工艺及其热稳定性。方法以苯胺为原料,经重氮化、偶合、中和、成盐得盐酸非那呲啶;用热重分析法(TG)和差示扫描量热法(DSC)对其热稳定性进行初步研究。结果本工艺路线4步总收率为71.5%;在氮气氛(氮气流量为20 mL.min-1)、10 K.min-1的升温条件下,将盐酸非那吡啶加热到235℃才开始发生剧烈分解,至287.4℃时,有50.79%的盐酸非那呲啶发生分解。结论本制备方法简单,适合于大量制备。本品的热稳定性较好。

OBJFCTIVE To study the preparation and thermostability of phenazopyridine hydrochloride. METHODS Phenazopyridine hydrochloride was obtained by successive diazotization, coupling reaction, neutralization and salt formation, starting from aniline. Its thermostability was investigated by differential scanning calorimetry and thermogravimetry. RESULTS The overall yield of the step process of phenazopyridine hydrochloride from the aniline was 71.5%. The experiments showed that, in nitrogen with a heating rate of 10 K · min ^-1 , the solid of phenazopyridine hydrochloride could produce an intense thermolysis at up to 235 ℃. There would be 50.79% of Phenazopyridine hydrochloride that was decomposed when the temperature rose to 287.4 ℃. CONCLUSIONS It is convenient and suitable for large scale preparation. Phenazopyridine hydrochloride is thermostable.