采用盐酸法、三氟乙酸法分别制备邻硝基苯胺重氮盐;首先对比分析了盐酸、三氟乙酸对邻硝基苯胺的溶解性,通过对重氮液UV-vis光谱峰型、峰高的分析,探讨了储存时间、温度、pH条件对重氮液稳定性的影响。实验证明:三氟乙酸可在0~5℃,20min内完全溶解邻硝基苯胺;同时三氟乙酸法制备邻硝基苯胺重氮盐溶液在15℃、pH6的条件下具有较好的稳定性。
Hydrochloric acid and trifluoroacetic acid were used to prepare o-nitroaniline diazonium salt. First of all, contrastive analysis of the solubility of hydrochloric acid, trifluoroacetic acid for o-nitroaniline was carried out. The influences of storage time, temperature and pH on the stability of the diazonium solution were discussed through analysis of UV-vis spectra peak and peak height of the diazonium solution. The experiment shows that trifluoroacetic acid can dissolve o-nitroaniline well within 20 min under 0~5℃ meanwhile, o-nitroaniline diazonium salt solution prepared with trifluoroacetic acid has good stability under the conditions of 15℃ and pH 6.