对氯苯肼盐酸盐的连续化合成工艺研究

Continuous Synthesis of p-Chlorophenylhydrazine Hydrochloride

以对氯苯胺为原材料,采用管式反应器进行重氮化、还原和酸化反应来合成对氯苯肼盐酸盐。系统地考查了重氮化、还原及酸化反应中原材料的浓度、停留时间及温度的影响,筛选出合适的反应条件。重氮化反应的最优条件为:对氯苯胺溶液浓度为15%,停留时间20 s,温度为0℃～10℃;还原反应的最优条件为:亚硫酸钠溶液浓度为20%,停留时间25 s,温度70℃;还原反应的最优条件为:盐酸浓度为20%,停留时间50 s,温度80℃。该工艺实现了对氯苯肼盐酸盐的连续化合成,安全性好,收率高,适合工业化生产。

p-Chlorophenylhydrazine hydrochloride was synthesized from p-chloroaniline by diazotization,reduction and acidification in a tubular reactor.The effects of raw material concentration,residence time and temperature on diazotization,reduction and acidification were systematically investigated,and appropriate reaction conditions were selected.The optimum conditions for diazotization are as follows:the concentration of p-chloroaniline solution is15%,the residence time is20s,the temperature is0~10℃,the optimum conditions for reduction reaction are as follows:the concentration of sodium sulfite solution is20%,the residence time is25s,the temperature is70℃,the optimum conditions for reduction reaction are as follows:the concentration of hydrochloric acid is20%,the residence time is50s,and the temperature is80℃.The process realizes the continuous synthesis of p-chlorophenylhydrazine hydrochloride with high safety and yield,and is suitable for industrial production.