管道化氨解合成对乙酰氨基酚新工艺

Synthesis of p-Acetylaminophenol with Pipeline Reactor

关键词:  对乙酰氨基酚  对硝基苯酚钠  管道化  氨解

Key words:  p-acetylaminophenol  p-nitrophenol sodium  pipeline reactor  amination

摘要:

目的 采用管道化氨解工艺合成对乙酰氨基酚。方法 将对硝基苯酚钠的40%水溶液、液氨及催化剂氯化铵的1%水溶液以体积流量比9.25∶1∶1.85经预混合器后以0.15 mL·s^-1的总流量流经外径6 mm，内径3 mm，总长50 m的管道反应器进行反应，反应温度220 ℃，反应压力6.0 MPa，反应停留时间40 min，脱除溶剂重结晶后得对氨基苯酚钠固体，再经酸化、乙酰化后得到对乙酰氨基酚。结果 得到的对乙酰氨基酚熔点167~169 ℃，三步总收率72.7%。结论 新工艺避免了还原步骤，减少了环境污染，安全性好，反应条件容易控制，并能得到良好的反应效果。

Abstract:

OBJECTIVE To prepare p-aminophenol sodium based on p-nitrophenol sodium by amination in pipeline reactor. METHODS The solution mixed with 40% p-nitrophenol sodium solution-ammonia-1% ammonium chloridesolution solution(9.25∶1∶1.85) passed through the pipeline reactor(6 mm×3 mm×50 m) at the speed of 0.15 mL·s^-1　for 40 min with the temperature of 220 ℃, pressure of 6.0 MPa. Then p-nitrophenol sodium was prepared by the solution via desolventize, recrystallization, acidification and acetylation. RESULTS The melting point of p-aminophenol sodium achieved was 167-169 ℃, and the total yield was 72.7%. CONCLUSION The new process avoids the reduction step, reduces environmental pollution, and is more safety, controllable and the results are better than the normal process.