Department of Chemistry, Xihua University, Chengdu 610039, China.
Asymmetric Synthesis and Chiral Technology Key Laboratory of Sichuan Province, Yibin 644000, China.
Molecules. 2022 Aug 12;27(16):5139. doi: 10.3390/molecules27165139.
An efficient continuous-flow nitration process of -xylene at pilot scale was demonstrated. The effects of parameters such as temperature, ratio of HSO to HNO, HSO concentration, flow rate, and residence time on the reaction were studied. Under the optimal conditions, the yield of products reached 94.1%, with a product throughput of 800 g/h. The main impurities of this continuous-flow nitration process were also studied in detail. Compared with batch process, phenolic impurity decreased from 2% to 0.1%, which enabled the omission of the alkaline solution washing step and thus reduced the wastewater emission. The method was also successfully applied to the nitrification of -xylene, toluene, and chlorobenzene with good yields.
采用连续流硝化工艺在中试规模下对间二甲苯进行了高效硝化。研究了温度、HSO/HNO 摩尔比、HSO 浓度、流速和停留时间等参数对反应的影响。在最佳条件下，产物收率达到 94.1%，产品的处理量为 800 g/h。还详细研究了该连续流硝化工艺的主要杂质。与间歇工艺相比，酚类杂质从 2%降低至 0.1%，这使得可以省略碱性溶液洗涤步骤，从而减少废水排放。该方法还成功地应用于间二甲苯、甲苯和氯苯的硝化，收率良好。
