Continuous-Flow Synthesis of Nitro-o-xylenes: Process Optimization, Impurity Study and Extension to Analogues

An efficient continuous-flow nitration process of o-xylene at pilot scale was demonstrated. The effects of parameters such as temperature, ratio of H(2)SO(4) to HNO(3), H(2)SO(4) concentration, flow rate, and residence time on the reaction were studied. Under the optimal conditions, the yield of pro...

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Autores principales: Song, Qiao, Lei, Xiangui, Yang, Sheng, Wang, Sheng, Wang, Jianhui, Chen, Jiujun, Xiang, Yong, Huang, Qingwu, Wang, Zhouyu
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Article
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9416712/
https://www.ncbi.nlm.nih.gov/pubmed/36014379
http://dx.doi.org/10.3390/molecules27165139
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author Song, Qiao
Lei, Xiangui
Yang, Sheng
Wang, Sheng
Wang, Jianhui
Chen, Jiujun
Xiang, Yong
Huang, Qingwu
Wang, Zhouyu
author_facet Song, Qiao
Lei, Xiangui
Yang, Sheng
Wang, Sheng
Wang, Jianhui
Chen, Jiujun
Xiang, Yong
Huang, Qingwu
Wang, Zhouyu
author_sort Song, Qiao
collection PubMed
description An efficient continuous-flow nitration process of o-xylene at pilot scale was demonstrated. The effects of parameters such as temperature, ratio of H(2)SO(4) to HNO(3), H(2)SO(4) 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 p-xylene, toluene, and chlorobenzene with good yields.
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spelling pubmed-94167122022-08-27 Continuous-Flow Synthesis of Nitro-o-xylenes: Process Optimization, Impurity Study and Extension to Analogues Song, Qiao Lei, Xiangui Yang, Sheng Wang, Sheng Wang, Jianhui Chen, Jiujun Xiang, Yong Huang, Qingwu Wang, Zhouyu Molecules Article An efficient continuous-flow nitration process of o-xylene at pilot scale was demonstrated. The effects of parameters such as temperature, ratio of H(2)SO(4) to HNO(3), H(2)SO(4) 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 p-xylene, toluene, and chlorobenzene with good yields. MDPI 2022-08-12 /pmc/articles/PMC9416712/ /pubmed/36014379 http://dx.doi.org/10.3390/molecules27165139 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Song, Qiao
Lei, Xiangui
Yang, Sheng
Wang, Sheng
Wang, Jianhui
Chen, Jiujun
Xiang, Yong
Huang, Qingwu
Wang, Zhouyu
Continuous-Flow Synthesis of Nitro-o-xylenes: Process Optimization, Impurity Study and Extension to Analogues
title Continuous-Flow Synthesis of Nitro-o-xylenes: Process Optimization, Impurity Study and Extension to Analogues
title_full Continuous-Flow Synthesis of Nitro-o-xylenes: Process Optimization, Impurity Study and Extension to Analogues
title_fullStr Continuous-Flow Synthesis of Nitro-o-xylenes: Process Optimization, Impurity Study and Extension to Analogues
title_full_unstemmed Continuous-Flow Synthesis of Nitro-o-xylenes: Process Optimization, Impurity Study and Extension to Analogues
title_short Continuous-Flow Synthesis of Nitro-o-xylenes: Process Optimization, Impurity Study and Extension to Analogues
title_sort continuous-flow synthesis of nitro-o-xylenes: process optimization, impurity study and extension to analogues
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9416712/
https://www.ncbi.nlm.nih.gov/pubmed/36014379
http://dx.doi.org/10.3390/molecules27165139
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