Pt-C催化剂催化邻氯硝基苯加氢制备2,2′-二氯氢化偶氮苯

2015年7月第23卷第7期 工业催化INDUSTRIAL CATALYSIS July 2015Vol.23 No.7精细化工与催化收稿日期:2015-02-04

作者简介:杨乔森,1978年生,男,陕西省乾县人,高级工程师。Pt /C 催化剂催化邻氯硝基苯加氢制备2,2?-二氯氢化偶氮苯

杨乔森

(西北有色金属研究院,陕西西安710016)

摘 要:以邻氯硝基苯为原料,在碱性环境中以Pt /C 为催化剂,进行加氢还原生成2,2?-二氯氢化偶氮苯。考察溶剂、反应压力、反应温度及氢氧化钠浓度等对加氢反应的影响,确定了最佳的工艺

条件,在氢氧化钠浓度20%、

甲苯/氢氧化钠溶液作溶剂、反应温度80?和反应压力0.8MPa 条件下,2,2?-二氯氢化偶氮苯收率超过88%。与传统硫化碱还原或铁粉还原工艺相比,催化加氢法在减少废水和降低成本等方面优势较大。

关键词:精细化学工程;Pt /C 催化剂;催化加氢;邻氯硝基苯;2,2?-二氯氢化偶氮苯

doi :10.3969/j.issn.1008-1143.2015.07.017

中图分类号:TQ246.1+3;O643.36 文献标识码:A 文章编号:1008-1143(2015)07-0570-03

Preparation of 2,2?-dichlorohydrazobenzene through catalytic hydrogenation of o -chloronitrobenzene over Pt /C catalyst

Yang Qiaosen

(Northwest Institute for Non-ferrus Metal Research ,Xi ’an 710016,Shaanxi ,China )

Abstract :Using o -nitrochlorobenzene as the raw material ,2,2?-dichlorohydrazobenzene was prepared in the alkaline medium over Pt /C catalyst.The effects of the solvents ,reaction pressure ,reaction tempera-tures and sodium hydroxide concentration on the hydrogenation reaction was investigated.The optimum reaction condition was determined.The results showed that 2,

2?-dichlorohydrazobenzene yield of more than 88%was obtained under the condition as follows :reaction temperature 80?,reaction pressure 0.8MPa ,sodium hydroxide mass fraction 20%,and toluene-sodium hydroxide mixture solution as the https://www.360docs.net/doc/fe2986039.html,-pared with conventional processes of sulfide reduction and reduction of iron powder ,

the catalytic hydrogenation had more advantages with respect to reducing waste water and production cost.Key words :fine chemical engineering ;Pt /C catalyst ;catalytic hydrogenation ;o -nitrochlorobenzene ;2,2?-dichlorohydrazobenzene doi :10.3969/j.issn.1008-1143.2015.07.017CLC number :TQ246.1+3;O643.36 Document code :A Article ID :1008-1143(2015)07-0570-03

2,2?-二氯氢化偶氮苯是一种重要的有机颜料

中间体3,

3?-二氯联苯胺盐酸盐的中间产物,3,3?-二氯联苯胺盐酸盐生产的黄色有机颜料占总黄色类颜料的25%,也可用于染料和医药中间体的合成。目前合成2,2?-二氯氢化偶氮苯的方法主要有化学还原法、电解还原法和催化加氢法等,催化

加氢法最通用[1-4],副产物少,经济环保,主要原料是邻硝基氯苯,在碱性条件及相应有机溶剂中与铂

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