离子液体一步法催化合成4-乙酰胺基苯亚磺酸

Catalytic Synthesis of 4-Acetamidobenzenesulfinic Acid by Ionic Liquids in One Step

离子液体作为一类同时具备优良溶剂性能与催化活性的新兴绿色催化剂,在各类反应当中有着广泛的应用。开发了以乙酰苯胺和SO2为原料,采用离子液体一步法催化原料亚磺化反应合成4-乙酰胺基苯亚磺酸的新工艺,其中离子液体在反应过程中同时作为溶剂与催化剂。考察了多种离子液体一步法合成4-乙酰胺基苯亚磺酸,确定三乙胺盐酸盐/AlCl3为最适宜离子液体,并进一步考察了三乙胺盐酸盐/AlCl3自身物质的量配比、反应温度和反应时间等条件对其催化性能的影响;同时探讨了离子液体在反应中真正起催化作用的活性组分是[Al2 Cl7]-。离子液体一步法催化合成4-乙酰胺基苯亚磺酸最适宜反应条件为:反应温度为90℃、反应时间为4 h、n(三乙胺盐酸盐)∶n(AlCl3)=0.55∶1.00(记为0.55Et3 NHCl/AlCl3)。在最适宜反应条件下,液相收率达到89.55%。通过IR、LC-MS和1 H NMR等分析对产物结构进行了鉴定。

Ionic liquids,as a new kind of green catalysts with excellent solvent performance and catalytic activity,have been widely used in various reactions.A new one-step synthesis process of 4-acetamidobenzenesulfinic acid using acetanilide and SO2 has been developed in this article.Ionic liquid acts as both solvents and catalysts in the reaction.The one-step synthesis of 4-acetamidobenzenesulfinic acid from various ionic liquids are investigated.Triethylamine hydrochloride/AlCl3 is selected as the optimum ionic liquid.The effects of the molar ratio of triethylamine hydrochloride/AlCl3,reaction temperature and reaction time on its catalytic performance are further investigated.The real active component of ionic liquids in the reaction is[Al2 Cl7]-.The optimum reaction conditions for the synthesis of 4-acetamidobenzenesulfinic acid catalyzed by ionic liquids in one step are as follows:reaction temperature 90℃,reaction time 4 h,triethylamine hydrochloride/AlCl3 molar ratio 0.55∶1.00(denoted as 0.55Et3 NHCl/AlCl3).Under the optimum reaction conditions,the liquid yield reached 89.55%.The target product is analyzed by IR,LC-MS and 1 H NMR.