1,1-二钾硫基二硝基乙烯的合成

Synthesis of dipotassium salt of 1-nitro-2,2-bismercaptoethylene

1,1-二钾硫基二硝基乙烯是合成雷尼替丁中间体N-甲基-1-甲硫基-2-硝基乙烯胺的中间产品。通过主、副反应的对比选择性方程分析反应温度和反应物浓度对产品收率的影响,采取3项措施提高反应的选择性:1)使反应温度由目前的25℃提高到40℃;2)将一次性加入二硫化碳改为滴加;3)将氢氧化钾乙醇溶液的体积分数由30%降为20%。改进后的新工艺产品收率达到90%,具有很好的工业前景。研究表明,通过主、副反应对比选择性方程的温度效应和浓度效应分析,调整工艺条件和加料方法,达到了提高产品收率的目的。

Dipotassium salt of 1-nitro-2,2-bismercaptoethylene is the key intermediate which can be used to produce N-methyl-1-methylthio-2-nitroethenamine.The selectivity equations of main and side reactions were developed to analyze the effect of temperature and concentration,and for reducing side-product and enhancing product yield the following improving measures are taken: 1) increasing the temperature from 25 ℃ to 40 ℃;2)adding CS2 slowly and dropwisely;3)diluting the concentration of KOH/C2H5OH from 30% to 20%.With adopting new synthesis technology,the product yield increases to over 90%.The new synthesis technology is of potential for industrial-scale production.Current results indicate that,via analyzing the effect of temperature and concentration,then taking correspondent means to adjust and modify the reaction conditions and the feeding fashions,the aim of increasing product yield can be achieved.