1,3-二溴-5,5-二甲基海因的绿色合成

Green Synthesis of 1,3-Dibromo-5,5-Dimethylhydantoin

以溴酸钾、氢溴酸、硫酸、5,5-二甲基海因(DMH)为原料,讨论了1,3-二溴-5,5-二甲基海因(DBDMH)的绿色合成。考察了溴酸钾与氢溴酸的比例、DMH的用量、硫酸的用量、水的用量和析出温度对1,3-二溴-5,5-二甲基海因收率的影响。结果表明在原料配比n(溴酸钾)∶n(氢溴酸)∶n(硫酸)∶n(DMH)=1∶2∶0.6∶1.3,水30mL,反应温度为25℃,反应时间为1h,析出温度为冰水浴时,产品收率达92%。

1, 3-dibromo-5,5-dimethylhydantoin is synthetised by the reaction of potassium bromide,hydrobromic acid, sulfuric acid and 5,5-dimethylhydantoin. The influences of the molar ratio of potassium bromide to hydrobromic acid, 5, 5-dimethylhydantoin and sulfuric acid amounts, water volume, and crystallizing point on the bromination are studied. The results indicate the optimized reaction conditions∶n（KBrO3）∶n（HBr）∶n（H2SO4）∶n（DMH）=1∶2∶0.6∶1.3, water 30 ml, reaction temperature 25℃, reaction time 1 h, crystallizing point 0 ℃. Under these conditions, 1, 3-dibromo-5,5-dimethylhydantoin is obtained with 92% yield.