1,3-二甲基-2-咪唑啉酮的制备

以乙二胺、尿素、甲醛和甲酸为原料,经过环化和甲基化反应制得目标产物1,3-二甲基-2-咪唑啉酮(1,3-DMI)。通过红外、核磁对其结构进行了确证。考察了溶剂、原料浓度、原料摩尔比、反应温度和时间、催化剂对制备(1,3-DMI)收率的影响。较佳工艺条件为:制备2-咪唑啉酮时,以水-乙二醇混合作溶剂;制备1,3-DMI时,甲醛(36%)∶甲酸(85%)摩尔比为1∶2.8,反应温度95~100℃,反应时间16 h,氯化亚铜和三乙胺作催化剂,用量分别是2-咪唑啉酮摩尔数的1.0%。总收率达到71%,纯度为98.5%。

Preparation of 1,3-dimethyl-2-imidazolidinone

Using ethylenediamine,urea,methanal and formic acid as base material,1,3-dimethyl-2-imidazolidinone was prepared via cyclization reaction and methylation.Its structure was characterized by IR and 1H NMR.The effect of solvent,material concentration,material ratio,reaction temperature and reaction time,catalyst on the preparation were studied.The better technology has been obtained:taking water-EG as solvent 2-imidazolidinone was prepared.The molar ratio of the methanal(36%) to the formic acid(85%) is 1 ∶2.8,reaction temperature is 95～100 ℃,reaction time is 16 h,taking cuprous chloride and triethylamine as catalyst,the molar ratio of the cuprous chloride and triethylamin to 2-imidazolidinone is 1.0% while 1,3-DMI was prepared.The yield of 1,3-DMI could reach 71%,the purity of 1,3-DMI is 98.5%.