N-(1,1-二甲基-3-氧代丁基)丙烯酰胺的合成

Synthesis of N-(1,1-dimethyl-3-oxobutyl)acrylamide

对以丙酮和丙烯腈为原料,浓硫酸催化合成N (1,1 二甲基 3 氧代丁基)丙烯酰胺(DAAm)的工艺进行了改进,通过结晶获取中间产物并对其进行洗涤的方法,可提高产品纯度,简化工艺操作。确定的最佳工艺条件为:n(丙烯腈)∶n(丙酮)∶n(浓硫酸)=1∶2 3∶2 3;反应时间4h;反应温度50℃;结晶稀释剂(相对1mol丙烯腈)240mL。得到DAAm白色晶体,纯度:w(DAAm)=99 8%,熔点:56 3～56 8℃,相对丙烯腈的收率为50 6%。用熔点、IR、1HNMR确认产物。

The technology for synthesis of N(1,1dimethyl3oxobutyl)acrylamide (DAAm) from acetone and acrylonitrile with conc.H2SO4 as catalyst was improved. Adopting the method of separating the intermediate by crystallization followed by washing,purity of the product was increased and the technological operation became simpler.The optimized reaction conditions were determined as follows:n(acrylonitrile)∶n(acetone)∶n(98% H2SO4)=1∶23∶23,reaction time 4 h,reaction temperature 50 ℃,and the amount of acetone for diluting(based on 1 mol acrylonitrile) 240 mL.White DAAm crystals were obtained with the purity w(DAAm)=998% and m.p.563-568 ℃.Yield of DAAm was 506% based on acrylonitrile.The target product was identified by m.p.,IR and 1HNMR.