微波辐射合成荧光增白剂PEB

利用微波技术,采用正交实验方法,以2-羟基-1-萘甲醛和丙二酸二乙酯为原料,乙酸酐为催化剂,合成了5,6-苯并香豆素-3-甲酸乙酯(荧光增白剂PEB)。考察了四个因素(微波作用时间,微波辐射功率,原料投料比,催化剂用量)等因素对产物产率的影响。实验证明:以微波功率195W,2-羟基-1-萘甲醛(A)、丙二酸二乙酯(B)、催化剂(C)的投料摩尔比为1.5∶1∶2,加热时间30 min,产物收率可达89%。较之传统加热方法(反应时间6 h,收率80%)反应时间大大缩短,反应收率也有所提高。

Synthesis of Fluorescent Whitening Agent PEB via Microwave Irradiation

5,6-Benzocoumarin-3-ethyl formate(fluorescent whitening agent PEB)was synthesized with 2-hydoxyl-1-naphtha-aldehyde and diethyl malonate as starting materials and acetic anhydride as catalyst under microwave irradiation.The orthogonal design experiment was used to optimize the reaction conditions(time,power of microwave radiation,molar ratio of reagents and catalyst amount).The experimental results showed that when the microwave radiation power was 1 95 W,the molar ratio of 2-hydoxyl-l-naphthaldehyde(A):diethyl malonate(B):catalyst(C)was 1.5:1:2 and the reaction time was 30 minutes,the yield of PEB was 89%.Comparing with the original method(yield 80 0A,reaction time 6 h),the synthesis method can shorten the reaction time and increase the yield.