N-(4-甲氧基苯基)-N-(2-羧乙基)-β-氨基丙酸的合成

以4-硝基苯甲醚为原料经催化加氢制备了中间产物4-甲氧基苯胺,再与丙烯酸反应合成了N-(4-甲氧基苯基)-N-(2-羧乙基)-β-氨基丙酸(Ⅰ)。考察了两步反应中反应温度、反应时间、溶剂种类、催化剂用量和溶剂用量对收率的影响。结果表明:第1步反应中,以5 g 4-硝基苯甲醚为底物,10 mL乙醇为溶剂,反应温度50℃,氢气压力0.6～0.8 MPa,催化剂用量0.8 g(湿重),4-甲氧基苯胺的收率达到91.5%;第2步反应中,n (4-甲氧基苯胺):n(丙烯酸)=1:4,乙酸乙酯为溶剂,反应温度45℃,反应时间10 h,产物Ⅰ的收率达到83.8%。通过质谱、核磁和红外对目标产物的结构进行了表征。

SYNTHESIS OF N-(4-METHOXYPHENYL)-N-(2-CARBOXYLETHYL)-β-ALANINE

4-anisidine was prepared by catalytic hydrogenation of 4-nitroanisole.N-(4-methoxyphenyl)- N-(2-carboxylethyl)-β-alanine was further synthesized with 4-anisidine and acrylic acid.Reaction con- ditions such as reaction temperature,reaction time,solvent,amount of catalyst,solvent volume, etc.,were studied.The optimum conditions for the two reactions were found as follows,synthesis of 4-anisidine:4-nitroanisole 5 g,10 mL ethanol as solvent,50℃,hydrogen pressure 0.6-0.8 MPa, 0.8 g catalyst(wet),with the yield of 4-anisidine being up to 91.5%(literature yield 82%);synthesis of N-(4-methoxyphenyl)-N-(2-carboxylethyl)-β-alanine.10 mL ethyl acetate,molar ratio of 4-anisi- dine to acrylic acid 1:4,45℃for 10 h,with the yield of the product being about 83.8%(literature yield 47.2%).Structure of the title compound was confirmed by NMR,IR and MS spectra.