N-(4-甲氧基苯基)-N-(2-羧乙基)-β-氨基丙酸的合成

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

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。

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-anisidine 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.