The syntheses of eight 2-alkylamino-4-aminobutyric acids are described. The starting material is 4-butyrolactone, which is opened with potassium phthalimide to give 4-phthalimidobutyric acid. After bromination the 2-bromo-4-phthalimidobutyric acid, obtained in excellent yield, is treated with aliphatic amines in alcoholic medium to give the desired substituted 2,4-diaminobutyric acids, which were characterized as the monohydrochlorides and the di(phenylcarbamates). Three of them cyclized easily to give the corresponding hydantoins. In the course of the reaction, substituted diamides of phthalic acid were isolated and characterized.
本文介绍了合成八种2-烷基氨基-4-氨基丁酸的方法。起始材料为4-丁酰内酯,它与邻苯二甲酰亚胺钾开环,形成4-邻苯二甲酰亚胺丁酸。溴化后,得到优良产率的2-溴-4-邻苯二甲酰亚胺丁酸,然后在醇介质中与脂肪胺反应,制得所需的取代2,4-二氨基丁酸,其作为单一盐酸盐和二苯基氨基甲酸酯被表征。其中三种很容易环化成相应的咪唑二酮。在反应过程中,分离并表征了邻苯二甲酸的取代二酰胺。