Aspartyl phenyl alanine esters as sweet - ening agents

摘要

The esters (I) are prepared by condensation of a protected L-aspartly anhydride (II) with L-phenylalanine ester (III), followed by removal of the protecting group by conventional means. where R = lower alkyl R1 = formyl, carbobenzoxy, or p-methoxy carbobenzoxy. E.g. 9 g (III) HCl, R = CH3 was neutralised then treated with 5g (II) R = carbobenzoxy in ethyl acetate at room temperature. After eliminating the isomeric beta-amide the protecting group was removed by hydrogenation to give 4g (I) mpt. 234-235 degrees C.