| 摘要 |
1,156,389. Ester and amide derivatives of pyroglutamic acid. LABORATOIRES D'ELECTRONIQUE ET D'AUTOMATIQUE DU NORD "LEANORD." 14 March, 1967 [15 March, 1966], No. 11918/67. Heading C2C. [Also in Division C5] Novel compounds of the formula where R 1 is H, alkyl, alkenyl, aralkyl, alkoxy, aralkoxy or alkylamino, which radicals may optionally be substituted and R 2 is amino, alkoxy with at least 5 carbon atoms, aryloxy, cycloalkoxy or heteroalkoxy, which radicals may optionally be substituted, as well as known compounds of Formula (I) in which R 2 is C 1-4 alkoxy, are made by heating glutamic acid at 160-180‹ C. until practically all the water is removed, allowing it to cool to 120‹ C., adding the alcohol to be esterified, removing the water of reaction by azeotropic distillation with benzene, toluene or xylene and isolating the pure pyroglutamate ester by distillation under reduced pressure. Alkylation of the ester substitutes R 1 alkyl for R 1 hydrogen. The esters may also be prepared by transesterification. The amides are made by heating pyroglutamic acid or its alkyl ester with the appropriate amine. |
