SYNTHESIS AND PROPERTIES OF N-[2-(BENZOYLAMINO) (2-OXOINDOLIN-3-YLIDENE)ACETYL]AMINO ACIDS ETHYL ESTERS
Analysis of scientifi and patent literature testifi that search of biologically active compounds among derivatives of 2-oxoindoline is prospective. They include well-known amino acids (tryptophane), neurohormone serotonine, a number of natural alkaloids and synthetic drugs (indomethacin, dimecarbin). For many years at the Analytical chemistry department of the National University of Pharmacy the extensive studies have been conducted in the field of development of synthetic methods and the study of physicochemical and biological characteristics of hetarylcarboxylic acids, in particular, 2-oxaindolineacetic acids and products of their transformation in order to search active and harmless medicines. The pharmacological research of (2-oxoindolin-3-ylidene)-2-oxoacetic acid derivatives allow making a conclusion that the highest nootropic activity is shown by substances containing amino acid esters moieties. Extending directions of the target-based search for biologically active compounds and basing on the previous studies it has been decided to include the fragments of amino acids into the core structure - 2-(benzoylamino)(2-oxoindolin-3-ylidene)-2-oxoacetic acid and to carry out the synthesis of N-[2-(benzoylamino)(1-R-2-oxoindolin-3-ylidene)acetyl]amino acids ethyl esters. The structure of the compounds synthesized has been confirmed by the data of elemental analysis, IR- and 1H NMR- spectroscopy. In 1H NMR spectrum of N-[2-(benzoylamino)(1-R-2-oxoindolin-3-ylidene)acetyl]glycine the signal of the methylene group of the amino acid residue is observed as a duplet at δ 4.0 ppm. The signal of the carboxyl group proton in the spectrum of the acid is not observed as a result of deuterium exchange. The signal of СН <sub>2</sub>-group is shifted downfield (4.08 ppm) for the ester. The signals of the ethoxy group are recognized as a quartet at 4.20 ppm (2Н, СН <sub>2</sub>) and a triplet at 1.21 ppm (3Н, СН <sub>3</sub>).