Mospanova O. Synthesis, structure and biological properties of 1-hydroxy-3-oxo-5,6-dihydro-3H-pyrrolo[3,2,1-ij]quinoline-2-carboxylic acid derivatives

As potentially biologically active substances, synthesis of a large group of derivatives of 1-hydroxy-3-oxo-5,6-dihydro-3H-pyrrolo-[3,2,1-i,j]-quinoline-2-carboxylic acid has been performed. In order to improve the effectiveness in obtaining the starting ethyl ester of 1-hydroxy-3-oxo-5,6-dihydro-3H-pyrrolo-[3,2,1-i,j]-quinoline-2-carboxylic acid, it has been proposed to carry out the condensation of indoline with triethylmethane tricarboxylate at a temperature of 215 °С and an equimolar ratio of reagents. By means of derivatography, thermal behaviour of the intermediate products of this reaction has been examined which allowed to avoid the formation of the undesirable methane-tri-N-(indoline-1-yl)-carboxamide during the heterocyclization. Preparative methods of amidation of 1-hydroxy-3-oxo-5,6-dihydro-3H-pyrrolo-[3,2,1-i,j]-quinoline-2-carboxylic acid ethyl ester using alkyl, arylalkyl, aryl and hetaryl amines have been developed. Synthesis of 1-hydroxy-3-oxo-5,6-dihydro-3H-pyrrolo-[3,2,1-i,j]-quinoline-2-carboxylic acid hydrazide was accomplished. This compound was found to be unstable at elevated temperatures which needs to be taken into account in its further chemical transformations. Antituberculous activity, diuretic action and anti-inflammatory activity of the synthesized substances have been studied which made it possible to reveal certain regularity of the structure-activity relationship and to recommend 4-methoxy anilide of 1-hydroxy-3-oxo-5,6-dihydro-3H-pyrrolo-[3,2,1-i,j]-quinoline-2-carboxylic acid for in-depth pharmacological research as a promising diuretic of an essentially new chemical class.