Studies of the degradation mechanism of pyrrolo[3,4-c] pyridine-1,3(2H)-dione derivatives with analgesic activity: isolation and identification of products and summary.

Within the framework of the studies concerning the decomposition of N-substituted derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-dione, the isolation of the alkaline hydrolysis product was performed (pH 10.5, room temperature). Subsequently, based on NMR spectra and two-dimensional spectra, the chemical structure of the isolated compounds was established. The interpretation of COSY, HSQC and HMBC spectra proved that the C1-N2 bond of the pyrrolopyridinedione ring undergoes cleavage under the influence of OH ions and generates a product which is an isonicotinic acid derivative. Owing to the analysis of previous studies, including results presented in this paper, the decomposition mechanism of the compounds studied could be determined.