Abstract
This work describes the investigation of the reactions between o-formylbenzoic acid and morpholine, as well as the alkaloid cytisine. This study is aimed at the synthesis of new aminophthalide derivatives as compounds of potential interest for biological evaluation. The interactions between the starting reagents were studied, and optimal synthesis conditions were determined to ensure high the amounts of desired compounds obtained. The structures, electronic properties of the initial substances, intermediates, and synthesized compounds were analyzed using quantum-chemical computations are based on density functional theory using a quantum‑chemical research method. The molecular constitution of the obtained products were established based on their Infrared spectral data, one-dimensional 1H, 13C and two-dimensional Nuclear Magnetic Resonance spectroscopy (COSY, HMQC, HMBC), and mass spectrometry. A possible reaction pathway accounting for the formation of aminophthalides is presented, involving the nucleophilic addition of secondary amines to the carbonyl group of o-formylbenzoic acid, followed by intramolecular cyclization. The spectral analysis is fully consistent with the proposed structure of the obtained compounds. The findings reveal the effectiveness of the established procedure for synthesizing aminophthalides based on morpholine and cytisine and provide the basis for further studies of their reactivity, physicochemical characteristics, and potential biological activity.