Synthesis of 3,4-Dialkoxypyrroles via Paal-Knorr Cyclization under Mild Conditions
In this work, an efficient and environmentally friendly method for the synthesis of new 3,4-diethoxypyrrole derivatives has been developed using molecular iodine as a catalyst. 2,3,4,5-Tetraethoxytetrahydrofuran was employed as the starting substrate, which reacts with primary amines in the presence of 10 mol% I2. It was shown that the use of molecular iodine allows the reaction to proceed under mild conditions, significantly reduces the reaction time and affords the target compounds in good yields. The developed methodology is characterized by operational simplicity and good efficiency. The synthesized compounds may serve as useful intermediates for further transformations, while their potential applications require additional investigation.