Facile and clean electrochemical synthesis of new acetaminophen derivatives through electrochemical oxidation of acetaminophen in the presence of thiouracil derivatives

摘要

The electrochemical oxidation of acetaminophen (1a) is carried out in the presence of thiouracil derivatives (3a-c), as nucleophiles, in an acetate buffer solution (0.15M, pH 5) mixed with Dimethylformamide (DMF) using cyclic voltammetry and coulometry under a constant potential. The results obtained indicate that N-acetyl-p-benzoquinone-imine derived from acetaminophen participates in a 1,4-Michael-type addition reaction with thiouracils to form the corresponding acetaminophen derivatives (4a-c) in good yields and with high purities using a facile, catalyst-free, and one-pot electrochemical method using three carbon electrodes in an undivided cell under mild conditions. The products obtained were characterized after purification by IR, H-1 NMR, and C-13 NMR spectroscopies, and by the elemental analysis method.