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Herein, the development of a visible‐light‐induced catalytic system to achieve the decarboxylative acylation of pyridine N‐oxides with α‐oxocarboxylic acids, at room temperature and using the organic dye fluorescein dimethylammonium as a new type of photocatalyst, is reported. A series of 2‐arylacylpyridine N‐oxides were selectively synthesized in moderate to good yields by controlling the polarity of the reaction solvent. The developed strategy was successfully applied in the synthesis of an important intermediate of the drug, acrivastine, on a gram scale. Notably, this is the first time that fluorescein dimethylammonium has been used to catalyze the Minisci‐type C−H decarboxylative acylation reaction. The mechanism of decarboxylative acylation was studied by capturing adducts of acyl radicals and 1,1‐diphenylethylene to confirm a radical mechanism. The disclosed catalytic system provides a green synthetic strategy for decarboxylative acylation without the use of additional oxidants or metal catalysts.

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An effective method for the synthesis of benzazoles through the electrochemical oxidative cyclization of o-aminophenol/oaminothiophenol/o-phenylenediamine and aldehydes was developed. A series of benzazoles were efficiently synthesized by using this method in good yields. Furthermore, this method was applied to the synthesis of the drug thiabendazole in a gram-scale reaction, which proved the practicality of the method. This approach avoids using catalysts and oxidants, and has the advantages of wide substrate range, mild reaction conditions and good tolerance of functional groups. Finally, the possible reaction mechanism was proposed and supported by cyclic voltammetry (CV) and control experiments.