Features of –C–C– Coupling of Quinoxaline-2-one with Ethyl Acetoacetate under Acid Catalysis

Received: 16.11.2021. Revised: 11.01.2022. Accepted: 11.01.2022. Available online: 14.01.2022.The replacement of hydrogen led to the formation of water, which activated the process of cleavage of the dicarbonyl group of 3-(2-oxopropylideno)-3,4-dihydroquinoxaline-2-one. The acyl group of com pound 3-(2-oxopropylideno)-3,4-dihydroquinoxaline-2-one was "vicarious" in this reaction.The formation of 3-(3-oxo-3,4-dihydroquinoxaline-2-(1H)-ylidene) methylquinoxaline-2-(1H)-one was the result of C,C-coupling of compounds quinoxaline-2-one and 3-(2-oxopropylideno)-3,4-dihydroquinoxaline-2-one, similarly to the reaction of quinoxaline-2-one 1 with acetone.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.Quinoxalin-2-one (1) reacts with ethyl acetoacetate in trifluoroacetic acid (TFA) to form 3-(2-oxopropylideno)-3,4-dihydroquinoxaline-2-one (2) and 3-(3-oxo-3,4- dihydroquinoxaline-2-(1H)-ylidene)methylquinoxaline-2-(1H)-one (3). The reaction product 3 was also obtained by heating the compound 1 with acetone in the presence of TFA