Synthesis of 3-benzylquinoxalin-2(1H)-ones and 4-formyl-3-benzyl-3,4-dihydroquinoxalin-2(1H)-ones from 3-aryloxirane-2-carboxamides via 5-arylidene-2,2-dimethyl-1,3-oxazolidin-4-ones

A facile and highly efficient strategy has been delineated for the synthesis of 3-benzylquinoxalin-2(1H)-ones and their partially reduced N-formyl derivatives via a Hinsberg-Ko euro rner type cyclo-annulation re-action using 5-arylidene-2,2-dimethyl-1,3-oxazolidin-4-ones as pyruvate surrogates. 3-Benzylquinoxalin-2(1H)-ones with a wide range of substituents in both the benzyl moiety and the quinoxaline ring are formed in good to excellent yields and are easily converted into partially reduced N- formyl derivatives when boiled in a mixture of formic acid and formamide (1:1). The method features are mild condition, easy work-up (a simple filtration), practicality and robustness, excellent tolerance to the nature of substituents in starting compounds.(c) 2022 Published by Elsevier Ltd.

Automated summary

A facile and highly efficient strategy has been proposed for the synthesis of 3-benzylquinoxalin-2(1H)-ones and their partially reduced N-formyl derivatives, featuring mild conditions, easy work-up, practicality, and robustness.