Alkylation of quinoxalin-2(1)-ones using phosphonium ylides as alkylating reagents

A practical and efficient methodology for the construction of 3-alkylquinoxalinones through base promoted direct alkylation of quinoxalin-2(1 H )-ones with phosphonium ylides as alkylating reagents under metal- and oxidant-free conditions was developed. Various 3-alkylquinoxalin-2(1 H )-ones were easily obtained in good to excellent yields. Tentative mechanistic studies suggest that this reaction is likely to involve a nucleophilic addition-elimination process. A practical and efficient protocol for the preparation of 3-alkylquinoxalinones through base promoted alkylation of quinoxalin-2(1 H )-ones with phosphonium ylides under metal- and oxidant-free conditions was developed.