Acetic Anhydride → 1-Acetamido-1,4-dihydro-2,3-quinoxalinedione

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-amino-1,4-dihydro-2,3-quinoxalinedione (53 mg, 0.30 mMol) and pyridine (1 mL, fresh distilled from KOH before use) and acetic anhydride (1 mL, Aldrich) was stirred under nitrogen at 60° C. for 4 hrs. The reaction mixture became a clear solution. All of solvent and reagent were then evaporated under reduced pressure and washed with benzene:cyclohexane=1:1(2×2 mL); ether (2×2 mL), dried at 60° C. with rotavapor for 2 h, affording 57 mg (86%) of pure 1-acetamido-1,4-dihydro-2,3-quinoxalinedione as a white powder; mp:211°-213° C. IR (KBr, cm-1): 3430; 3127; 1741; 1717; 1668. NMR (1H, DMSO-d6) δ:2.326 (s, 3H); 7.121-7.287 (m, 4H); 12.345 (s, 1H). Mass:calcd for C10H9N3O3 (M+) m/z:219.0641; found: 219.0651.

Provenance & Evidence