Imidazole → (S)-3-methyl-3-(2-methyl-5-nitro-4-oxoquinazolin-3(4H)-yl)piperidine-2,6-dione

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-methyl-5-nitro-4H-benzo[d][1,3]oxazin-4-one (2.0 g, 9.7 mmol), (S)-3-amino-3-methylpiperidine-2,6-dione hydrobromide (2.2 g, 9.7 mmol), imidazole (1.5 g, 21 mmol), and triphenylphosphite (3.7 g, 12 mmol) in DMF (20 mL) was stirred under nitrogen at 45° C. for 40 hours. The mixture was evaporated, and the residue was chromatographed on silica gel using a dichloromethane-acetonitrile gradient. The product eluted at 15% acetonitrile, providing (S)-3-methyl-3-(2-methyl-5-nitro-4-oxoquinazolin-3(4H)-yl)piperidine-2,6-dione as a yellow solid (0.70 g, 22% yield); 1H NMR (DMSO-d6) δ 1.94 (s, 3H, CH3), 2.35-2.40 (m, 1H, CHH), 2.45-2.59 (m, 2H, 2CHH), 2.71-2.83 (m, 4H, CH3, CHH), 7.75-7.82 (m, 2H, Ar), 7.95 (dd, J=8, 8 Hz, 1H, Ar), 10.86 (s, 1H, NH).

Provenance & Evidence