1,1'-Carbonyldiimidazole → Brofoxine

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-(2-amino-5-bromophenyl)propan-2-ol (18 g, 78 mmol) in dry THF (150 mL) was added 1,1′-carbonyldiimidazole (15.5 g, 94 mmol) under nitrogen. The reaction solution was heated at 50° C. overnight. The solvent was removed in vacuo and the residue was dissolved in ethyl acetate (100 mL). The solution was washed with 1N aqueous hydrochloride solution (2×40 mL), brine (20 mL), and dried with MgSO4. After removal of solvent in vacuo, 6-bromo-4,4-dimethyl-1,4-dihydro-benzo[d][1,3]oxazin-2-one was obtained as a white solid (20 g, 100%): mp 199-200° C.; 1H-NMR (DMSO-d6) δ 10.32 (s, 1H, D2O exchangeable), 7.48 (d, 1H, J=2.1 Hz), 7.43 (dd, 1H, J=8.5, 2.1 Hz), 6.84 (d, 1H, J=8.4 Hz), 1.61 (s, 6H).

Provenance & Evidence