2-Amino-4-Bromophenol → 5-Bromo-1,3-benzoxazole-2-thiol

Participants

Reaction Steps

Potassium ethyl xanthate (416 mg, 2.60 mmol) was added to a solution of 2-amino-4-bromophenol (244 mg, 1.30 mmol) in EtOH (3.24 mL). The reaction mixture was heated at reflux for 4 h. Upon cooling to RT the mixture was concentrated and the resulting residue was dissolved in water. Acetic acid was added until pH=5 and a white solid precipitated from the solution. The solid was filtered, washed with water and dried to afford 270 mg (90%) of a tan powder which was used without further purification: 1H NMR (d6-DMSO, 400 MHz) δ 14.02 (s, 1H), 7.47-7.38 (m, 3H); 13C (d6-DMSO, 400 MHz) δ 181.4, 148.1, 133.7, 127.1, 117.8,118.8, 112.2; MS (Cl) m/z 229.8 (M−1); HPLC retention time=4.34 min.

Provenance & Evidence