Phenacyl bromide → 7-methyl-3-phenyl-2H-1,4-benzoxazine

Participants

Reaction Steps

To potassium carbonate (63.89 g, 462 mmol) in water (300 mL) and CH2Cl2 (200 mL) is added 6-amino-m-cresol (10.0 g, 81.2 mmol) and tetra-n-butyl ammonium hydrogensulfate (0.139 g, 0.41 mmol). With vigorous stirring a solution of 2-bromoacetophenone (16.16 g, 81.2 mmol) is added dropwise over a period of 45 min. The mixture is allowed to stir overnight. The layers are then separated and the organic layer is washed with 1N NaOH (500 mL) and water (2×300 mL), dried over magnesium sulfate and concentrated. Column chromatography (400 g silica gel) using ethyl acetate/hexane (20/80) as eluent gave 8.96 g (49%) of 7-methyl-3-phenyl-2H-1,4-benzoxazine.

Provenance & Evidence