Hydrochloric Acid → 6-Acetyl-2-ethoxycarbonyl-4-methyl-3,4-dihydro-2H-1,4-benzoxazine

Participants

Reaction Steps

1.6 mmol (0.1 ml) of acetyl chloride and 4 mmol (545 mg) of aluminum chloride are added to a solution of 1.6 mmol (355 mg) of 2-ethoxycarbonyl-4-methyl-3,4-dihydro-2H-1,4-benzoxazine (described in J. Heterocyclic Chem., 1985, 22, 177) in 18 ml of dichloromethane at -10° C. The reaction mixture is stirred at room temperature for 1 hour before being hydrolysed by a cooled aqueous solution of 2 M hydrochloric acid. The mixture is extracted with dichloromethane and the organic phase is washed with a saturated solution of NaHCO3, dried over magnesium sulphate, concentrated and purified by chromatography on silica gel using a petroleum ether/ethyl acetate mixture (7/3) as eluant to yield the expected product.

Provenance & Evidence