Ethanol → 6-hydroxy-4,4-dimethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one

Participants

Reaction Steps

An amount of 237.5 gm (1.146 mol) of 6-methoxy-4,4-dimethyl-4H-3,1-benzoxazin-2-one is dissolved in 2.4 liters of dry ethylene chloride, and 125 ml (330.3 gm=1.3 mol) of boron tribromide are added thereto dropwise, under stirring, at -30° to -40° C. After the addition is complete, the mixture is allowed to return to ambient temperature and left overnight. Then, 1 liter of 50% ethanol is added dropwise, under cooling and stirring, and the mixture is evaporated down to about 500 ml and then diluted with 3 liters of water. The precipitate is subjected to suction filtration and dried.

Provenance & Evidence