Boron tribromide → 5,7-dihydroxy-3-(4-hydroxyphenyl)-4(3H)-quinazolinone

Participants

Reaction Steps

To an ice-cooled mixture of 365 mg (1.17 mmol) of 5,7-dimethoxy-3-(4-methoxyphenyl)-4(3H)-quinazolinone, prepared according to the procedures described in Example 18 or 19, and 10 ml of CH2Cl2, 3 ml of BBr3 (31.7 mmol) was added. The mixture was stirred at room temperature for 2 days. The solvent was evaporated, the obtained residue treated with a cold NaHCO3 solution and extracted with EtOAc. The organic layer was washed with water and brine, dried over MgSO4 and evaporated to yield a solid which purification by flash chromatography on silica gel (loaded with CH2Cl2 and eluted with 66% EtOAc in hexane) gave 165 mg of 5,7-dihydroxy-3-(4-hydroxyphenyl)-4(3H)-quinazolinone (40% yield) as a white solid.

Provenance & Evidence