Triethylamine → 4-Bromo-2-phenylquinazoline

Participants

Reaction Steps

Into a mixture of 5 g of 2-phenylquinazolin-4(3H)-one and 1.82 g of triethylamine in 100 ml of toluene was added a solution of 25.8 g of phosphorus oxybromide in 50 ml of toluene. The mixture was warmed slightly and the insoluble quinazolinone dissolved slowly, with a new solid appearing. The reaction mixture was heated at 80°-85° for approximately 24 hours. The reaction mixture was cooled and the solid which separated was collected on a filter. The collected solid was dissolved in chloroform, was washed twice with 100-ml portions of water and the washed solution dried over magnesium sulfate. The solution was concentrated to dryness to leave a light orange solid, m.p. 131°-132°. This solid was recrystallized from cyclohexane to give 2.97 g of light yellow 4-bromo-2-phenylquinazoline, m.p. 131.5°-132.5°; ir and nmr spectra were consistent with the assigned structure.

Provenance & Evidence