Sulfuric Acid → 3,7-Dibromodibenzo[b,d]furan

Participants

Reaction Conditions

Reaction Steps

A solution of sodium nitrite (4.17 g, 60.5 mmol) in water (55.7 mL) was added slowly to a suspension of 2-methoxy-2′-amino-4,4′-dibromobiphenyl (16, 21.60 g, 60.50 mmol) in H2SO4 (14.82 g, 151.3 mmol) in water (52.7 mL), maintained below 2° C. The mixture was stirred for 2 h at 0° C., and then excess urea was added to destroy the unreacted nitrous acid. The reaction mixture was stirred overnight at room temperature, then overnight at 70° C. The solid formed was collected and recrystallized from benzene (120 mL) and methanol (100 mL) to give a beige solid (10.27 g, 52.09%): mp 199-200.5° C.; HPLC method 3 tR=20.99 min (100 area %); 1H NMR (300 MHz, CDCl3) δ 7.78 (d, J=8.2 Hz, 2 H), 7.74 (d, J=1.2 Hz, 2 H), 7.49 (dd, J1=8.2 Hz, J2=1.2 Hz, 2 H); EI-Ms m/z 324 (M+). Anal. (C12H6OBr2) C, H, N.

Provenance & Evidence