1,2-Dibromoethane → 10-Bromo-5,6-dihydroimidazo[1,2-d][1,4]benzoxazepine

Participants

Reaction Conditions

Reaction Steps

Into a 20 L 4-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen was placed a solution of 4-bromo-2-(1H-imidazol-2-yl)phenol (835 g, 3.49 mol, 1.00 equiv) in N,N-dimethylformamide (8.5 L), 1,2-dibromoethane (2366 g, 12.59 mol, 3.60 equiv), potassium carbonate (1930 g, 4.00 equiv), and Cs2CO3 (1160 g, 1.00 equiv). The resulting solution was stirred at 100° C. overnight, quenched by the addition of 20 L of water/ice and extracted with 4×10 L of ethyl acetate. The combined organic layers were washed with 4×5 L of brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The crude product was re-crystallized from EA:PE (1:2) to afford 350 g (38%) of 9-Bromo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene.

Provenance & Evidence