Methanol → Methyl 9-bromo-5,6-dihydrobenzo[f]imidazo[1,2-d][1,4]oxazepine-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

8-Bromo-2-iodo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene (6.000 g, 0.01534 mol) followed by palladium acetate (0.1722 g, 0.0007672 mol) and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.8879 g, 0.001534 mol) were added sequentially to a dry nitrogen-filled flask. Degassed triethylamine (180 mL, 1.3 mol) and methanol (60 mL) were added, and the reaction mixture was thoroughly purged with a carbon monoxide balloon for about 3 minutes. Two carbon monoxide balloons were fixed to the flask and the reaction was heated to 50° C. for 3 hours. The reaction was purged with nitrogen, concentrated in vacuo, and dry loaded onto silica gel. The crude was purified by flash chromatography (40-100% ethyl acetate in hexanes followed by 5-15% MeOH in DCM) to give 8-Bromo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene-2-carboxylic acid methyl ester (4.242 g) as a light brown solid. MS (ESI+) 323.0/325.0

Provenance & Evidence