Dimethylformamide → 9-Bromo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene-2-carbonyl chloride

Participants

Reaction Conditions

Reaction Steps

Into a 10000-mL 4-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen was placed a solution of 9-Bromo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene-2-carboxylic acid (450 g, 1.46 mol, 1.00 equiv) in ACN (4500 mL), followed by the addition of (COCl)2 (450 mL) dropwise with stirring at 0° C. over 45 min. To this was added N,N-dimethylformamide (5 mL). The resulting solution was stirred at room temperature for 7 h, diluted with 2000 mL of DCM and concentrated under vacuum to afford 450 g (94%) of 9-Bromo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene-2-carbonyl chloride as a gray solid.

Provenance & Evidence