Carbon Dioxide → 10-Bromo-5,6-dihydrobenzo[F]imidazo[1,2-D][1,4]oxazepine-2-carboxylic acid

HRID 575014Notes

Reaction equation

[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:14][CH2:13][CH2:12][N:11]3[C:7](=[N:8][C:9](I)=[CH:10]3)[C:6]=2[CH:16]=1.CC[Mg+].[Br-].[C:21](=[O:23])=[O:22].Cl>O1CCCC1>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:14][CH2:13][CH2:12][N:11]3[C:7](=[N:8][C:9]([C:21]([OH:23])=[O:22])=[CH:10]3)[C:6]=2[CH:16]=1

Participants

Conditions

Temperature: -30 °C

Procedure

Into a 20 L 4-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen was placed a solution of 9-Bromo-2-iodo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene (700 g, 1.79 mol, 1.00 equiv) in tetrahydrofuran (13 L), followed by the addition of EtMgBr (1400 mL) dropwise with stirring at −30° C. over 60 min. To the above an excess of CO2 (gas) was introduced in over 3 h at −78° C. The resulting solution was warmed to room temperature naturally. The pH value of the solution was adjusted to 3 with hydrogen chloride (2 mol/L). The precipitates were collected by filtration, washed with 2×100 mL of EA and dried in a vacuum oven to afford 410 g (74%) of 9-Bromo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene-2-carboxylic acid as a white solid.

Workup

customInto a 20 L 4-necked round-bottom flask purged
temperaturemaintained with an inert atmosphere of nitrogen
temperatureThe resulting solution was warmed to room temperature naturally
filtrationThe precipitates were collected by filtration
washwashed with 2×100 mL of EA
customdried in a vacuum oven

Sources & evidence

ORD record: ord-6455b263a54e4d56a1a539a79fc68537
Source dataset: uspto-grants-2015_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09034866B2

Reaction notes

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