Hydrochloric Acid → 9-(dibenzo[b,d]thiophen-4-yl)-9H-carbazol-3-ylboronic acid

HRID 1753712Notes

Reaction equation

[Li]CCCC.CCCCCC.Br[C:13]1[CH:14]=[CH:15][C:16]2[N:17]([C:26]3[C:31]4[S:32][C:33]5[CH:38]=[CH:37][CH:36]=[CH:35][C:34]=5[C:30]=4[CH:29]=[CH:28][CH:27]=3)[C:18]3[C:23]([C:24]=2[CH:25]=1)=[CH:22][CH:21]=[CH:20][CH:19]=3.C[O:40][B:41](OC)[O:42]C.Cl>O1CCCC1>[CH:29]1[C:30]2[C:34]3[CH:35]=[CH:36][CH:37]=[CH:38][C:33]=3[S:32][C:31]=2[C:26]([N:17]2[C:16]3[CH:15]=[CH:14][C:13]([B:41]([OH:42])[OH:40])=[CH:25][C:24]=3[C:23]3[C:18]2=[CH:19][CH:20]=[CH:21][CH:22]=3)=[CH:27][CH:28]=1

Participants

Conditions

Temperature: 0 °C

Procedure

An excess of 1.6M n-BuLi in hexane (14 mL, 22.3 mmol) was added to a solution of 3-bromo-9-(diberizo[b,d]thiophen-4-yl)-9H-carbazole (8.7 g, 20.3 mmol) in 100 ml dry tetrahydrofuran at −78° C. under N2. The reaction mixture was then maintained at 0° C. for 1 h before cooling to −78° C. Trimethylborate (2.8 g, 26.4 mmol) was added dropwise; the solution was then warmed slowly to room temperature and stirred for 24 h. 2N HCl (50 ml) was added and then the mixture was stirred for a further 1 h. The reaction mixture was extracted with ethyl acetate and water, dried with anhydrous magnesium sulfate, the solvent was evaporated in vacuum, and the residue was crystallized from n-hexane to give the 9-(dibenzo[b,d]thiophen-4-yl)-9H-carbazol-3-ylboronic acid 4.7 g (59%)

Workup

temperaturebefore cooling to −78° C
temperaturethe solution was then warmed slowly to room temperature
stirringthe mixture was stirred for a further 1 h
extractionThe reaction mixture was extracted with ethyl acetate and water
dry with materialdried with anhydrous magnesium sulfate
customthe solvent was evaporated in vacuum
customthe residue was crystallized from n-hexane

Sources & evidence

ORD record: ord-985c438dc6124981a14bb6d0281246b1
Source dataset: uspto-grants-2015_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09166177B2

Reaction notes

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