Hydrochloric Acid → 2-(10,11-Dihydro-dibenzo[a,d]cyclohepten-5-ylidenemethyl)-phenylboronic acid

HRID 2218716Notes

Reaction equation

[Li]CCCC.Br[C:7]1[CH:28]=[CH:27][CH:26]=[CH:25][C:8]=1[CH:9]=[C:10]1[C:16]2[CH:17]=[CH:18][CH:19]=[CH:20][C:15]=2[CH2:14][CH2:13][C:12]2[CH:21]=[CH:22][CH:23]=[CH:24][C:11]1=2.[B:29](OC(C)C)([O:34]C(C)C)[O:30]C(C)C.Cl>C1COCC1>[CH:21]1[C:12]2[CH2:13][CH2:14][C:15]3[CH:20]=[CH:19][CH:18]=[CH:17][C:16]=3[C:10](=[CH:9][C:8]3[CH:25]=[CH:26][CH:27]=[CH:28][C:7]=3[B:29]([OH:34])[OH:30])[C:11]=2[CH:24]=[CH:23][CH:22]=1

Participants

Conditions

Temperature: -78 °C

Procedure

Add n-BuLi (1.6M in hexanes, 12.98 Ml, 20.76 mmol) portionwise (exothermic) to a solution of 5-(2-bromo-benzylidene)-10,11-dihydro-5H-dibenzo[a,d]cycloheptene (5.00 g, 13.84 mmol) in dry THF (50 Ml) at −78° C. under N2. Let stir at −78° C. for 30 min, then add triisopropyl borate (5.21 g, 27.68 mmol) and warm up to room temperature overnight. Add 50 Ml 1.00N HCl and stir for 15 min. Extract into ethyl acetate, dry (MgSO4) and concentrate organics to a brown foam. Recrystallize from boiling hexanes, then chromatograph on silica gel (40 g), eluting with 20% to 50% ethyl acetate/hexanes to afford the title compound as a white foam, mp 134.1° C. MS (ES) 325 (M−H); HPLC shows 82% purity.

Workup

stirringstir for 15 min
extractionExtract into ethyl acetate
dry with materialdry (MgSO4)
concentrationconcentrate organics to a brown foam
customRecrystallize
washchromatograph on silica gel (40 g), eluting with 20% to 50% ethyl acetate/hexanes

Sources & evidence

ORD record: ord-d113203c8ca34e238d0b0a89847b6841
Source dataset: uspto-grants-2008_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07411072B2

Reaction notes

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