Boron tribromide → 4,4'-Dihydroxybenzil

HRID 1620357Notes

Reaction equation

C[O:2][C:3]1[CH:8]=[CH:7][C:6]([C:9](=[O:20])[C:10]([C:12]2[CH:17]=[CH:16][C:15]([O:18]C)=[CH:14][CH:13]=2)=[O:11])=[CH:5][CH:4]=1.B(Br)(Br)Br>C(Cl)Cl>[OH:2][C:3]1[CH:4]=[CH:5][C:6]([C:9](=[O:20])[C:10]([C:12]2[CH:17]=[CH:16][C:15]([OH:18])=[CH:14][CH:13]=2)=[O:11])=[CH:7][CH:8]=1

Participants

Conditions

Temperature: -78 °C

Procedure

1,2-bis(4-methoxyphenyl)ethane-1,2-dione (5 g, 18.52 mmol) was dissolved in CH2Cl2 and cooled to −78° C. (solid occurred again). BBr3 (8.3 m, 87.82 mmol) was added and mixture was allowed to warm to room temperature and stirred for 15 hrs. TLC check showed 1,2-bis(4-methoxyphenyl)ethane-1,2-dione completely disappeared. The reaction mixture was poured into ice, extracted by EtOAc, washed with NaCl solution, dried over MgSO4. The solvent was removed by vacuum, and the residue was purified by column chromatography to give compound 5, 1,2-bis(4-hydroxyphenyl)ethane-1,2-dione, as confirmed by the following nuclear magnetic resonance (NMR) data obtained therefrom: 1H NMR (500 MHz, DMSO): δ 10.8 (s, 2H), 7.71 (d, J=8.8 MHz, 4H), 6.90 (d, J=8.8 MHz, 4H) ppm.

Workup

temperatureto warm to room temperature
additionThe reaction mixture was poured into ice
extractionextracted by EtOAc
washwashed with NaCl solution
dry with materialdried over MgSO4
customThe solvent was removed by vacuum
customthe residue was purified by column chromatography

Sources & evidence

ORD record: ord-8f58a185f81d4038ba6863ed558e69ef
Source dataset: uspto-grants-2014_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08772443B2

Reaction notes

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