Boron tribromide → 1,4-Benzodioxin-6-ol, 2,3-dihydro-5-(1-methylethyl)-

HRID 81802Notes

Reaction equation

HRID 81802 reaction equation
[CH:1]([C:4]1[C:13]2[O:12][CH2:11][CH2:10][O:9][C:8]=2[CH:7]=[CH:6][C:5]=1[O:14]C)([CH3:3])[CH3:2].B(Br)(Br)Br>C(Cl)Cl>[CH:1]([C:4]1[C:13]2[O:12][CH2:11][CH2:10][O:9][C:8]=2[CH:7]=[CH:6][C:5]=1[OH:14])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 59598692HCID 59598692, compound

Product 1

HCID 451220301,4-Benzodioxin-6-ol, 2,3-dihydro-5-(1-methylethyl)-Yield 65.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 5-isopropyl-6-methoxy-2,3-dihydro-benzo[1,4]dioxine (1.011 g, 4.9 mmol) in 15 ml CH2Cl2 at −78° C. was added BBr3 (7.3 ml, 7.3 mmol). The solution was allowed to warm to room temperature. After 16 hours the solution was cooled to −78° C., quenched with H2O, warmed to room temperature and extracted with CH2Cl2. The combined organics were washed with brine, dried over MgSO4, filtered and concentrated in vacuo. Purification via flash chromatography (7:3 hexane/ethyl acetate) afforded 5-isopropyl-6 hydroxy-2,3-dihydro-benzo[1,4]dioxine (0.622 g, 63%) as a pale yellow oil.

Workup

  1. temperatureAfter 16 hours the solution was cooled to −78° C.
  2. customquenched with H2O
  3. temperaturewarmed to room temperature
  4. extractionextracted with CH2Cl2
  5. washThe combined organics were washed with brine
  6. dry with materialdried over MgSO4
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. customPurification via flash chromatography (7:3 hexane/ethyl acetate)

Sources & evidence

ORD record
ord-9bd3a4ed0f9a428bb59d8797fb015763
Source dataset
uspto-grants-2014_09
Patent number
US08846705B2

Reaction notes

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