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

HRID 2266129Notes

Reaction equation

HRID 2266129 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-6hydroxy-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-18594b51a1d54133ab132348ab66a4e6
Source dataset
uspto-grants-2010_12
Patent number
US07858632B2

Reaction notes

Loading…