Boron tribromide → 1-(2-Chloro-4,6-dihydroxyphenyl)-2-(4-hydroxyphenyl)ethanone

HRID 1765402Notes

Reaction equation

HRID 1765402 reaction equation
B(Br)(Br)Br.[Cl:5][C:6]1[CH:11]=[C:10]([O:12]C)[CH:9]=[C:8]([O:14]C)[C:7]=1[C:16](=[O:26])[CH2:17][C:18]1[CH:23]=[CH:22][C:21]([O:24]C)=[CH:20][CH:19]=1>ClCCCl>[Cl:5][C:6]1[CH:11]=[C:10]([OH:12])[CH:9]=[C:8]([OH:14])[C:7]=1[C:16](=[O:26])[CH2:17][C:18]1[CH:23]=[CH:22][C:21]([OH:24])=[CH:20][CH:19]=1

Participants

4

Reactant 2

HCID 25134Boron tribromide2×HCID 211070811-(2-Chloro-4,6-dimethoxyphenyl)-2-(4-methoxyphenyl)ethanone

Product 1

HCID 211070801-(2-Chloro-4,6-dihydroxyphenyl)-2-(4-hydroxyphenyl)ethanoneYield 74.4%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
70 °C

Procedure

Boron tribromide (1.0 M soultion in dichloromethane, 5 mL) was added drop-wise to a solution of 1-(2-chloro-4,6-dimethoxyphenyl)-2-(4-methoxyphenyl)ethanone (1.34 g) in 1,2-dichloroethane (25 mL). The solution was heated to 70° C. for 24 h, cooled to room temperature and stirred for 90 h. Additional boron tribromide (1.0 M solution in dichloromethane, 5 mL) was added drop-wise, heating to 70° C. for 12 h. The solution was cooled to −45° C., quenched with methanol (45 mL) and concentrated in vacuo. The solids were redissolved in ethyl acetate (40 mL) and washed with saturated sodium bicarbonate (2×25 mL), 1.2 N HCl (2×25 mL) and brine (2×25 mL), dried over Na2SO4, filtered and concentrated in vacuo. The resulting oil was triturated with dichloromethane (150 mL) to provide the title compound (866 mg). 1H NMR (DMSO-d6): 10.35 (s br, 1H), 10.02 (s br, 1H), 9.28 (s br, 1H), 6.94 (d, 2H, J=8.4 Hz), 6.65 (d, 2H, J=8.7 Hz), 6.27 (dd, 2H, J=10.2 Hz, 2.1 Hz), 3.92 (s, 2H); MS: 279 (MH+).

Workup

  1. temperaturecooled to room temperature
  2. temperatureheating to 70° C. for 12 h
  3. temperatureThe solution was cooled to −45° C.
  4. customquenched with methanol (45 mL)
  5. concentrationconcentrated in vacuo
  6. dissolutionThe solids were redissolved in ethyl acetate (40 mL)
  7. washwashed with saturated sodium bicarbonate (2×25 mL), 1.2 N HCl (2×25 mL) and brine (2×25 mL)
  8. dry with materialdried over Na2SO4
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo
  11. customThe resulting oil was triturated with dichloromethane (150 mL)

Sources & evidence

ORD record
ord-ed1b6518fc9c4de49198079b31760b34
Source dataset
uspto-grants-2007_06
Patent number
US07226945B2

Reaction notes

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