Boron tribromide → 4-[3,5-Dimethyl-4-hydroxyphenyl]butanol

HRID 893001Notes

Reaction equation

HRID 893001 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]([CH2:11][CH2:12][CH2:13][CH2:14][OH:15])[CH:5]=[C:6]([CH3:10])[C:7]=1[O:8]C.B(Br)(Br)Br>C(Cl)Cl>[CH3:1][C:2]1[CH:3]=[C:4]([CH2:11][CH2:12][CH2:13][CH2:14][OH:15])[CH:5]=[C:6]([CH3:10])[C:7]=1[OH:8]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 198945574-[3,5-Dimethyl-4-methoxyphenyl)butanol

Product 1

HCID 198946424-[3,5-Dimethyl-4-hydroxyphenyl]butanol

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of 4-[3,5-dimethyl-4-methoxyphenyl]butanol (PREPARATION NA-14, 4.96 g), boron tribromide (1.0M in methylene chloride, 47 ml) in methylene chloride (200 ml) is stirred at -70° and then allowed to warm to 20°-25° over 4 hr. The reaction did not begin until the reaction reached room temperature. The reaction mixture is partitioned between methylene chloride and aqueous sodium bicarbonate. The organic phase is dried over sodium sulfate and concentrated to give the phenol which had a consistent NMR. A sample of the phenol (5.00 g) is dissolved in methylene chloride (100 ml) and is treated at 0° with triethylamine (6.28 g) and methanesulfonyl chloride (7.09 g). After 3 hr, the reaction mixture is partitioned between methylene chloride and aqueous sodium bicarbonate. The organic phase is dried over sodium sulfate and concentrated to give the title compound which had an NMR consistent for the bis-mesylate.

Workup

  1. temperatureto warm to 20°-25° over 4 hr
  2. customreached room temperature
  3. customThe reaction mixture is partitioned between methylene chloride and aqueous sodium bicarbonate
  4. dry with materialThe organic phase is dried over sodium sulfate
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-b64877304b1b497cb485379f106afb50
Source dataset
uspto-grants-1992_06
Patent number
US05120843

Reaction notes

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