p-Toluenesulfonic acid → 4-Bromo-3-[1,3]dioxan-2-yl-phenol

HRID 1914278Notes

Reaction equation

HRID 1914278 reaction equation
[Br:1][C:2]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][C:3]=1[CH:4]=[O:5].[CH2:11]1C[O:14][CH2:13][CH2:12]1.C(O)CCO.CC1C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[Br:1][C:2]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][C:3]=1[CH:4]1[O:14][CH2:13][CH2:12][CH2:11][O:5]1

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 8028TetrahydrofuranHCID 104421,3-PropanediolHCID 3871792-Bromo-5-hydroxybenzaldehyde

Product 1

HCID 215731464-Bromo-3-[1,3]dioxan-2-yl-phenol

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

To the solution of 2-bromo-5-methoxy-benzaldehyde (10 g, 46.5 mmol) at −78° C. is added BBr3 (25 g, 93.75 mmol) and allowed to warm to room temperature. After 2 h, the reaction is quenched with water and extracted with ethyl acetate. The combined organic layers are washed with water, brine, dried over MgSO4, concentrated and purified by column chromatography to afford 3.6 g of 2-bromo-5-hydroxy-benzaldehyde. To the solution of 2-bromo-5-hydroxy-benzaldehyde (1.45 g, 7.2 mmol in benzene (30 ml) and THF (6 ml) is added 1,3-propanediol (2.74 g, 36 mmol) and TsOH (37 mg, 0.22 mmol). The mixture is refluxed for 24. After cooling down, the solvent is evaporated. The residue is loaded on silica and purified by column chromatography to afford the titled compound (2.3 g) as brown oil.

Workup

  1. temperatureThe mixture is refluxed for 24
  2. temperatureAfter cooling down
  3. customthe solvent is evaporated
  4. custompurified by column chromatography

Sources & evidence

ORD record
ord-b0a9cd9e4983405697a8bef5923a672d
Source dataset
uspto-grants-2013_12
Patent number
US08609892B2

Reaction notes

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