Neopentyl glycol → 2-(4-Bromophenyl)-5,5-dimethyl-1,3-dioxane

HRID 1824624Notes

Reaction equation

HRID 1824624 reaction equation
[Br:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=[O:7])=[CH:4][CH:3]=1.[CH3:10][C:11]([CH2:15]O)([CH2:13][OH:14])[CH3:12]>C1(C)C=CC=CC=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>[Br:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]2[O:14][CH2:13][C:11]([CH3:15])([CH3:12])[CH2:10][O:7]2)=[CH:4][CH:3]=1

Participants

5

Reactant 2

HCID 31344Neopentyl glycolHCID 707414-Bromobenzaldehyde

Product 1

HCID 137145152-(4-Bromophenyl)-5,5-dimethyl-1,3-dioxaneYield 64%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 1140TolueneSolvent

Procedure

The following describes an improved procedure at three times larger scale in much shorter time compared with the literature (Hewlins et al. (1986) J. Chem. Res. (M), 8: 2645–2696). 4-Bromobenzaldehyde (3.00 g, 16.2 mmol), neopentylglycol (1.86 g, 17.9 mmol) and p-toluenesulfonic acid (50 mg, 0.3 mmol) were dissolved in toluene (30 mL) and the solution was refluxed for 3 h. Then the solution was cooled to rt, washed twice with aq NaHCO3 (10%), twice with water and dried (Na2SO4). The solvent was evaporated and the oily residue was crystallized from hexanes, affording colorless needles (2.81 g, 64%). 13C NMR (APT) δ 21.7 (−), 22.9 (−), 30.1 (+), 77.5 (+), 100.8 (−), 122.7 (+), 127.8 (−), 131.3 (−), 137.5 ((+)).

Workup

  1. temperaturethe solution was refluxed for 3 h
  2. washwashed twice with aq NaHCO3 (10%), twice with water
  3. dry with materialdried (Na2SO4)
  4. customThe solvent was evaporated
  5. customthe oily residue was crystallized from hexanes

Sources & evidence

ORD record
ord-aaa37536532c43448a2d3f7cba9e7a4a
Source dataset
uspto-grants-2006_05
Patent number
US07042755B1

Reaction notes

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