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

HRID 2111455Notes

Reaction equation

HRID 2111455 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-a31b49f43dae4b6785eec479c10da7dc
Source dataset
uspto-grants-2009_04
Patent number
US07518905B2

Reaction notes

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