Methanol → 1,3-Dioxane, 5-(2-bromoethyl)-2,2-dimethyl-

HRID 1368672Notes

Reaction equation

HRID 1368672 reaction equation
O[CH2:2][CH2:3][CH:4]1[CH2:9][O:8][C:7]([CH3:11])([CH3:10])[O:6][CH2:5]1.C(Br)(Br)(Br)[Br:13].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CO>CN(C)C=O>[Br:13][CH2:2][CH2:3][CH:4]1[CH2:9][O:8][C:7]([CH3:11])([CH3:10])[O:6][CH2:5]1

Participants

6

Reactant 4

HCID 887MethanolHCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 118160112-(2,2-Dimethyl-1,3-dioxan-5-yl)ethanol

Product 1

HCID 1789881,3-Dioxane, 5-(2-bromoethyl)-2,2-dimethyl-Yield 40%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To an ice-cooled solution of 5-(2-hydroxyethyl)-2,2-dimethyl-1,3-dioxan (1.92 g, 12 mmol) and carbon tetrabromide (7.96 g, 24 mmol) in dimethylformamide (100 ml), triphenyl-phosphine (6.30 g, 24 mmol) was added and the solution was left at 4° C. overnight. To this solution methanol (20 ml) was added and the solvent was then evaporated under reduced pressure. The residue was purified by column chromatography on silica gel, eluting with hexane-acetone (12:1) to afford 5-(2-bromoethyl)-2,2-dimethyl-1,3-dioxan as a clear colourless liquid (0.89 g, 40%); νmax (film) 2940, 1370, 1270, 1260, 1200, and 1070 cm−1; δH (CDCl3) 1.42 (6H, s, C(CH3)2), 1.94 (3H, m, CHCH2CH2Br), 3.43 (2H, t, J 7 Hz, CH2Br), and 3.5-4.1 (4H, m, 2×CH2O); (Found: C, 42.84; H, 6.93%. C8H15BrO2 requires: C, 43.07; H, 6.78%. [M−CH3] found 207.0024; C7H12BrO2 requires 207.0021).

Workup

  1. additionwas added
  2. customthe solvent was then evaporated under reduced pressure
  3. customThe residue was purified by column chromatography on silica gel
  4. washeluting with hexane-acetone (12:1)

Sources & evidence

ORD record
ord-661415b10ed54c81afc1fd5bf1a5f508
Source dataset
uspto-grants-2003_06
Patent number
US06573378B1

Reaction notes

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