4-Methoxymandelic acid → 2-Trimethylsilylethyl 4-methoxymandelate

HRID 1534093Notes

Reaction equation

HRID 1534093 reaction equation
[CH3:1][O:2][C:3]1[CH:13]=[CH:12][C:6]([CH:7]([OH:11])[C:8]([OH:10])=[O:9])=[CH:5][CH:4]=1.[CH3:14][Si:15]([CH3:29])([CH3:28])[CH2:16][CH2:17]N=C(O)N(C(C)C)C(C)C>O1CCOCC1.C(OCC)(=O)C>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]([CH:7]([OH:11])[C:8]([O:10][CH2:17][CH2:16][Si:15]([CH3:29])([CH3:28])[CH3:14])=[O:9])=[CH:12][CH:13]=1

Participants

5

Reactant 2

HCID 1120564-Methoxymandelic acidHCID 178457954HCID 178457954, compound

Product 1

HCID 137057282-Trimethylsilylethyl 4-methoxymandelateYield 72%

Reagents, catalysts & solvents 2

HCID 8857Ethyl AcetateSolventHCID 312751,4-DioxaneSolvent

Procedure

To a solution of 4-methoxymandelic acid (2.00 g, 10.978 mmol) in 55 mL of dioxane at 90° C. is added 2-trimethylsilylethyl-N,N-diisopropyl-pseudourea. The resulting solution is refluxed for about 8 hours. After cooling the mixture is diluted with 50 mL of ethyl acetate, filtered, washed with saturated aqueous sodium bicarbonate followed by brine, dried over magnesium sulfate, and concentrated. The resulting residue is chromatographed on silica gel (9/1 hexanes/ethyl acetate) to give the title compound as an oil: 2.24 g, 72% yield. 1H NMR (300 MHz, CDCl3): 7.32 (d, J=8.8, 2 H), 6.89 (d, J=8.8, 2 H), 5.08 (d, J=5.6, 1 H), 4.38-4.17 (m, 2 H), 3.81 (s, 3 H), 3.41 (d, J=5.6, 1 H), 0.96 (m, 2 H), 0.01 (s, 9 H).

Workup

  1. temperatureThe resulting solution is refluxed for about 8 hours
  2. temperatureAfter cooling the mixture
  3. filtrationfiltered
  4. washwashed with saturated aqueous sodium bicarbonate
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated
  7. customThe resulting residue is chromatographed on silica gel (9/1 hexanes/ethyl acetate)

Sources & evidence

ORD record
ord-037917923f3e438fbf6b7a03f3e88f07
Source dataset
uspto-grants-1992_02
Patent number
US05087631

Reaction notes

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