Acetic Acid → Methyl 4-ethynylbenzoate

HRID 1264226Notes

Reaction equation

HRID 1264226 reaction equation
[CH3:1][O:2][C:3](=[O:16])[C:4]1[CH:9]=[CH:8][C:7]([C:10]#[C:11][Si](C)(C)C)=[CH:6][CH:5]=1.[F-].C([N+](CCCC)(CCCC)CCCC)CCC.C(O)(=O)C>C1COCC1.C(OCC)(=O)C>[CH3:1][O:2][C:3](=[O:16])[C:4]1[CH:9]=[CH:8][C:7]([C:10]#[CH:11])=[CH:6][CH:5]=1

Participants

6

Reactant 3

HCID 176Acetic AcidHCID 640161Methyl 4-trimethylsilylethynylbenzoateHCID 2724141Tetrabutylammonium Fluoride

Product 1

HCID 640163Methyl 4-ethynylbenzoateYield 79.9%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of 4-trimethylsilanylethynyl-benzoic acid methyl ester (4.65 g, 20 mmol) (reference example 47) in THF (40 mL) is added (1M) tetrabutylammonium fluoride (3 mL, 30 mmol) and acetic acid (1.9 mL, 33 mmol). The resulting solution is stirred for 25 min, diluted with ethyl acetate, washed with water and brine, dried over MgSO4 and concentrated. The residue is purified by flash chromatography (eluting with 10% ether, 10% dichloromethane in hexanes) to give 2.56 g of title compound as a pale yellow solid. 1H NMR (CDCl3) δ 3.23 (s, 1H), 3.92 (s, 3H), 7.55 (d, J=8 Hz, 2H), 8.00 (d, J=8 Hz, 2H). MS (EI) m/z 160 (M+).

Workup

  1. washwashed with water and brine
  2. dry with materialdried over MgSO4
  3. concentrationconcentrated
  4. customThe residue is purified by flash chromatography (eluting with 10% ether, 10% dichloromethane in hexanes)

Sources & evidence

ORD record
ord-bb35abd014d44d7588841438e329fddb
Source dataset
uspto-grants-2003_04
Patent number
US06541505B1

Reaction notes

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