Trimethylsilylacetylene → Methyl 4-hydroxy-3-[(trimethylsilyl)ethynyl]benzoate

HRID 2181653Notes

Reaction equation

HRID 2181653 reaction equation
[OH:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][C:3]=1I.[CH3:13][Si:14]([C:17]#[CH:18])([CH3:16])[CH3:15]>C1COCC1.C(Cl)(Cl)Cl.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[OH:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][C:3]=1[C:18]#[C:17][Si:14]([CH3:16])([CH3:15])[CH3:13]

Participants

6

Reactant 2

HCID 66111TrimethylsilylacetyleneHCID 11346465Methyl 4-hydroxy-3-iodobenzoate

Product 1

HCID 22481707Methyl 4-hydroxy-3-[(trimethylsilyl)ethynyl]benzoateYield 50.3%

Reagents, catalysts & solvents 3

HCID 178418476HCID 178418476, compoundCatalystHCID 6212ChloroformSolvent2×HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
50 °C

Procedure

Methyl 4-hydroxy-3-iodobenzoate (5.56 g, 20 mmol) is combined with trimethylsilylacetylene (3.96 mL, 28 mmol), bis(triphenylphosphine)palladium dichloride (414 mg, 0.6 mmol) and cuprous iodide (57 mg, 0.3 mmol) in THF (20 mL)/CHCl3 (40 mL) in a dry flask, under nitrogen. TEA (8.7 mL, 62.3 mmol) is added and the mixture heated to 50° C. for 4 h. The mixture is diluted with CHCl3 (60 mL), washed with 5% HCl (2×40 mL), dried (MgSO4) and concentrated to a brown solid. The crude material is adsorbed onto silica gel and chromatographed over 200 g silica gel, eluting with 15% EtOAc/hexane (2 L) followed by 20% EtOAc/hexane (1 L). Fractions are combined and concentrated to afford 2.50 g (50%) of methyl 4-hydroxy-3-[(trimethylsilyl)ethynyl]benzoate as a yellow solid. HRMS (FAB) calcd for C13H16O3SI+H: 249.0947, found 249.0955 (M+H)+.

Workup

  1. washwashed with 5% HCl (2×40 mL)
  2. dry with materialdried (MgSO4)
  3. concentrationconcentrated to a brown solid
  4. customchromatographed over 200 g silica gel
  5. washeluting with 15% EtOAc/hexane (2 L)
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-8c16eae3e0bf4e99a908811c188523f7
Source dataset
uspto-grants-2005_05
Patent number
US06894042B2

Reaction notes

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