Trimethylsilylacetylene → Furo(3,2-b)pyridine

HRID 1192401Notes

Reaction equation

HRID 1192401 reaction equation
Br[C:2]1[C:7]([O:8][C:9](=O)[CH3:10])=[CH:6][CH:5]=[CH:4][N:3]=1.[Si](C#C)(C)(C)C>C1COCC1.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.[Cu]I>[O:8]1[C:7]2[C:2](=[N:3][CH:4]=[CH:5][CH:6]=2)[CH:10]=[CH:9]1

Participants

6

Reactant 2

HCID 66111TrimethylsilylacetyleneHCID 154718962-Bromopyridin-3-yl acetate

Product 1

HCID 12210217Furo(3,2-b)pyridineYield 21.3%

Reagents, catalysts & solvents 3

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 178418476HCID 178418476, compoundCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of PdCl2(PPh3)2 (1.4 g, 2.0 mmol) and CuI (0.4 g, 2.1 mmol) in TEA (100 mL) and THF (200 mL) under nitrogen was added a mixture of 2-bromo-3-acetoxy-pyridine (13.1 g, 60.6 mmol) and TMS-acetylene (7.0 g, 71 mmol) in THF (100 mL) in one portion. The mixture was stirred at room temperature for 1 hour. Then quenched with saturated NaHCO3 (50 mL) and MeOH (50 mL). The mixture was stirred at 80° C. for 2 hours. After cooling, the mixture was extracted with ether. The organic phase was dried and concentrated. The residue was subject to column chromatography to afford Furo[3,2-b]pyridine (1.54 g, 21%). 1H NMR (CDCl3, 400 MHz) δ 8.55 (m, 1H), 7.84 (m, 1H), 7.75 (m, 1H), 7.72 (m, 1H), 6.99 (m, 1H).

Workup

  1. customThen quenched with saturated NaHCO3 (50 mL) and MeOH (50 mL)
  2. stirringThe mixture was stirred at 80° C. for 2 hours
  3. temperatureAfter cooling
  4. extractionthe mixture was extracted with ether
  5. customThe organic phase was dried
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-00eaea0f8b22491e8a8e638b87415e4d
Source dataset
uspto-grants-2014_03
Patent number
US08680114B2

Reaction notes

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