Triphenylphosphine → 4-Methylene-3,4-dihydro-2H-pyrano[3,2-b]pyridine

HRID 7128

Reaction equation

HRID 7128 reaction equation
Br[C:2]1[C:7]([O:8][CH2:9][CH2:10][CH:11]=[CH2:12])=[CH:6][CH:5]=[CH:4][N:3]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C([O-])(=O)C.[K+]>O.[Cl-].C([N+](CC)(CC)CC)C.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[CH2:12]=[C:11]1[C:2]2=[N:3][CH:4]=[CH:5][CH:6]=[C:7]2[O:8][CH2:9][CH2:10]1

Participants

6

Reactant 3

HCID 11776TriphenylphosphineHCID 517044Potassium AcetateHCID 220185632-Bromo-3-(but-3-en-1-yloxy)pyridine

Product 1

HCID 220186834-Methylene-3,4-dihydro-2H-pyrano[3,2-b]pyridineYield 52.8%

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 16211205Tetraethylammonium chloride monohydrateCatalyst

Conditions

Temperature
110 °C

Procedure

A reaction tube was charged with 2-Bromo-3-but-3-enyloxy-pyridine (106 mg, 0.45 mmol), triphenylphosphine (35 mg, 0.133 mmol), palladium acetate (10 mg, 0.044 mmol), potassium acetate (223 mg, 2.27 mmol), tetraethylammonium chloride hydrate (151 mg, 0.91 mmol) and degassed DMF (2 mL). A rubber septum was used to seal the tube and the contents were then flushed several times with argon, then closed tightly with a cap. The mixture was heated at 110° C. under argon for 18 hours, cooled to room temperature then diluted with 200 mL ethyl acetate. The organic layer was washed with sat. NaHCO3, then brine and dried over Na2SO4. Evaporation of the solvent and purification of the residue by flash chromatography on silica gel, using 5% ethyl acetate in hexanes, afforded the title compound (35 mg, 52%) as white solid. 1H NMR (CDCl3) □ 2.79–2.84 (m, 2H), 4.25 (t, 2H, J=5.7 Hz), 5.06–5.08 (m, 1H), 6.19 (d, 1H, J=1.6 Hz), 7.08–7.17 (m, 2H), 8.20 (dd, 1H, J=1.6, 4.7 Hz); ES-MS m/z 148.0 (M+H).

Workup

  1. customdegassed DMF (2 mL)
  2. customto seal the tube
  3. customthe contents were then flushed several times with argon
  4. customclosed tightly with a cap
  5. temperaturecooled to room temperature
  6. additionthen diluted with 200 mL ethyl acetate
  7. washThe organic layer was washed with sat. NaHCO3
  8. dry with materialbrine and dried over Na2SO4
  9. customEvaporation of the solvent and purification of the residue by flash chromatography on silica gel

Sources & evidence

ORD record
ord-fb8e651edbfe42a48a8f431330505aa7
Source dataset
uspto-grants-2006_08
Patent number
US07084155B2

Linked notes

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