Triphenylphosphine → 6-bromo-4-methylene-3,4-dihydro-2H-pyrano[3,2-b]pyridine

HRID 2279270

Reaction equation

HRID 2279270 reaction equation
C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.CC([O-])=O.[K+].Br[C:26]1[C:31]([O:32][CH2:33][CH2:34][CH:35]=[CH2:36])=[CH:30][CH:29]=[C:28]([Br:37])[N:27]=1>CN(C=O)C.C(OCC)(=O)C.CC([O-])=O.CC([O-])=O.[Pd+2]>[Br:37][C:28]1[N:27]=[C:26]2[C:35](=[CH2:36])[CH2:34][CH2:33][O:32][C:31]2=[CH:30][CH:29]=1

Participants

7

Reactant 3

HCID 11776TriphenylphosphineHCID 517044Potassium AcetateHCID 584840892,6-Dibromo-3-(but-3-enyloxy)pyridine

Product 1

HCID 584840716-bromo-4-methylene-3,4-dihydro-2H-pyrano[3,2-b]pyridineYield 22.4%

Reagents, catalysts & solvents 3

HCID 167845palladium(II) acetateCatalystHCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
105 °C

Procedure

To a stirred mixture of PPh3 (67.6 g, 0.258 mol), KOAc (42 g, 0.43 mol), Pd(OAc)2 (1.94 g, 8.6 mmol) and Et4NCI (28.6 g, 0.172 mmol), was added 2,6-dibromo-3-(but-3-enyloxy) pyridine (26.4 g, 0.086 mol) in anhydrous DMF (300 mL). The mixture was heated at 105° C. for 18 hours. After cooling to ambient temperature, the mixture was dissolved in Ethyl acetate, washed with water and brine, dried over Na2SO4, and concentrated in vacuo. The crude product was purified by silica gel chromatography (petroleum) to afford the title compound as oil (4.35 g, 22%). 1H NMR (400 Mz, DMSO-d6): δ 2.74 (t, J=5.4, 2H); 4.20 (t, J=6, 2H); 5.12 (s, 1H); 5.98 (s, 1H); 7.24 (d, J=7.5, 1H); 7.40 (d, J=7.5, 1H).

Workup

  1. temperatureAfter cooling to ambient temperature
  2. washwashed with water and brine
  3. dry with materialdried over Na2SO4
  4. concentrationconcentrated in vacuo
  5. customThe crude product was purified by silica gel chromatography (petroleum)

Sources & evidence

ORD record
ord-909bda4f2f054af3b22c56facb8f924b
Source dataset
uspto-grants-2015_09
Patent number
US09133218B2

Linked notes

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