(E)-1-Bromo-4-(2-iodovinyl)benzene → Ethyl 2-(4-bromophenyl)pyrazolo[1,5-a]pyridine-5-carboxylate

HRID 1475934

Reaction equation

HRID 1475934 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[CH:11]=[CH:10][N+:9](=[N:12]C(=O)C2C=CC=CC=2)[CH2:8][CH:7]=1)=[O:5])[CH3:2].[Br:21][C:22]1[CH:27]=[CH:26][C:25](/[CH:28]=[CH:29]/I)=[CH:24][CH:23]=1>[Pd](Br)Br.[O-]S(C(F)(F)F)(=O)=O.[Ag+].O1CCOCC1>[Br:21][C:22]1[CH:27]=[CH:26][C:25]([C:28]2[CH:29]=[C:8]3[CH:7]=[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])[CH:11]=[CH:10][N:9]3[N:12]=2)=[CH:24][CH:23]=1

Participants

6

Reactant 2

HCID 12051842(E)-1-Bromo-4-(2-iodovinyl)benzeneHCID 867112174-Ethoxycarbonyl-N-benzoyliminopyridinium

Product 1

HCID 68276034Ethyl 2-(4-bromophenyl)pyrazolo[1,5-a]pyridine-5-carboxylateYield 54%

Reagents, catalysts & solvents 3

HCID 76223Silver(I) trifluoromethanesulfonateCatalystHCID 83469Palladium bromide (PdBr2)CatalystHCID 312751,4-DioxaneSolvent

Conditions

Temperature
127.5 °C

Procedure

Related procedures are described in Org. Lett. 2010, 12, 516): 4-Ethoxycarbonyl-N-benzoyliminopyridinium ylid (JOC 2003, 68, 7119) (3.50 g, 13.0 mmol), para-tris-methoxyphenylphosphine (686 mg, 1.95 mmol), Palladium (II) bromide (173 mg, 0.65 mmol), silver triflate (8.93 g, 39.0 mmol) and (E)-1-Bromo-4-(2-iodovinyl)benzene (Org. Lett. 2008, 10, 5485) (4.02 g, 13.0 mmol) were placed in a 250 mL round bottom flask equipped a with magnetic stirrer. Dioxane (52 mL) was added. The mixture was degassed by bubbling nitrogen for 10 minutes with vigorous stirring and heated to 125-130° C. for 15-20 h. The mixture was then cooled to room temperature, diluted with CH2Cl2, filtered over Celite. The organic layer was then washed with saturated aqueous sodium bicarbonate and the organic phase was concentrated under reduced pressure. The crude product was triturated with methanol to afford 2.40 g (54%) of the title compound. LCMS m/z 345.0, 347.0 (M+H)+, ret. time=3.05 min.

Workup

  1. customwere placed in a 250 mL round bottom flask
  2. customequipped a with magnetic stirrer
  3. customThe mixture was degassed
  4. customby bubbling nitrogen for 10 minutes
  5. temperatureThe mixture was then cooled to room temperature
  6. additiondiluted with CH2Cl2
  7. filtrationfiltered over Celite
  8. washThe organic layer was then washed with saturated aqueous sodium bicarbonate
  9. concentrationthe organic phase was concentrated under reduced pressure
  10. customThe crude product was triturated with methanol

Sources & evidence

ORD record
ord-8d9afb91e3aa4b77aed1ebcef3454d46
Source dataset
uspto-grants-2015_04
Patent number
US09018395B2

Linked notes

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