Triethylamine → 2-Bromo-5-phenylethynyl-pyrazine

HRID 1917579Notes

Reaction equation

HRID 1917579 reaction equation
[Br:1][C:2]1[CH:7]=[N:6][C:5](I)=[CH:4][N:3]=1.[C:9]1([C:15]#[CH:16])[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.C(N(CC)CC)C.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C1COCC1.C(OCC)(=O)C.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.Cl[Pd]Cl.[Cu]I>[Br:1][C:2]1[CH:7]=[N:6][C:5]([C:16]#[C:15][C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)=[CH:4][N:3]=1

Participants

9

Reactant 4

HCID 8471TriethylamineHCID 10821PhenylacetyleneHCID 11776TriphenylphosphineHCID 219312002-Bromo-5-iodopyrazine

Product 1

HCID 575167832-Bromo-5-phenylethynyl-pyrazineYield 23.5%

Reagents, catalysts & solvents 4

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 6102075Dichlorobis(triphenylphosphine)palladiumCatalystHCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
60 °C

Procedure

To a solution of 2-bromo-5-iodopyrazine (500 mg, 1.76 mmol), phenylacetylene (224 mg, 241 μL, 2.19 mmol, 1.25 equiv.), triethylamine (533 mg, 734 μL, 5.27 mmol, 3 equiv.), bis(triphenylphosphine)palladium (II) chloride (73.9 mg, 0.105 mmol, 0.06 equiv.) and triphenyl-phosphine (13.8 mg, 0.053 mmol, 0.03 equiv.) in 10 ml of THF was added under an Argon atmosphere copper (I) iodide (10.0 mg, 0.053 mmol, 0.03 equiv.). The suspension was warmed to 60° C. overnight, taken up in 5 ml of ethyl acetate and adsorbed on 4 g of silica. Purification by flash chromatography on silicagel using a 2:1 ethyl acetate/heptane mixture yielded the title compound as a light brown solid (107 mg, 23% yield). The material was directly used in the next step without further characterization.

Workup

  1. customPurification by flash chromatography on silicagel

Sources & evidence

ORD record
ord-306a65da54b94c209645201c4feaa7b5
Source dataset
uspto-grants-2013_12
Patent number
US08618296B2

Reaction notes

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