Diethyl Ether → 2-(2-Iodophenyl)pyrazine

HRID 735338Notes

Reaction equation

HRID 735338 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[I:8].C([Sn](CCCC)(CCCC)[C:14]1[CH:19]=[N:18][CH:17]=[CH:16][N:15]=1)CCC.C(OCC)C>O1CCCC1.[Cu]I.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>[I:8][C:3]1[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=1[C:14]1[CH:19]=[N:18][CH:17]=[CH:16][N:15]=1

Participants

7

Reactant 3

HCID 3283Diethyl EtherHCID 114151-Bromo-2-iodobenzeneHCID 27373162-(Tributylstannyl)pyrazine

Product 1

HCID 689016222-(2-Iodophenyl)pyrazineYield 16.2%

Reagents, catalysts & solvents 3

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

Conditions

Temperature
90 °C

Procedure

1-Bromo-2-iodobenzene (0.32 mL, 2.4 mmol), copper(I) iodide (50 mg, 0.26 mmol) and bis(triphenylphosphine)palladium(II) chloride (88 mg, 0.12 mmol) were added to a degassed solution of 2-tributylstannylpyrazine (1.0 g, 2.4 mmol) in tetrahydrofuran (10 mL) and stirred at 90° C. under nitrogen for 22 hours. Diethyl ether was added to the cooled mixture, filtered through ‘Hyflo’ silica and concentrated in vacuo. Purification by flash column chromatography eluting with a 10-100% diethyl ether/isohexane gradient gave a pale yellow oil of 2-(2-iodophenyl)pyrazine (0.11 g, 16%) which contained some 2-(2-bromophenyl)pyrazine. 1H NMR (500 MHz, CDCl3) δ 8.85 (1H, d, J=1.4 Hz), 8.71-8.65 (1H, m), 8.59 (1H, d, J=2.5 Hz), 8.00 (1H, d, J=7.9 Hz), 7.49-7.46 (2H, m), 7.19-7.11 (1H, m); m/z (ES+) 283 [MH+].

Workup

  1. filtrationfiltered through ‘Hyflo’ silica
  2. concentrationconcentrated in vacuo
  3. customPurification by flash column chromatography
  4. washeluting with a 10-100% diethyl ether/isohexane gradient

Sources & evidence

ORD record
ord-e7a75c20525948fb923c53b1cac2338f
Source dataset
uspto-grants-2009_09
Patent number
US07592456B2

Reaction notes

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