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
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+].
Wird geladen…
