Reaktion #71530

Reaktionsgleichung

2,4-dibromopyridine

3-bromophenylboronic acid

Na2CO3

EtOH

→

4-bromo-2-(3′-bromophenyl)-pyridine

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas degassed
2. 2
   Temperaturheated
3. 3
   Temperaturto cool
4. 4
   Sonstigethe two phases were separated
5. 5
   ExtraktionThe aqueous layer was extracted with ether (3×13 cm3)
6. 6
   Waschenwashed with brine (1×30 cm3)
7. 7
   Trocknendried over anhydrous sodium sulfate
8. 8
   SonstigeThe solvents were completely removed
9. 9
   Sonstigeto leave a black brown oil
10. 10
    SonstigeThe oil was purified by column chromatography over silica gel
11. 11
    Sonstigeto give 1.03 g (24%) of A-6 as a white solid

Vorschrift

A mixture of 2,4-dibromopyridine (3.30 g, 13.9 mmol), 3-bromophenylboronic acid (3.69 g, 16.7 mmol), tetrakis(triphenylphosphine) palladium (0) (643 mg, 0.557 mmol), 2 M Na2CO3(aq) (12 cm3), EtOH (12 cm3) and toluene (40 cm3) was degassed and then heated at reflux with a bath temperature of 110° C. under argon for 3.5 days. The reaction was allowed to cool and the two phases were separated. The aqueous layer was extracted with ether (3×13 cm3). The organic layer and the ether extracts were combined, washed with brine (1×30 cm3) and dried over anhydrous sodium sulfate. The solvents were completely removed to leave a black brown oil. The oil was purified by column chromatography over silica gel using DCM-light petroleum (0:1 to 1:10) as eluent to give 1.03 g (24%) of A-6 as a white solid; δH(200 MHz; CDCl3) 7.36 (1 H, m, ArH), 7.45 (1 H, m, PyH), 7.58 (1 H, m, ArH), 7.89 (2 H, m, PyH & ArH), 8.16 (1 H, m, ArH), and 8.52 (1 H, m, PyH); m/z [APCI+]311, 314, 316 (MH+).

Quelle