反応 #71531

反応方程式

2,5-dibromopyridine

3-bromophenylboronic acid

Na2CO3

EtOH

→

5-bromo-2-(3′-bromophenyl)-pyridine

溶媒

toluene

反応条件

後処理

1. 1
   その他was degassed
2. 2
   温度heated
3. 3
   温度to cool
4. 4
   その他the two phases were separated
5. 5
   抽出The aqueous layer was extracted with ether (3×15 cm3)
6. 6
   洗浄washed with brine (1×40 cm3)
7. 7
   乾燥dried over anhydrous sodium sulfate
8. 8
   その他The solvents were completely removed
9. 9
   その他to leave an orange oil
10. 10
    その他The oil was purified by column chromatography over silica gel
11. 11
    その他to give 2.50 g (45%) of B-1 as a pale yellow solid

実験手順

A mixture of 2,5-dibromopyridine (4.33 g, 17.7 mmol), 3-bromophenylboronic acid (4.70 g, 21.3 mmol), tetrakis(triphenylphosphine) palladium (0) (800 mg, 0.692 mmol), 2 M Na2CO3(aq) (18 cm3), EtOH (18 cm3) and toluene (50 cm3) was degassed and heated at reflux with a bath temperature of 105° C. under argon for 23 h. The reaction was allowed to cool and the two phases were separated. The aqueous layer was extracted with ether (3×15 cm3). The organic layer and the ether extracts were combined, washed with brine (1×40 cm3) and dried over anhydrous sodium sulfate. The solvents were completely removed to leave an orange oil. The oil was purified by column chromatography over silica gel using DCM-light petroleum (0:1 to 1:10) as eluent to give 2.50 g (45%) of B-1 as a pale yellow solid; δH(200 MHz; CDCl3) 7.26-7.42 (1 H, m, ArH), 7.57 (2 H, m, PyH & ArH), 7.88 (2 H, m, PyH & ArH), 8.14 (1 H, m, ArH), and 8.74 (1 H, m, PyH); m/z [CI(NH3)] 312, 314, 316 (MH+).

出典