反应详情

To a 25 mL round bottom flask is added 1-bromo-4-nitrobenzene (404 mg, 2.0 mmol), 4-pyridinylboronic acid (248 mg, 2.0 mmol), Na2CO3 (424 mg, 4.0 mmol) and Pd(PPh3)4 (100 mg, 0.087 mmol), DME (10 mL) and H2O (3 mL). The mixture is degassed and heated at reflux for 14 h. TLC is used to establish the completion of starting bromide, the mixture is allowed to cool to room temperature. EtOAc is added, and the EtOAc layer is washed with H2O (15 mL) and brine (10 mL) and dried over MgSO4. After removal of EtOAc, the resulting residue is subjected to flash chromatography with CH2Cl2/EtOAc (3:1) as eluent to provide the coupling product 4-(4-nitro-phenyl)-pyridine (288 mg, 72%). 1H NMR (400 MHz, CDCl3) ∂ 8.75 (2H, dd, J=6.0 and 2.8 Hz), 8.36 (2H, dd, J=9.6 and 3.2 Hz), 7.80 (2H, dd, J=8.8 and 2.4 Hz), 7.54 (2H, dd, J=5.6 and 2.0 Hz).

1. customThe mixture is degassed
2. temperatureheated
3. temperatureat reflux for 14 h
4. additionEtOAc is added
5. washthe EtOAc layer is washed with H2O (15 mL) and brine (10 mL)
6. dry with materialdried over MgSO4
7. customAfter removal of EtOAc