反应详情

温度

100 °C

A mixture of 2-amino-5-bromopyrazine (0.5 g, 2.79 mmol) and [4-(methylsulfonyl)phenyl]boronic acid (0.57 g, 2.79 mmol) in 1,4-dioxane (10 mL) and MeOH (4 mL) was treated with 2M Na2CO3 (4 mL) and Pd(PPh3)4 (65 mg, 0.06 mmol). The reaction mixture was degassed with N2 and heated at 100° C. for 3 h. Most of 1,4-dioxane and MeOH was removed under reduced pressure. Water was added, and the mixture was extracted with EtOAc (50 mL×4). The combined organic extracts were washed with brine, dried over Na2SO4, filtered, and the filtrate was concentrated to a brown solid, which was triturated with CH2Cl2 to give 0.465 g (67%) of 5-[4-(methylsulfonyl)phenyl]-2-pyrazinamine as a yellow solid. The filtrate was washed with 1 N HCl (25 mL), and the aqueous layer was separated and basified with 4N NaOH. The mixture was extracted with EtOAc (50 mL×2) and the combined organic extracts were washed with brine, dried over Na2SO4, filtered, and the filtrate was concentrated to give additional 0.045 g (7%) of 5-[4-(methylsulfonyl)phenyl]-2-pyrazinamine as a yellow solid. 1H NMR (400 MHz, DMSO-d6): δ 8.63 (s, 1H), 8.15 (d, 2H, J=8.5 Hz), 7.97 (s, 1H), 7.91 (d, 2H, J=8.5 Hz), 6.81 (s, 2H), 3.20 (s, 3H); LRMS (ESI), m/z 250 (M+H).

1. customThe reaction mixture was degassed with N2
2. customMost of 1,4-dioxane and MeOH was removed under reduced pressure
3. additionWater was added
4. extractionthe mixture was extracted with EtOAc (50 mL×4)
5. washThe combined organic extracts were washed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationthe filtrate was concentrated to a brown solid, which
9. customwas triturated with CH2Cl2