反应详情

6-chloro-3-nitropyridin-2-amine (0.910 g, 5.24 mmol) was stirred in 15 ml EtOH. Iodine (1.33 g, 5.24 mmol) was added followed by addition of Ag2SO4 (1.64 g, 5.24 mmol). The reaction was stirred for 18 h and was then diluted with −30 ml of water and was filtered and washed with water. Air-drying afforded 1.09 g of 6-chloro-3-nitro-5-iodopyridin-2-amine. The iodide (1.09 g, 3.64 mmol), phenylboronic acid (0.444 g, 3.64 mmol), Pd(PPh3)4 (0.105 g, 0.091 mmol) and Na2CO3 (1.16 g, 10.9 mmol) were stirred in 4 ml of 3:1 dioxane/water and heated to reflux. After 4 h the reaction was diluted with water and extracted 3× with DCM. The combined organic extracts were dried over Na2SO4, filtered, and concentrated. The residue was triturated with ether, and the resulting solid was filtered and washed with ether. The resulting solid showed pure 6-chloro-3-nitro-5-phenylpyridin-2-amine (4-1). The filtrate was purified by flash column chromatography by dissolving in DCM and eluting with 95:5 DCM/EA. Afforded an additional 240 mg pure 6-chloro-3-nitro-5-phenylpyridin-2-amine (4-1). 1H NMR (CDCl3) δ 8.42 (s, 1H), 7.46-7.42 (m, 5H).

1. filtrationwas filtered
2. washwashed with water
3. customAir-drying