5-Amino-2-chloropyridine → 4-(6-Chloro3-pyridinylamino)-3-ethoxy-cyclobut-3-ene-1,2-dione
反応式
[NH2:1][C:2]1[CH:3]=[CH:4][C:5]([Cl:8])=[N:6][CH:7]=1.[CH2:9]([O:11][C:12]1[C:13](=O)[C:14](=[O:19])[C:15]=1[O:16]CC)[CH3:10]>C(O)C>[Cl:8][C:5]1[N:6]=[CH:7][C:2]([NH:1][C:13]2[C:14](=[O:19])[C:15](=[O:16])[C:12]=2[O:11][CH2:9][CH3:10])=[CH:3][CH:4]=1参加物
4
反応条件
- 温度
- 80 °C
実験手順
5-Amino-2-chloropyridine (2.32 g, 18.0 mmol) in ethanol (50 mL) was added to a solution of 3,4-diethoxy-3-cyclobutene-1,2-dione 3.07 g, 18.0 mmol) in ethanol (200 mL) at 70° C. over a period of 6 hours. The mixture was then heated at 80° C. for an additional 18 hours, filtered, and the solvents removed in vacuo. The crude product was suspended in 10% EtOH/EtOAc (30 mL) and adsorbed onto silica gel (15 g). Purification by flash chromatography on silica gel (eluted with 5% EtOH/EtOAc) provided 1.98 g of the desired product as a pale yellow powder.