反应详情

To a solution of 6-methoxy-2-methylquinolin-8-amine 2a (0.19 g, 1.0 mmol) in pyridine (5 ml) was added 4-methyl-2-nitrobenzenesulfonyl chloride (0.24 g, 1.0 mmol). The mixture was stirred at room temperature overnight and precipitated with H2O. The crude product was filtered and recrystallized from EtOH to afford nitrobenzenesulfonamide (0.31 g, 79%) as red crystal. 1H NMR (300 MHz, CDCl3) δ 10.1 (br, 1H); 8.04 (d, 1H), 7.86 (d, 1H), 7.62 (m, 2H), 7.39 (d, 1H), 7.24 (d, 1H), 6.73 (s, 1H), 3.88 (s, 3H), 2.66 (s, 3H), 2.41 (s, 3H); ESI-MS (M++1): 388.0. To a suspension of above nitro compound (0.20 g, 0.56 mmol) in EtOH (5 ml) was added SnCl2 (0.32 g, 1.7 mmol) slowly. The mixture was refluxed for 2 h. After removal of EtOH, the residue was treated with 1M NaOH. The aqueous solution was extracted with CH2Cl2. The combined organic phases were washed by brine, dried over Na2SO4, and concentrated to yield 9a (0.18 g, 92%) as white solid. 1H NMR (300 MHz, CDCl3) δ 9.42 (br, 1H); 7.83 (d, 1H), 7.65 (d, 1H), 7.30 (s, 1H), 7.23 (d, 1H), 6.64 (s, 1H), 6.48 (d, 1H), 6.42 (s, 1H), 3.80 (s, 3H), 2.61 (s, 3H), 2.17 (s, 3H); ESI-MS (M++1): 358.1.

1. customprecipitated with H2O
2. filtrationThe crude product was filtered
3. customrecrystallized from EtOH