反应详情

A solution of 3-chloroquinoxaline-2-carbonyl chloride (3.14 g, 13.83 mmol) in dichloromethane (30.19 mL) was added dropwise to a mixture of methyl 4-aminopyridine-2-carboxylate (2.10 g, 13.83 mmol), pyridine (3.36 mL, 41.49 mmol) and dichloromethane (43.49 mL) at 0° C. The mixture was stirred and allowed to warm up to room temperature for 2 hrs. To the reaction, water (100 mL) was added and a precipitate formed. The solid was isolated by filtration, washed with water (1×40 mL) and hexanes (2×50 mL), then with 10 ml EtOAc and 10 ml dichloromethane and dried to yield methyl 4-[(3-chloroquinoxaline-2-carbonyl)amino]pyridine-2-carboxylate (2.64 g, 55%) as a blue-colored solid (1.54 g). ESI-MS m/z calc. 342.05, found 343.2 (M+1)+; Retention time: 0.95 minutes (3 minutes run). 1H NMR (400 MHz, DMSO-d6) δ 11.63 (s, 1H), 8.70 (d, J=5.4 Hz, 1H), 8.51 (d, J=2.1 Hz, 1H), 8.34-8.27 (m, 1H), 8.24-8.16 (m, 1H), 8.13-8.00 (m, 2H), 7.94 (dd, J=5.4, 2.2 Hz, 1H), 3.91 (s, 3H) ppm.

1. additionwas added
2. customa precipitate formed
3. customThe solid was isolated by filtration
4. washwashed with water (1×40 mL) and hexanes (2×50 mL)
5. dry with materialwith 10 ml EtOAc and 10 ml dichloromethane and dried