反应详情

A solution of 3-chloroquinoxaline-2-carbonyl chloride (3.5 g, 15.45 mmol) in dichloromethane (32.3 mL) was added dropwise to a mixture of methyl 5-aminopyridine-2-carboxylate (2.35 g, 15.45 mmol), pyridine (3.75 mL, 46.35 mmol) and dichloromethane (48.38 mL) at 0° C. The mixture was stirred and allowed to warm up to room temperature overnight. To the reaction, water (40 mL) was added and the product precipitated. The solid was isolated by filtration, washed with water (1×40 mL) and hexanes (2×50 mL) to yield methyl 5-[(3-chloroquinoxaline-2-carbonyl)amino]pyridine-2-carboxylate (4.31 g, 81%) as a cream colored solid. 1H NMR (400 MHz, DMSO-d6) δ 11.61 (s, 1H), 9.00 (d, J=2.5 Hz, 1H), 8.46 (dd, J=8.6, 2.6 Hz, 1H), 8.36-8.26 (m, 1H), 8.24-8.12 (m, 2H), 8.12-7.95 (m, 2H), 3.89 (s, 3H) ppm. ESI-MS m/z calc. 342.05, found 343.4 (M+1)+; Retention time: 1.25 minutes (3 minutes run).

1. additionwas added
2. customthe product precipitated
3. customThe solid was isolated by filtration
4. washwashed with water (1×40 mL) and hexanes (2×50 mL)