反应详情

To a stirred solution of 2-amino-5-chloropyridine (0.645 gm 5.0 mmol) in CH2Cl2 (15 mL) was added Et3N (0.80 mL, 6.0 mL, 1.2 eq) followed by addition of ethyl chlorooxoacetate (0.56 mL, 5.0 mmol, 1.0 eq). The mixture was stirred at rt for 2 h. It was diluted with EtOAc; washed with H2O and brine; dried (Na2SO4); and purified by silica gel chromatography to give pure N-(5-chloro-pyridin-2-yl)-oxalamic acid ethyl ester as a white solid (389 mg, yield: 34%). 1H NMR (400 MHz, methanol-d4) δ 8.16 (d, J=2.4 Hz, 1H), 7.97 (d, J=9.4 Hz, 1H), 7.66 (dd, J=8.9, 2.6 Hz, 1H), 4.19 (q, J=6.6 Hz, 2H), 1.20 (t, J=6.6 Hz, 3H) ppm. MS (ESI) 227.0 (M−H).

1. washwashed with H2O and brine
2. dry with materialdried (Na2SO4)
3. customand purified by silica gel chromatography