ethyl 2-[(5-chloro-1-benzofuran-2-yl)methylamino]-2-oxoacetate

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of (5-chloro-1-benzofuran-2-yl)methanamine (420 mg, crude) in dichloromethane (50 ml) was added triethylamine (315 mg, 3.12 mmol). Then ethyl 2-chloro-2-oxoacetate (378 mg, 2.77 mmol) was added dropwise and the contents were stirred for 30 minutes at 0° C. The resulting solution was quenched with water (100 ml) and extracted with dichloromethane (3×70 ml). The organic fractions were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified by silica gel column chromatography eluting with 20% ethyl acetate in petroleum ether to afford ethyl [[(5-chloro-1-benzofuran-2-yl)methyl]carbamoyl]formate as an off-white solid (600 mg). (ES, m/z): [M+H]+ 282.0; 1H NMR (400 MHz, CDCl3): δ 7.52 (s, 2H), 7.38 (d, J=8.4 Hz, 1H), 7.26 (d, J=8.8 Hz, 1H), 6.64 (s, 1H), 4.68 (d, J=4.2 Hz, 2H), 4.39 (q, J=7.2 Hz, 2H), 1.37 (t, J=7.2 Hz, 3H). The resulting solution was quenched with water (100 ml) extracted with dichloromethane (3×70 ml) dried over anhydrous sodium sulfate filtered concentrated under vacuum The residue was purified by silica gel column chromatography eluting with 20% ethyl acetate in petroleum ether