反应 #3595494
相关文献 (1)
openreactiondata ↗doi:10.6084/m9.figshare.5104873.v1; patent:US06352994B2
反应条件: temp:-30.01; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: N,N-Carbonylimidazole (14.86 g) was added to a slurry of pyrazine-2-carboxylic acid in dry dimethylformamide (100 cm3). After stirring for one hour 4-methoxyphenylacetic acid t-butyl ester (10.8 g) was added. The reaction mixture was cooled to −30° C. then sodium hydride (4.62 g) was added. The reaction mixture was stirred at −30° C. for 1 h then allowed to warm to room temperature overnight. The reaction miLture was poured into water and acidified to pH 8 with acetic acid. The solution was extracted with ether (3×250 cm3). The ether extracts were combined, washed with brine, dried over magnesium sulphate filtered and evaporated under reduced pressure to give a solid. The solid was purified by chromatography using ethyl acetate/hexane (1:1) as eluant. The appropriate fractions were combined and evaporated under reduced pressure to give 2-(4-methoxyphenyl)-3-oxo-3-pyrazine-2-yl propionic acid t-butyl ester as a solid (9.8 g 61%) δH (250 MHz; CDCl3) 1.39 (9 H, s, C(CH3)3), 3.70 (3 H, s, OCH3), 5.87(1 H, s, tBuO2CCH), 6.90 (2H, d, J 9 Hz, methoxyphenyl H-2) 7.32 (2H, d, J 9 Hz, methoxyphenyl H-3) 8.66 (1H, dd pyrazine H—) 8.74 (1H, d pyrazine H—) 9.25 (1H, d pyrazine H—) was added to warm to room temperature overnight The solution was extracted with ether (3×250 cm3) washed with brine dried over magnesium sulphate filtered evaporated under reduced pressure to give a solid The solid was purified by chromatography evaporated under reduced pressure
来源 ID: ord-a83e11cc81f0475caab9c8b8000d73c0