反应详情

To a solution of (3-chloro-pyrazin-2-yl)-acetic acid (2.00 g) in N,N-dimethylformamide (“DMF”) (20 ml) was added 1,1′-carbonyldiimidazole (1.88 g) and the mixture stirred for 1 hour. To the reaction mixture was added ethanol (20 ml) and the mixture stirred for 1 hour at ambient temperature. The reaction mixture was concentrated and then purified by chromatography on silica gel (eluent 5-95% ethyl acetate in isohexane) to give (3-chloro-pyrazin-2-yl)-acetic acid ethyl ester (1.93 g). 1H-NMR (400 MHz, CDCl3): 8.50 (s, 1H), 8.30 (s, 1H), 4.20 (q, 2H), 4.00 (s, 2H), 1.30 (t, 3H) ppm.

1. stirringthe mixture stirred for 1 hour at ambient temperature
2. concentrationThe reaction mixture was concentrated
3. custompurified by chromatography on silica gel (eluent 5-95% ethyl acetate in isohexane)