反应详情

5-chloropyrazine-2-carbonyl chloride (2.13 gram, 12.05 mmol) and dimethylamine HCl salt (1.06 gram, 12.7 mmol) were suspended in dichloromethane (50 mL) with stirring. Triethylamine (5.04 mL, 36.2 mmol) in dichloromethane (25 mL) was added dropwise at 0° C. to the reaction mixture. The combined solution was warmed up to ambient temperature and stirred for 4 hours. The compound was diluted with dichloromethane, washed with 1N HCl, water, brine, dried (Na2SO4), filtered and concentrated. The crude product was purified by column chromatography (silica gel, gradient of 30 to 80% ethyl acetate in heptane) to provide desired 5-chloro-N,N-dimethylpyrazine-2-carboxamide (SM-1: 2.24 g, 85%). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.74 (d, J=1.37 Hz, 1H) 8.53 (d, J=1.37 Hz, 1H) 3.15 (s, 3H) 3.12 (s, 3H)

1. stirringstirred for 4 hours
2. washwashed with 1N HCl, water, brine
3. dry with materialdried (Na2SO4)
4. filtrationfiltered
5. concentrationconcentrated
6. customThe crude product was purified by column chromatography (silica gel, gradient of 30 to 80% ethyl acetate in heptane)