反应详情

A mixture of 3-(6-chloro-pyrazin-2-yloxymethyl)-benzonitrile I-3a (3.53 g, 14.4 mmol) and piperazine (12.4 g, 143.70 mmol) in ethanol (144 mL) was stirred under reflux for 48 h. The reaction mixture was concentrated to dryness and the residue was dissolved in ethyl acetate (300 mL). The ethyl acetate solution was washed with H2O (4×125 mL), brine (125 mL), dried (Na2SO4), filtered, and concentrated to dryness. The crude material was chromatographed over Silica Gel (40 g) using 5% methanol/methylene chloride with 1% NH4OH as the eluant to give 3.03 g of the desired product (I-3b) as a white solid.

1. temperatureunder reflux for 48 h
2. concentrationThe reaction mixture was concentrated to dryness
3. dissolutionthe residue was dissolved in ethyl acetate (300 mL)
4. washThe ethyl acetate solution was washed with H2O (4×125 mL), brine (125 mL)
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated to dryness
8. customThe crude material was chromatographed over Silica Gel (40 g)