反应详情

To a solution of sodium ethoxide (1.3 L) (freshly prepared by addition of sodium metal (7.9 g, 0.35 mol) to ethanol (1.3 L)) at 0° C. was added ethylpropionyl acetate (25 g, 0.17 mol) and the solution was stirred at RT for 1 h. To the above solution was added ethoxymethylene malononitrile (21 g, 0.17 mol) at RT and the reaction mixture was refluxed at 80° C. for 2 h. The reaction mixture was cooled, neutralized to pH=7 by addition of 1.5 N HCl and concentrated under vacuum. The obtained residue was diluted with water (100 mL) and filtered. The solid was washed with water and dried under vacuum at 50° C. to give the crude product (27 g). The crude solid was washed with 5% ethyl acetate in pet. ether which gave pure title compound (22.5 g, 59%).

1. temperaturethe reaction mixture was refluxed at 80° C. for 2 h
2. temperatureThe reaction mixture was cooled
3. concentrationconcentrated under vacuum
4. additionThe obtained residue was diluted with water (100 mL)
5. filtrationfiltered
6. washThe solid was washed with water
7. customdried under vacuum at 50° C.
8. customto give the crude product (27 g)
9. washThe crude solid was washed with 5% ethyl acetate in pet. ether which