反应详情

To 1.2 g. of sodium hydride (57% dispersion in mineral oil) suspended in tetrahydrofuran is added dropwise with stirring a solution of 10 g. of 3,5-dicarbethoxy-1,4-dihydro-2,6-dimethyl-4-(2-trifluoromethylphenyl)pyridine in tetrahydrofuran. The mixture is heated on a steam bath for 15 minutes, then it is cooled and enough dimethylformamide is added to dissolve the solid which has separated. To the resulting solution is added dropwise 3.04 g. of ethyl chloroformate and the reaction mixture is stirred at 25° for 15 minutes then heated on a steam bath for 12 hours. The mixture is filtered and concentrated to give an oil which is dissolved in acetonitrile. The solution is extracted with petroleum ether then concentrated to give an oil which is stirred with petroleum ether. The solid formed is filtered and the filtrate is concentrated in vacuo to give an oil which is chromatographed on an alumina "dry column" with methylene chloride as eluant to give 1,3,5-tricarbethoxy-1,4-dihydro-2,6-dimethyl-4-(2-trifluoromethylphenyl)pyridine, m.p. 56°-58°C.

1. additionis added dropwise
2. temperatureThe mixture is heated on a steam bath for 15 minutes
3. temperatureit is cooled
4. dissolutionto dissolve the solid which
5. customhas separated
6. additionTo the resulting solution is added dropwise 3.04 g
7. stirringof ethyl chloroformate and the reaction mixture is stirred at 25° for 15 minutes
8. temperaturethen heated on a steam bath for 12 hours
9. filtrationThe mixture is filtered
10. concentrationconcentrated
11. customto give an oil which
12. extractionThe solution is extracted with petroleum ether
13. concentrationthen concentrated
14. customto give an oil which
15. customThe solid formed
16. filtrationis filtered
17. concentrationthe filtrate is concentrated in vacuo
18. customto give an oil which
19. customis chromatographed on an alumina "
20. dry with materialdry column" with methylene chloride as eluant