反应详情

A solution of 1.74 g (15 mmole) of 2-ketovaleric acid and 1.13 g (10 mmole) of 2,2-dimethylcyclopropanecarboxamide in 20 ml of toluene was refluxed with stirring with collection of H2O in a small Dean-Stark trap. After 20 hrs. the solution was cooled and treated with a gentle stream of N2. Before much of the solvent had evaporated, crystallization was induced by scratching. After standing, the solid was collected on a filter and washed with toluene and some Et2O. Yield of white crystals=0.63 g (30%), mp 154.5°-155.5° (slight prelim. softening). Tlc (4:1 toluene-AcOH) showed only an extremely faint trace of the other isomer. NMR was consistent with the Z-configuration.

1. temperaturethe solution was cooled
2. customBefore much of the solvent had evaporated
3. customcrystallization
4. customthe solid was collected on
5. filtrationa filter
6. washwashed with toluene