2-Oxobutanoic Acid → 2-isovaleramidobut-2-enoic acid

Participants

Reaction Steps

A solution of 1.07 g (10.5 mmole) of 2-ketobutyric acid and 0.71 g (7.0 mmole) of isovaleramide in 15 ml of toluene was stirred under reflux with collection of H2O in a small Dean-Stark trap. After 5 hrs, the solution was cooled, resulting in fairly heavy crystallization. After standing, the solid was collected on a filter and washed with toluene and then with CH2Cl2. Yield of white crystals=0.47 g, mp 172°-174° (slight prelim. softening). The material was recrystallized from diisopropyl ketone. Tlc (4:1 toluene-AcOH) now showed only a faint trace of the other isomer. Yield of white crystals=0.32 g (25%), mp 175° (slight prelim. softening). NMR indicated essentially exclusively Z-isomer.

Provenance & Evidence