Acetic Anhydride → Dihydro-4-(2-methylpropyl)-2H-pyran-2,6(3H)-dione

Participants

Reaction Steps

A 1 liter four-necked flask equipped with a mechanical stirrer, thermometer pocket and condenser, was charged with 3-isobutyl glutaric acid (250 g) and acetic anhydride (62.7 g). The reaction mixture was refluxed at 135°-145° C. for 2.5-3 hours, followed by distilling out the unreacted acetic anhydride at 147°-155° C., and then the distillation was continued under vacuum to ensure removal of traces of unreacted acetic anhydride. The residue was cooled to 25°-30° C. to obtain 220-225 g of 3-isobutylglutaric anhydride.

Provenance & Evidence