Acetic Anhydride → Aurone

Participants

Reaction Conditions

Reaction Steps

The compounds of this invention are prepared as shown in the following reaction scheme: ##STR2## in which R1 and R2 are as defined in formula I. Thus, as shown above, a 3-coumaranone is reacted with an appropriately substituted benzaldehyde and acetic anhydride by heating at a temperature up to about 100° C. for from 1 to 3 hours. The reaction mixture is treated with ice, extracted with a nonreactive organic solvent such as ether and the product from the extract is heated at reflux for about one hour with a mineral acid, such as hydrochloric acid, an alkanol such as methanol or ethanol, and water. Cooling gives the substituted aurone product.

Provenance & Evidence