Acetic Anhydride → Aurone

HRID 1283375Notes

Reaction equation

HRID 1283375 reaction equation
[O:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3](=[O:10])[CH2:2]1.C(O[C:15](=O)[CH3:16])(=O)C>>[CH:4]1[CH:5]=[CH:6][C:15](/[CH:16]=[C:2]2/[C:3]([C:4]3[C:9]([O:1]/2)=[CH:8][CH:7]=[CH:6][CH:5]=3)=[O:10])=[CH:2][CH:3]=1

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 23556Coumaranone

Product 1

HCID 6537099Aurone

Conditions

Temperature
100 °C

Procedure

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.

Workup

  1. additionThe reaction mixture is treated with ice
  2. extractionextracted with a nonreactive organic solvent such as ether
  3. temperaturethe product from the extract is heated
  4. temperatureat reflux for about one hour with a mineral acid, such as hydrochloric acid
  5. temperatureCooling

Sources & evidence

ORD record
ord-9d1efaa494c4417a90a2aeaa22adc5de
Source dataset
uspto-grants-1976_08
Patent number
US03975380

Reaction notes

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