Acetic Anhydride → Aurone

HRID 2082999Notes

Reaction equation

HRID 2082999 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

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.

Workup

  1. customThe compounds of this invention are prepared
  2. customas shown in the following reaction scheme
  3. additionThe reaction mixture is treated with ice
  4. extractionextracted with a nonreactive organic solvent such as ether
  5. temperaturethe product from the extract is heated
  6. temperatureat reflux for about one hour with a mineral acid, such as hydrochloric acid
  7. temperatureCooling

Sources & evidence

ORD record
ord-2f571148c8404e2085cbc77c11b8835e
Source dataset
uspto-grants-1978_04
Patent number
US04083952

Reaction notes

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