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

HRID 229945Notes

Reaction equation

HRID 229945 reaction equation
[CH2:1]([CH:5]([CH2:10][C:11]([OH:13])=[O:12])[CH2:6][C:7]([OH:9])=O)[CH:2]([CH3:4])[CH3:3].C(OC(=O)C)(=O)C>>[CH2:1]([CH:5]1[CH2:6][C:7](=[O:9])[O:13][C:11](=[O:12])[CH2:10]1)[CH:2]([CH3:3])[CH3:4]

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 10976240Isobutylglutaric acid

Product 1

HCID 11480690Dihydro-4-(2-methylpropyl)-2H-pyran-2,6(3H)-dione

Procedure

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.

Workup

  1. customA 1 liter four-necked flask equipped with a mechanical stirrer
  2. temperatureThe reaction mixture was refluxed at 135°-145° C. for 2.5-3 hours
  3. distillationby distilling out the unreacted acetic anhydride at 147°-155° C.
  4. distillationthe distillation
  5. customremoval of traces of unreacted acetic anhydride
  6. temperatureThe residue was cooled to 25°-30° C.

Sources & evidence

ORD record
ord-76539ddc22b64ea0b2f38d23c895579e
Source dataset
uspto-grants-2009_07
Patent number
US07563923B2

Reaction notes

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