HCID 2752581, compound → Phthalide

HRID 2057509Notes

Reaction equation

HRID 2057509 reaction equation
C([O:4][CH:5]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[C:7](=O)[O:6]1)(=O)C.[H][H]>[Pd].CO>[C:5]1([C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[CH2:7][O:6]1)=[O:4]

Participants

5

Reactant 2

HCID 2752581HCID 2752581, compoundHCID 178418361HCID 178418361, compound2×

Product 1

HCID 6885Phthalide

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Conditions

Temperature
35 °C

Procedure

In the manner described in Example 1, the autoclave is filled with 86.4 g of 3-acetoxyphthalide, 400 ml of methanol and 10 g of palladium-on-charcoal catalyst (Pd content 5 wt%), raised to 10 bars with hydrogen, and slowly heated to 35° C. The consumed hydrogen is first replaced by addition in the range up to 10 bars, and then again in the range up to 20 bars and after the reaction rate has decreased. After 3 hours the pressure remains constant. The catalyst is filtered off and the remaining solution is concentrated at 70° C. and 20 Torr in a rotary thin film evaporator. The residue, still smelling slightly of acetic acid, is fractionally distilled between 99° and 103° C. at 0.5 Torr, and the distillate is recrystallized from water. 54 g (90.05% of the theory) of phthalide of a melting point of 72.5° C. is obtained.

Workup

  1. filtrationThe catalyst is filtered off
  2. concentrationthe remaining solution is concentrated at 70° C.
  3. custom20 Torr in a rotary thin film evaporator
  4. customis fractionally distilled between 99° and 103° C. at 0.5 Torr
  5. customthe distillate is recrystallized from water

Sources & evidence

ORD record
ord-2c07b8923c7740818fc3b1ebb7fc3e99
Source dataset
uspto-grants-1980_07
Patent number
US04211711

Reaction notes

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