Urea → 5-tert-butylisoindole-1,3-dione

HRID 2073403Notes

Reaction equation

HRID 2073403 reaction equation
[C:1]([C:5]1[CH:6]=[C:7]2[C:12](=O)[O:11][C:9](=[O:10])[C:8]2=[CH:14][CH:15]=1)([CH3:4])([CH3:3])[CH3:2].[NH2:16]C(N)=O>CN(C)C=O>[C:1]([C:5]1[CH:6]=[C:7]2[C:12](=[O:11])[NH:16][C:9](=[O:10])[C:8]2=[CH:14][CH:15]=1)([CH3:4])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 1176UreaHCID 1229304-tert-Butylphthalic anhydride

Product 1

HCID 6047635-tert-butylisoindole-1,3-dioneYield 91.8%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
250 °C

Procedure

Equimolar quantities of 4-t-butylphthalic anhydride (150.33 grams, 0.7361 mol) and urea (44.21 grams) were mixed with a thermometer in a 1 liter round bottom flask. The solids were heated slowly with a Meker burner. At 175° C., the reaction became exothermic and had to be cooled with an air gun. When the exotherm subsided, the temperature was increased to 250° C. and maintained at that temperature for 30 minutes. The flask was then cooled and 300 milliters of dimethylformamide was added, after which the solution was filtered by gravity to remove any solids which should not dissolve. Water (1 liter) was added, resulting in precipitation of 137.34 grams (0.6757 mole) of 4-t-butyl-phthalimide, which exhibited a melting point of 136.5° to 140° C. The identity of the 4-t-butyl-phthalimide product was confirmed by IR spectrum.

Workup

  1. temperatureThe solids were heated slowly with a Meker burner
  2. customAt 175° C.
  3. temperatureto be cooled with an air gun
  4. temperaturemaintained at that temperature for 30 minutes
  5. temperatureThe flask was then cooled
  6. filtrationafter which the solution was filtered by gravity
  7. customto remove any solids which should not
  8. dissolutiondissolve
  9. additionWater (1 liter) was added

Sources & evidence

ORD record
ord-62f57c9aed99490494801b9f7c29e59a
Source dataset
uspto-grants-1990_04
Patent number
US04916470

Reaction notes

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