p-Toluenesulfonic acid → N-isobutyl-3-methylphthalimide

HRID 733260Notes

Reaction equation

HRID 733260 reaction equation
[CH3:1][C:2]1[CH:12]=[CH:11][CH:10]=[C:4]2[C:5]([O:7][C:8](=[O:9])[C:3]=12)=O.[CH2:13]([NH2:17])[CH:14]([CH3:16])[CH3:15].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH2:13]([N:17]1[C:8](=[O:9])[C:3]2=[C:2]([CH3:1])[CH:12]=[CH:11][CH:10]=[C:4]2[C:5]1=[O:7])[CH:14]([CH3:16])[CH3:15]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 6558IsobutylamineHCID 985004-Methyl-1,3-isobenzofurandione

Product 1

HCID 22025457N-isobutyl-3-methylphthalimide

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
140 °C

Procedure

N-Isobutyl-3-methylphthalimide is prepared as described in Example 2, starting with 5.0 g of 3-methylphthalic anhydride, 3.0 cm3 of isobutylamine and a catalytic amount of para-toluenesulfonic acid in 50 cm3 of toluene. The reaction mixture is heated at a temperature in the region of 140° C. for 2.5 hours and then stirred at a temperature in the region of 20° C. for 16 hours. The reaction mixture is concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 40° C. The residue is taken up in dichloromethane and washed twice with saturated aqueous sodium bicarbonate solution. The organic phase is separated out after settling has taken place, dried over magnesium sulfate, filtered and then concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 40° C. 6.0 g of N-isobutyl-3-methylphthalimide are thus obtained in the form of a caramel-colored oil, Rf=0.76 (thin layer chromatography on silica gel, eluent: dichloromethane).

Workup

  1. customN-Isobutyl-3-methylphthalimide is prepared
  2. concentrationThe reaction mixture is concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 40° C
  3. washwashed twice with saturated aqueous sodium bicarbonate solution
  4. customThe organic phase is separated out after settling
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 40° C

Sources & evidence

ORD record
ord-952dde3d152447d9bb281d8fcc8ee311
Source dataset
uspto-grants-2009_09
Patent number
US07589117B2

Reaction notes

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