p-Toluenesulfonic acid → 3-fluoro-N-isobutylphthalimide

HRID 1792941Notes

Reaction equation

HRID 1792941 reaction equation
[F: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>[F:1][C:2]1[CH:12]=[CH:11][CH:10]=[C:4]2[C:5]([N:17]([CH2:13][CH:14]([CH3:16])[CH3:15])[C:8](=[O:9])[C:3]=12)=[O:7]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 6558IsobutylamineHCID 695513-Fluorophthalic anhydride

Product 1

HCID 220255003-fluoro-N-isobutylphthalimide

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
140 °C

Procedure

3-Fluoro-N-isobutylphthalimide is prepared as described in Example 2, starting with 3.4 g of 3-fluorophthalic anhydride, 2.0 cm3 of isobutylamine and a catalytic amount of para-toluenesulfonic acid in 20 cm3 of toluene. The reaction mixture is heated at a temperature in the region of 140° C. for 3 hours. After cooling to a temperature in the region of 20° C., the reaction mixture is concentrated to dryness under reduced pressure (2 kPa). The residue is taken up in dichloromethane and washed 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. The residue is dried in a desiccator under reduced pressure (2 kPa) at a temperature in the region of 20° C. 4.0 g of 3-fluoro-N-isobutylphthalimide are thus obtained in the form of an off-white powder. (Rf=0.73, thin layer chromatography on silica gel, eluent: dichloromethane).

Workup

  1. custom3-Fluoro-N-isobutylphthalimide is prepared
  2. temperatureAfter cooling to a temperature in the region of 20° C.
  3. concentrationthe reaction mixture is concentrated to dryness under reduced pressure (2 kPa)
  4. washwashed with saturated aqueous sodium bicarbonate solution
  5. customThe organic phase is separated out after settling
  6. dry with materialdried over magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 40° C
  9. customThe residue is dried in a desiccator under reduced pressure (2 kPa) at a temperature in the region of 20° C

Sources & evidence

ORD record
ord-cbdf2c15a68c4c8bbaa462ea6aa0317e
Source dataset
uspto-grants-2006_07
Patent number
US07078428B2

Reaction notes

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