Water → 4,7-Difluoro-3-hydroxy-2-isobutyl-2,3-dihydroisoindol-1-one

Participants

Reaction Conditions

Reaction Steps

4,7-Difluoro-3-hydroxy-2-isobutyl-2,3-dihydroisoindol-1-one is prepared as described in Example 1, starting with 6.41 g of 3,6-difluoro-N-isobutylphthalimide in 70 cm3 of methanol and 1.44 g of potassium borohydride. The reaction mixture is stirred at a temperature in the region of 20° C. for 3 hours and is then cooled to a temperature in the region of 0° C. and 45 cm3 of distilled water are added dropwise. The methanol is then partially evaporated off under reduced pressure (2 kPa) at a temperature in the region of 30° C., followed by addition of 80 cm3 of dichloromethane. After separation of the phases by settling, the aqueous phase is extracted twice with 80 cm3 of dichloromethane. The organic extracts are combined, dried over magnesium sulfate, filtered and then concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 30° C. The residue is dried in a desiccator under reduced pressure (2 kPa) at a temperature in the region of 20° C. 5.68 g of 4,7-difluoro-3-hydroxy-2-isobutyl-2,3-dihydroisoindol-1-one are thus obtained in the form of a yellow solid melting at 129.5° C. (Rf=0.48, thin layer chromatography on silica gel, eluent: cyclohexane/ethyl acetate (50/50 by volume)).

Provenance & Evidence