Ethyl Acetate → N-[6-(3,5-difluorophenyl)-1H-indazol-3-yl]butanamide

Participants

Reaction Conditions

Reaction Steps

14 cm3 of tetrabutylammonium fluoride as a 1M solution in tetrahydrofuran are added to 1.1 g of N-[6-(3,5-difluorophenyl)-1-[[2-(trimethylsilyl)ethoxy]methyl]-1H-indazol-3-yl]butanamide, described previously, in 30 cm3 of tetrahydrofuran. The reaction medium is heated at about 66° C. for 18 hours. The heating is then stopped and 100 cm3 of ethyl acetate are added. This mixture is washed with 2×50 cm3 of saturated aqueous sodium hydrogen carbonate solution and then with 50 cm3 of saturated aqueous sodium chloride solution. The organic phase is dried over magnesium sulphate, filtered through a sinter funnel and evaporated under reduced pressure (2 kPa; 50° C.). The residue is purified by chromatography under an argon pressure of 50 kPa, on a column of silica gel (particle size 40-60 μm; diameter 3.5 cm), eluting with cyclohexane/ethyl acetate (60/40 by volume) and collecting 35 cm3 fractions. The fractions containing the expected product are combined and evaporated under reduced pressure (2 kPa; 50° C.). The residue is taken up in 2×5 cm3 of diisopropyl ether. This mixture is filtered through a sinter funnel and dried under reduced pressure (90 Pa; 50° C.) to give 340 mg of N-[6-(3,5-difluorophenyl)-1H-indazol-3-yl]butanamide in the form of a white solid melting at 260° C.

Provenance & Evidence