Trimethylsilyl iodide → N-(5,6-bis(4-hydroxyphenyl)-1H-indazol-3-yl)butyramide

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Reaction Steps

10 cm3 of trimethylsilyl iodide are added to 700 mg of N-[5,6-bis[4-(phenylmethoxy)phenyl]-1H-indazol-3-yl]butanamide, prepared in Example 97, and the mixture is refluxed for 18 hours. 30 cm3 of methanol are added and the reaction medium is refluxed for 15 minutes and is then concentrated to dryness under reduced pressure (2 kPa; 50° C.). The residue is taken up in 75 cm3 of ethyl acetate and the organic phase is washed with 2×75 cm3 of 10% sodium thiosulphate solution and then with 75 cm3 of saturated sodium chloride solution. The organic phase is separated out after settling of the phases has taken place, dried over magnesium sulphate, filtered and then concentrated to dryness under reduced pressure (2 kPa; 50° C.) to give 900 mg of crude product, which is purified by chromatography under an argon pressure of 50 kPa, on a column of silica gel (particle size 40-60 μm; diameter 3 cm), eluting with a cyclohexane/ethyl acetate mixture (60/40 by volume). The fractions containing the expected product are combined and evaporated under reduced pressure (2 kPa; 50° C.) and the residue is taken up in 20 cm3 of diisopropyl ether, filtered off, washed with 3 cm3 of ethyl acetate, then with 2×10 cm3 of diisopropyl ether and dried (90 Pa; 45° C.) to give 220 mg of N-[5,6-bis(4-hydroxyphenyl)-1H-indazol-3-yl]butanamide in the form of a white powder melting at 180° C.

Provenance & Evidence