Ethyl Acetate → N-[6-chloro-5-(4-nitrophenyl)-1-[[2-(trimethylsilyl)ethoxy]methyl]-1H-indazol-3-yl]butanamide

Participants

Reaction Steps

246 mg of 4-bromonitrobenzene, 1.2 g of sodium carbonate in 20 cm3 of water and 365 mg of tetrakis(triphenylphosphine)palladium are added to 2 g of N-[6-chloro-5-(4,4,5,5-tetramethyl[1,3,2]dioxaborolan-2-yl)-1-[[2-(trimethylsilyl)ethoxy]methyl]-1H-indazol-3-yl]butanamide, described previously, in 100 cm3 of dioxane. The medium is then refluxed for 20 hours and the resulting mixture is then allowed to return to room temperature and 100 cm3 of ethyl acetate and 100 cm3 of water are added. The reaction medium is filtered through a sinter funnel packed with Celite and the organic phase is separated out after settling of the phases has taken place, washed with 100 cm3 of water, with 100 cm3 of saturated aqueous sodium chloride solution, dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (2 kPa; 45° C.). The crude product is purified by chromatography under an argon pressure of 50 kPa, on a column of silica gel (particle size 40-60/μm; diameter 4 cm), eluting with a cyclohexane/ethyl acetate mixture (85/15 by volume). The fractions containing the expected product are combined and evaporated under reduced pressure (2 kPa; 50° C.). 690 mg of N-[6-chloro-5-(4-nitrophenyl)-1-[[2-(trimethylsilyl)ethoxy]methyl]-1H-indazol-3-yl]butanamide are obtained in the form of yellow crystals.

Provenance & Evidence