Triphenylphosphine → N-(2-(5-cyano-2-(triethylsilyl)-1H-indol-3-yl)ethyl)-5-(2,5-difluorobenzyl)isoxazole-3-carboxamide

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-(2-azidoethyl)-2-(triethylsilyl)-1H-indole-5-carbonitrile (0.400 g; 1.23 mmol) and triphenylphosphine (0.523 g; 2.00 mmol) in methanol (10 mL) was stirred at 70° C. for 2 hours. The reaction mixture was concentrated under reduced pressure and the crude material was dissolved in a mixture of 5-(2,5-difluorobenzyl)isoxazole-3-carboxylic acid intermediate 74 (0.318 g, 1.33 mmol), HATU (0.506 g; 1.33 mmol) and N,N diisopropylethylamine (0.614 mL; 3.33 mmol) in DMF (10 mL), was stirred at room temperature for 72 hours. The reaction mixture was partitioned between ethyl acetate and sodium hydrogen sulphate; the organic layer was washed with sodium carbonate, brine, dried and concentrated under reduced pressure. The crude mixture was purified by flash chromatography on silica (eluent 2 to 60% ethyl acetate in heptane) to yield 0.338 g (48%) of N-(2-(5-cyano-2-(triethylsilyl)-1H-indol-3-yl)ethyl)-5-(2,5-difluorobenzyl)isoxazole-3-carboxamide as a solid.

Provenance & Evidence