Tributylphosphine → ethyl 7-[(2,2-difluoroethyl)(pyridin-2-ylsulfonyl)amino]-5-(2-methoxyethoxy)-1H-indole-2-carboxylate

Beteiligte Stoffe

Reaktionsschritte

To a mixture of ethyl 5-(2-methoxyethoxy)-7-[(pyridin-2-ylsulfonyl)amino]-1H-indole-2-carboxylate (500 mg), 2,2-difluoroethanol (0.09 mL), tributylphosphine (0.59 mL) and toluene (30 mL) was added 1,1′-(azodicarbonyl)dipiperidine (600 mg), and the mixture was stirred at room temperature overnight. The insoluble substance was filtered off, and the filtrate was diluted with ethyl acetate and 1N aqueous hydrochloric acid solution. The organic layer was washed with aqueous sodium bicarbonate solution and saturated brine, dried over anhydrous magnesium sulfate, and filtered, and the filtrate was concentrated under reduced pressure. The residue was subjected to basic silica gel column chromatography to give the title compound (211 mg, yield 37%) as a colorless amorphous solid from a fraction eluted with ethyl acetate-hexane (1:4, volume ratio).

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