Toluene → methyl 2-{3-cyano-4-[1-(triisopropylsilyl)-1H-pyrrol-3-yl]phenyl}isonicotinate

関与物質

反応条件

反応手順

58 mg of tetrakis(triphenylphosphine)palladium and 208 mg of potassium carbonate were added to a toluene (10 ml) solution of 386 mg of methyl 2-(3-cyano-4-{[(trifluoromethyl)sulfonyl]oxy}phenyl)isonicotinate and 534 mg of 1-(triisopropylsilyl)pyrrole-3-boronic acid, then this was irradiated with microwaves and heated at 130° C. in a nitrogen atmosphere for 1 hour. Water was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was washed with brine, dried and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=95:5 to 70:30) to obtain 24 mg of methyl 2-{3-cyano-4-[1-(triisopropylsilyl)-1H-pyrrol-3-yl]phenyl}isonicotinate. (2) 24 mg of this compound was dissolved in 1 ml of THF, and 63 μL of 1 M tetrabutylammonium fluoride/THF solution was added thereto, followed by stirring at room temperature for 15 hours. The reaction mixture was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (hexane:ethyl acetate=90:10 to 70:30) to obtain 6 mg of methyl 2-[3-cyano-4-(1H-pyrrol-3-yl)phenyl]isonicotinate. (3) 6 mg of this compound was dissolved in a mixture of 0.5 ml of methanol and 0.5 ml of THF, and 22 μl of aqueous 1 M sodium hydroxide solution was added, followed by heating at 60° C. for 2 hours. The reaction liquid was cooled, and the solvent was removed under reduced pressure. Water was added to the residue, followed by neutralization with 1 M hydrochloric acid. The precipitated crystal was collected by filtration and washed with a mixture of ethanol and water to obtain 1.5 mg of 2-[3-cyano-4-(1H-pyrrol-3-yl)phenyl]isonicotinic acid.

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