Ethyl isonicotinate → Tert-butyl 4-[2-oxo-2-(4-pyridinyl)ethyl]-2-pyridinylcarbamate

関与物質

反応条件

反応手順

Tert-butyl 4-methyl-2-pyridinylcarbamate (Ihle, N. C.; Krause, A. E.; J. Org. Chem., 1996, 61(14):4810-4811; 10 g, 48.0 mmol) was dissolved in 100 mL THF and cooled to −78° C. under argon and was treated with n-butyllithium (2.5-M in hexanes, 48.0 mL, 120 mmol) such that the internal temperature did not exceed −50° C. The reaction was warmed to 20° C. for 20 min. then was recooled to −78° C. and ethyl isonicotinate (10.79 mL, 72.0 mmol) was added neat and the reaction again was warmed to 20° C. and stirred 45 minutes. The reaction was quenched with sat. NaHCO3 and extracted with ethyl acetate. The organics were dried over Na2SO4, filtered and concentrated under reduced pressure to give a red-orange oil which was purified by silica gel chromatography, eluting from 50% ethyl acetate in hexanes to 100% ethyl acetate to afford 7.56 g (50%) of the titled compound as a yellow oil.

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