Pivaloyl chloride → N-(4-Chloropyridin-2-yl)pivalamide

関与物質

反応手順

This compound was prepared as reported by K. S. Gudmundsson et al, Synthetic Communications 1997, 27 (5), 861-870: To a stirred solution of 2-amino-4-chloropyridine (0.723 g, 5.62 mmol) in anhydrous pyridine (2.8 ml) was dropwise added trimethylacetyl chloride (1.02 g, 8.46 mmol). The reaction mixture was stirred at room temperature for 4.5 h under argon, then partitioned between ethyl acetate (70 ml) and water (50 ml). The aqueous layer was extracted with ethyl acetate (2×30 ml), and the combined organics were washed with saturated aqueous NaHCO3 (40 ml), brine (50 ml), dried (Na2SO4), and concentrated in vacuo. The residue was absorbed on silica gel and the free running powder was placed on a 50 g isolute silica column. Elution with 20% ethyl acetate in hexanes and 25% ethyl acetate in hexanes afforded the title compound as a white solid (0.880 g, 74%); 1H-NMR (250 Mz, DMSO-d6) 1.24 (s, 9H, C(CH3)3), 7.25 (dd, J=1.91 Hz, 5.36 Hz, 1H, 5-H), 8.17 (d, J=1.87 Hz, 1H, 3-H), 8.34 (d, J=5.35 Hz, 1H, 6-H), 10.09 (s, 1H, CONH); LC-MS (ESI, m/z) 6.91 min—213, 215 [(M+H)+, Cl isotopic pattern].

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