Hydrochloric Acid → N-[2-(2,4-dichloro-phenyl)4-methyl-pyridin-3-yl]-acetamide

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Reaction Steps

To a mixture of 2-(2,4-dichloro-phenyl)4-methyl-3-nitro-pyridine (29; 1.15 g, 4.05 mmol), 10 mL of ethanol, 2.5 mL of water, and 0.5 mL of a concentrated HCl solution at 85° C. was added iron powder (1.37 g, 24.6 mmol). The grey suspension was stirred for 1 h, allowed to cool, and filtered through CELITE® 521 and the residual pad was washed well with methanol. The filtrate was concentrated, and the reddish-orange residue was partitioned between 50 mL of ethyl acetate and 50 mL of a saturated aqueous NaHCO3 solution. The organic layer was washed with 50 ML of a saturated aqueous NaCl solution, dried over MgSO4, filtered, and concentrated to a yellow oil. To the oil was added 10 mL of toluene and acetic anhydride (0.41 mL, 4.35 mmol), and the yellow solution was stirred at 100° C. for 23 h then concentrated to a dark yellow residue. Column chromatography (50→66% EtOAc/hexanes) afforded of N-[2-(2,4-dichloro-phenyl)-4-methyl-pyridin-3-yl]-acetamide (30; 0.815 g; 68%) as an off-white solid.

Provenance & Evidence