Hydrochloric Acid → N-stearyl pyridone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a 2 liter flask equipped with magnetic stir bar and temperature thermostat was charged octadecylamine (stearylamine, 18.9 grams, 0.07 mol; obtained from Sigma-Aldrich Co., Milwaukee, Wis.) followed with ethyl cyanoacetate (7.9 grams, 0.07 mol, density 1.06 grams per milliliter; obtained from Spectrum Chemicals, New Brunswick, N.J.). The resulting mixture was stirred and heated to 120° C. internal temperature for 1 hour, during which time a liquid byproduct was distilled away. To the hot reaction mixture was then sequentially added ethyl acetoacetate (10.08 grams, 0.0775 mol, density 1.02 grams per milliliter; obtained from Lonza Group, Germany), piperidine (11.0 grams, 0.13 mol, density 0.861 grams per milliliter; obtained from Sigma-Aldrich Co.), and a solvent mixture (60 milliliters) containing 5 parts by weight toluene and 1 part by weight 1,2-dimethoxyethane. The reaction proceeded with stirring at 120° C. for another 24 hours. The solvents were then distilled off in vacuo, and the remaining viscous solution was carefully poured into a stirring solution of methanol (80 milliliters), deionized water (20 milliliters), and concentrated hydrochloric acid (16 milliliters, 2.5 mol). A solid precipitate formed instantly and the slurry was vacuum filtered followed by rinsing of the solid cake with 2×50 milliliter portions of 80 percent aqueous methanol. The cake thus obtained was air-dried for 24 hours to afford 24.5 grams (0.061 mol, 87 percent yield) of N-stearyl pyridone product as light tan powder.

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