Hydrochloric Acid → N-stearyl pyridone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a 2 liter Erlenmeyer 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 colorless mixture was stirred and heated to 120° C. internal temperature for 1 hour, during which time a 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 brown 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 tan precipitate formed instantly and the slurry was vacuum filtered followed by rinsing 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.

Herkunft & Nachweise