2,4-Dimethyl-6-tetradecylpyrylium hexafluorophosphate (10, n=13, 1.5 g, 3.33 mmol) was dissolved in 15 mL chloroform and treated with 0.71 g (3.33 mmol) of tetradecylamine (11, m=13). Triethylamine (0.5 mL) was then added to the brown-yellow solution, which was subsequently refluxed for 5 minutes, treated with 1 mL of acetic acid and refluxed for another hour. The homogenous mixture was treated with 0.2 mL of concentrated aqueous ammonia, refluxed for 5 min., cooled and extracted with 10 mL of water to solve the precipitated inorganic salts. After separation, the chloroform layer was dried on sodium sulfate and evaporated to dryness to yield 2.00 g of crude product. This product was purified by means of flash chromatography (Silica gel 60) using a 20/80 methanol/chloroform (v/v) mobile phase to yield 0.56 g (22%) of pure product, which was recrystallized from ethanol to yield 0.54 g of crystalline compound (12, m=n=13).
