Preparation
chemical synthesis method for Octadecyl isothiocyanate, using octadecylamine and bis(trichloromethyl) carbonate as raw materials, involves slowly adding a solution of octadecylamine dissolved in an organic solvent to a solution of bis(trichloromethyl) carbonate dissolved in the same organic solvent, while maintaining the reaction system temperature at 0–5°C. After the addition is complete, the mixture is stirred at room temperature for 0.5–5 hours, then heated to 35–150°C and reacted at this temperature for 0.5–10 hours. After the reaction is complete, the reaction solution is post-treated to obtain the Octadecyl isothiocyanate. The reaction equation is as follows: The molar ratio of octadecylamine to bis(trichloromethyl) carbonate is 1:1/3, the solvent is n-hexane, and the amount used is 2 mL/g based on the mass of octadecylamine. The specific steps are as follows: 29.7 g (0.1 mol) of bis(trichloromethyl) carbonate and 70 mL of n-hexane were added to a four-necked flask equipped with a mechanical stirrer, thermometer, constant-pressure dropping funnel, and reflux condenser. Stirring was started, and the mixture was cooled to 0–5 °C. A solution of 80.7 g (0.3 mol) of octadecylamine in 90 mL of n-hexane was added dropwise to the reaction system through the constant-pressure dropping funnel at a rate of approximately 1.5 mL/min. After the addition was complete, the mixture was stirred at room temperature for 0.5 h, then heated to 70 °C and reacted at 70–80 °C for approximately 2.5 h. After the reaction was complete, nitrogen gas was purged to purge hydrogen chloride gas. After recovering the n-hexane by vacuum distillation, 69.4 g of Octadecyl isothiocyanate was distilled off, yielding 78.2%. Gas chromatography determined the product purity to be 98.0%. Nuclear magnetic resonance (Bruke): ¹H NMR (300 MHz, CDCl₃): Δ (ppm) 3.28 (t, J = 6.68 Hz, 2H), 1.58–1.63 (m, 2H), 1.26–1.39 (m, 30H), 0.89 (t, J = 6.32 Hz, 3H); Infrared (AVATAR-370): IRvmax (KBr): 2925, 2854, 2270, 1462, 1356, 721 cm⁻¹.
