video tutorial Preparation of crude benzyl cyanide from benzyl chloride

Name: video tutorial - Preparation of crude benzyl cyanide from benzyl chloride
Uploaded: 2025-12-11T09:03:44.222Z
Duration: 7 min 19 s
Description: In this video we prepare benzyl cyanide using the cold netrile synthesis you'll...Check out our other video for details of how we, do this by heating potassium, ferrocyanide

Objective: synthesize benzyl cyanide via cold nitrile synthesis by nucleophilic attack of cyanide on benzyl chloride.
Reagents and preparation: prepare an aqueous alkali cyanide solution (NaCN or KCN); example uses a ~140 mL solution containing ~30 g mixed cyanide from a melt of potassium ferrocyanide and sodium metal.
Setup and safety: use a 500 mL flask with stirring; attach an addition funnel near the atmosphere to vent fumes; cyanide solutions are highly toxic and must be disposed of safely; benzyl chloride is hazardous (eye irritation, absorption through skin).
Procedure: add benzyl chloride (40 g) to the addition funnel; add 40 mL absolute ethanol to the benzyl chloride in the funnel; heat the flask to ~50 °C and slowly add the benzyl chloride/ethanol mixture dropwise with stirring (≈30 min); after addition, reflux the mixture for about 3 hours, observing color change to yellow/orange; continue refluxing and then cool.
Workup: distill off ethanol to ~35 mL; pour the reaction mixture into a separating funnel and allow layers to separate; the bottom aqueous layer contains cyanide and must be disposed of safely; treat the product with slowly added hot 20 mL conc H2SO4 in 40 mL water (two-step acid wash) to remove odors; neutralize with 40 mL saturated NaHCO3 and wash with 40 mL saturated NaCl; separate and collect.
Yield and notes: crude product yield is 32 g (≈86% based on starting benzyl chloride), still dark with impurities; purification by vacuum distillation is recommended to prevent decomposition; product can be used for further experiments.