video tutorial Trying out a preparation of phenylacetic acid

Name: video tutorial - Trying out a preparation of phenylacetic acid
Uploaded: 2025-12-11T09:03:44.328Z
Duration: 14 min 59 s
Description: video, but this time we're going to try a different procedure to see if we can get a...We've prepared this in the previous video from benzoyl alcohol, so check it out at the

Two-step synthesis: benzoyl chloride reacts with an alkali cyanide salt (sodium/potassium cyanide) in acetone/ethanol with sodium iodide as a catalyst to give benzoyl cyanide via nucleophilic substitution, aided by a benzoyl iodide intermediate.
First step: conduct a ~3-hour reflux with stirring, then isolate benzoyl cyanide by distillation (pale liquid with a characteristic odor).
Second step: hydrolyze the nitrile to phenylacetic acid using 50% sulfuric acid under reflux for about 1 hour; observe color changes indicating reaction progress.
Workup: basify with sodium hydroxide to form sodium phenylacetate, extract with dichloromethane (DCM), dry, and evaporate to yield phenylacetic acid as an off-white solid with a strong honey-like aroma; final yield around 0.5 g in this run.
Overall outcome: the first step produced only a small amount of phenylacetonitrile, leading to a low yield of phenylacetic acid; the method is less effective than the classic benzyl chloride + sodium cyanide route in water/ethanol, which can give reasonable yields after hydrolysis; alternatives like producing mandelic acid and reducing it were also discussed.
Safety note: alkali cyanides are highly toxic; handle with extreme care; cyanide gas can be generated under some conditions; ensure proper safety precautions.