video tutorial Alkaline hydrolysis of methyl salicylate

Name: video tutorial - Alkaline hydrolysis of methyl salicylate
Uploaded: 2025-12-11T09:03:44.243Z
Duration: 14 min 39 s
Description: aspirin tablets, but it uses lots of solvent and it's difficult to get a lot of product....Salicylates are useful compounds and luckily there's another very OTC source of these compounds.

Source material: oil of wintergreen (methyl salicylate), hydrolyzed with sodium hydroxide to form sodium salicylate and methanol; excess NaOH used to drive precipitation of the salt and prevent premature loss of salicylic acid.
Procedure: combine 100 mL methyl salicylate with 200 mL water and 47 g NaOH; heat to reflux for about 2 hours to form the sodium salicylate salt; methanol distills off (approx. 35 mL collected) and is hazardous due to toxicity; maintain good ventilation and use proper glassware seals.
Acid work-up: cool and dilute the post-reaction mixture, then slowly add concentrated HCl (about 100 mL scaled to neutralize NaOH and salicylate); heat briefly to drive reaction and ensure complete conversion to salicylic acid, then cool to precipitate.
Isolation: filter the salicylic acid, wash with cold water, and dry; the product appears as a fluffy white solid and is typically quite water-hydrated, making drying challenging.
Verification: dissolve a sample in hot water and add iron(III) chloride to form an intense blue iron(III) salicylate complex, indicating presence of salicylic acid.
Purification: recrystallization from boiling water can yield purer salicylic acid; use boiling water, cover with plastic wrap to limit evaporation, and allow the saturated solution to crystallize on cooling to form needle-like crystals.
Notes: the process yields a visually interesting product; final crystals are fluffy white; discuss handling hazards with methanol and high-alkaline solutions; the reaction is driven to completion due to salicylate formation, unlike typical ester hydrolysis equilibria.