video tutorial Synthesis of benzocaine

Name: video tutorial - Synthesis of benzocaine
Uploaded: 2025-12-11T09:03:43.821Z
Duration: 14 min 45 s
Description: In this video we're going to do a few more reactions with this and transform it into something very interesting....In a video we did recently we checked out a few different ways to do this reduction

Starting from pyronitrobenzoic acid, convert it to its ethyl ester via acid-catalyzed esterification with absolute ethanol and sulfuric acid, refluxing for about 3 hours; after workup and cooling, isolate a crude ethyl nitrobenzoate ester (around 5.9 g dried, with some starting material likely present).
Reduce the nitro group to an arylamine using the sodium diphenate method: prepare sodium diphenate from sodium bisulfite, water, and zinc; adjust the solution to alkaline (pH ~10) with sodium carbonate; dissolve 4 g of the ethyl ester in ethanol (20 mL) and add to the alkaline diphenate solution; heat nearly to boiling for about 1.5 hours with ethanol allowed to boil away.
Work up the reaction by extracting with dichloromethane, basifying the aqueous layer to promote free-base amine formation, and re-extracting with DCM; convert the amine to its hydrochloride salt with dilute HCl to precipitate the final product.
Isolate benzocaine (ethyl 4-aminobenzoate) as a solid (1.1 g, about 32% yield from the starting nitrobenzoic acid); note that some starting material may remain and the yield reflects an experimental procedure.
Additional notes: a two-phase separation occurred during workup, and the procedure claims this is a first-of-its-kind YouTube synthesis for this exact compound using this method; the product is described as having a familiar anesthetic property.