Cocain Synthesis Lab Report

In this lab, a sulfuric acid catalyzed Fischer Esterification reaction was conducted between p-aminobenzoic acid and ethanol in order to produce benzocaine. Once the reactants were done being heated under reflux, the precipitate was collected via vacuum filtration. This crude product weighed 1.35g and was then subject to another heating session with additional H2O while being stirred constantly. Methanol was then added to dissolve the solid and the product was then cooled to below room temperature. The pure product weighed 1.22g, giving a percent yield of 90.4%, and melting temperature as well as IR spectra and 1H-NMR were obtained.

Scheme 1: Fischer Esterification reaction between benzaldehyde and ethanol to produce benzocaine. INTRODUCTION:

The practice of chewing the leaves from the “Coco bush” to produce mild stimulant effects had been observed in American Indian tribes surrounding the Andes mountains for years before the substance responsible for these symptoms was isolated from the Erythroxylon coca leaves.2 Cocaine was the first local anesthetic derived from this plant and it wasn’t until 1900 that German chemist Eduard Ritsert synthesized benzocaine as a non-addictive substitute to its high-risk-for-abuse counterpart.1 For a long time, however, it was not fully understood how this family of compounds interacted with the body. After cocaine’s initial discovery, it was prescribed for numerous applications from a common toothache to fighting depression.4 In recent years, the effects of cocaine’s influence as a local anesthetic are

The mixture was stirred until all of the solid was completely dissolved. 2 mL of concentrated sulfuric acid were added dropwise before a condenser was attached and the apparatus was equipped for heating under reflux. The solution was then heated gently under reflux for 30 minutes. Since no solid was present after the first 30 minutes and the mixture was homogenous, it continued to be heated under reflux for an additional 30 minutes. After this period of time, the mixture was set aside and allowed to cool to room temperature before being poured into a beaker containing 30 mL of water. Next, the pH of the mixture was raised to 8 by slowly adding 10% aqueous sodium carbonate with stirring. The pH was tested using standard pH paper. The crude benzocaine product was then collected via vacuum filtration and then rinsed with 3 washes of cold diluted water. After dry, the crude product was weighed (1.35g) and transferred to a 50 mL Erlenmeyer flask with a stirbar and 20 mL of water. The mixture was then stirred while being heated to 60°C and then just enough methanol was added in order to dissolve the solid. Once all solid had dissolved, it was allowed to cool to room temperature before being added to an ice bath for 10-15 minutes to complete the crystallization. Once again, the product was vacuum filtered to obtain the crystal final pure