Synthesis of Benzocaine

Add 9.10 g of para-aminobenzoic acid and 60 mL of absolute ethanol to a RBF, place the flask in an ice bath and slowly add 9 mL of conc. sulfuric acid with stirring. Reflux for 2h, cool down slowly, start adding 10% sodium hydroxide solution until the pH is neutral, pour the white mixture into 500 mL of cold water and stir. Filter and wash the benzocaine with cold water. Recrystallize in hot ethanol.

Source

The mixture before reflux

The mixture after solvation of the reagents

Addition of the sulfuric acid

Refluxing the solution

The solution after complete reflux

The sodium carbonate solutions

Addition of the sodium carbonate solution

Filtration of the mixture to separate the crude benzocaine

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