Question

PREPARATION OF BENZOCAINE

1. A student wants to prepare benzocaine by oxidizing p-nitrotoluene to p-nitrobenzoic acid, followed by esterification with ethanol and acid and then reducing the nitro group.

Do you think the student can prepare benzocaine using this prcodure? Explain your answer.

2. Write the full balanced equations for all three reactions that occur when the saturated sodium

bicarbonate solution is added to the cooled reaction mixture.

3. Why it is important to maintain the pH in step # 5? (step 5: Place a magnetic stir bar in the beaker and add 10% aqueous sodium bicarbonate solution drop wise with stirring. Continue the addition till the pH of the solution is around 7.5-8 or until gas evolution ceases. At this point the p-aminobenzoate will precipitate as white solid.)

Answer 1

A Chemistry student can be synthesised  benzocaine by oxidizing p-nitrotoluene to p-nitrobenzoic acid, followed by esterification with ethanol and acid and then reducing the nitro group. Because all three steps are easy and well known steps.