Risocaine is the common name for propyl 4aminobenzoate a molecule that acts as a local anesthetic

It is a


Risocaine is the common name for propyl 4-aminobenzoate, a molecule that acts as a local anesthetic. It is a

solid compound that has a literature meing point of 75 oC.

Scenario: You are working in a pharmaceutical laboratory and you are preparing propyl 4-aminobenzoate for use in an over-the-counter local anesthetic gel that is commonly used for tooth and gum pain.

You run the following reaction: A mixture of 4-aminobenzoic acid (1.0 equivalent), propanol (1.5 equivalents) and H2SO4 (0.35 equivalents) is refluxed for 30 minutes. After cooling and performing a basic aqueous work-up you isolate a white solid that has an experimental meing point of 187 oC.

The meing point analysis indicates that the compound isolated from this reaction is not the target compound. What is the structure of the compound that was isolated from the reaction? Explain (with the use of a mechanism) why the reaction did not work, and what procedural modification you can do to enable the synthesis of the target compound.