Q. 14.81 - An Introduction to General, Organic, and Biological Chemistry

Question

Novocain, a local anesthetic, is the ammonium salt of procaine. (14.5)

1. Draw the condensed structural formula for the ammonium salt (procaine hydrochloride) formed when procaine reacts with $\mathrm{HCl}$. (Hint: The tertiary amine reacts with HCl.)
2. Why is procaine hydrochloride used rather than procaine?

Step-by-Step Solution

Answer

Part (a):

• The condensed structural formula for the ammonium salt (procaine hydrochloride) formed when procaine reacts with $HCl$ is
  

 Part (b):

• Procaine is less commonly used because it is less soluble in body fluids than procaine hydrochloride (novocaine).

Part (a) Step 1: Given Information

We need to find the condensed structural formula for the ammonium salt when procaine reacts with $HCl$.

• Novocain, a local anesthetic, is the ammonium salt of procaine 
• The Structure of procaine is

Part(a) Step 2: Explanation

Condensed structural formula for the ammonium salt (procaine hydrochloride) formed when procaine reacts with $HCl$

• When procaine reacts with  $HCl$, an amine salt of procaine hydrochloride is formed.
• The structure of the amine salt of procaine hydrochloride is

Part (b) Step 3: Given Information

Frequent use of procaine hydrochloride  rather than procaine 

• Procaine is a local anesthetic and falls into the amino acid group. 
• Procaine hydrochloride,  also known as novocaine, is formed when  procaine reacts with $HCl$ 
• Procaine is less commonly used because it is less soluble in body fluids than procaine hydrochloride (novocaine).