The structure of procaine, whose hydrochloride salt is the local anesthetic known as Novocain, is shown below. At physiological pH,

Question

The structure of procaine, whose hydrochloride salt is the local anesthetic known as Novocain, is shown below.  At physiological pH,

Quizplus · Accepted Answer

At physiological pH (around 7.4), only the secondary amine nitrogen (nitrogen 2) will be protonated, forming a positively charged ammonium ion. The primary amine nitrogen (nitrogen 1) will remain unprotonated. This is because secondary amines have a higher pKa (around 10.8 for procaine) than primary amines (around 9.8 for procaine), meaning they require a higher pH to be protonated.

The Structure of Procaine, Whose Hydrochloride Salt Is the Local