Organic Chemistry

Analgesics are neurological active drugs that reduce or abolish pain without causing impairment of consciousness.

• Morphine, Heroin (diacetylmorphine), and Codeine are narcotic analgesics (opiates) prescribed for severe pain relief.
• Ranitidine (Zantac) is an antacid and antihistamine ($H_2$-receptor antagonist) that prevents the interaction of histamine with receptors in the stomach wall, thereby decreasing hydrochloric acid secretion.

Aspartame is the methyl ester of a dipeptide formed from aspartic acid and phenylalanine. It is about 100 times sweeter than cane sugar. However, it readily hydrolyzes and decomposes at elevated temperatures (cooking temperatures), thereby losing its sweetness. Consequently, its application is strictly restricted to cold foods and soft drinks.

Aspirin (acetylsalicylic acid) is produced by the acetylation of salicylic acid ($o$-hydroxybenzoic acid) with acetic anhydride in the presence of an acid catalyst:

$$o-\text{HO-C}_6\text{H}_4-\text{COOH} + (\text{CH}_3\text{CO})_2\text{O} \xrightarrow{\text{H}^+} o-\text{CH}_3\text{COO-C}_6\text{H}_4-\text{COOH} + \text{CH}_3\text{COOH}$$

Salicylic acid is $o$-hydroxybenzoic acid.