Pharmacy Pharmaceutical Chemistry 3

Question 1

Which chemical reaction is used in the synthesis of esters from carboxylic acids?

Accepted Answer

Fischer esterification

Answer

Fischer esterification involves the acid-catalyzed condensation of a carboxylic acid with an alcohol to form an ester and water.

Question 2

The term 'bioisostere' in medicinal chemistry refers to:

Accepted Answer

A substituent or group that produces similar biological effects to another group

Answer

Bioisosteres are atoms or groups that produce broadly similar biological activity due to similar size, electronegativity, or electronic effects.

Question 3

Which oxidation state characterizes a sulfonic acid group (-SO3H)?

Accepted Answer

+6

Answer

In a sulfonic acid (-SO3H), sulfur has an oxidation state of +6, the same as in sulfuric acid H2SO4.

Question 4

In pharmacokinetics, the concept of 'ionization trapping' in the stomach means that:

Accepted Answer

Basic drugs are trapped in the stomach because ionization reduces membrane permeability

Answer

Basic drugs become protonated (ionized) in the acidic stomach environment, making them water-soluble but membrane-impermeable, trapping them in the gastric lumen.

Question 5

Which reaction converts a primary amine to a diazonium salt?

Accepted Answer

Diazotization (with NaNO2/HCl)

Answer

Diazotization reacts a primary aromatic amine with sodium nitrite (NaNO2) in acidic (HCl) conditions at 0–5°C to form a diazonium salt (ArN2+Cl-).

Pharmacy Practice Test

Pharmacy Practice Test

Pharmacy Pharmaceutical Chemistry 3