Chapter 20, Problem 18PP

Interpretation Introduction

Interpretation:

Using aniline as a starting material and 2-aminothiazole, the synthesis of sulfathiazole is to be shown and the conversion of sulfathiazole to succinylsulfathiazole is to be provided.

Concept Introduction:

▸ Electrophiles are electron deficient species which has positive or partially positive charge. Lewis acids are electrophiles which accept electron pair.

▸ Nucleophiles are electron rich species which has negative or partially negative charge. Lewis bases are nucleophiles which donate electron pair.

▸ Free radical is an atom, molecule or ion that has an unpaired electron which makes it highly chemically reactive.

▸ Substitution reaction: A reaction in which one of the hydrogen atoms of a hydrocarbon or a functional group is substituted by any other functional group is called substitution reaction.

▸ Elimination reaction: A reaction in which two substituent groups are detached and a double bond is formed is called elimination reaction.

▸ Addition reaction: It is the reaction in which unsaturated bonds are converted to saturated molecules by the addition of molecules.

▸ Aniline and substituted aniline reacts with nitrous acid at low temperature to form benzene diazonium salts.

▸ The reduction of nitro group results in the formation of primary amine.

▸ Electrophiles are electron deficient species which has positive or partially positive charge. Lewis acids are electrophiles which accept electron pair.

▸ Carboxamide undergoes hydrolysis more rapidly than sulfonamide.

▸ The aniline undergoes acetylation to protect the amino group and form acetanilide.

▸ Acetanilide undergoes the electrophilic aromatic substitution on reaction with chlorosulfonic acid and yield $p-\text{acetamidobenzenesulfonyl}$.

▸ Addition of $2-\text{aminothiazole}$ to $p-\text{acetamidobenzenesulfonyl}$ and refluxing with dilute hydrochloric acid leads to the formation of sulfathiazole.

▸ The sulfathiazole reacts with the succinic anhydride which leads to the formation of final product that is succinylsulfathiazole.