Question

Show how you would use bromination followed by amination to synthesize the following amino acids.

1. Glycine (b) Leucine (c) Glutamic acid

Short answer

a)

Formation of glycine

b)

Formation of leucine

c)

Formation of glutamic acid

Step-by-step solution

Formation of glutamic acid

The Hell-Volhard-Zelensky reaction is a halogenation reaction and mostly involves the halogenation of carboxylic acid at the alpha carbon. The reagents used are phosphorus tribromide and dibromide.

Further solution

The introduction of bromine at the position of a carboxylic acid is given by the Hell-Volhard-Zelensky reaction. In the first step of this reaction, a carboxylic acid is transformed into an $\mathrm{\alpha }$Bromo-acid by using ${\mathrm{Br}}_2$and ${\mathrm{PBr}}_{3\left\{\right\}}$ . The second step of the reaction represents ${\mathrm{Sn}}^2$a reaction in which ammonia replaces bromine.

(a)

The synthesis of glycine by using bromination followed by amination is as shown below:

Formation of glycine

(b)

The synthesis of leucine by using bromination followed by amination is as shown below:

Formation of leucine

(c)

The synthesis of glutamic acid by using bromination followed by amination is as shown below:

Formation of glutamic acid