Question

In the Gabriel synthesis of primary amines, N-potassiophthalimide is used as a source of the nitrogen atom. Complete the synthesis reactions by drawing the missing structures. Ignore inorganic counterions.

Answer 1

Step 1. A new bond C-N is formed when the nucleophile 'N, attacks on the electrophile 'c' of the alkyl halide by displacing the bromide ion. on the electrophile C of Br DMF 1,3-dioxoisoindolin-2-ide 2-(sec-butylDisoindoline-1,3-dione Step 2. In this step, 2-(sec-butyl) isoindoline-1,3-dione will react with NaOH and nucleophilic addition of OH will take place. Phthalate is formed as a product in the reaction.

он љ NaOH 2-(sec-butyl)isoindoline-1,3-dione но H20 NaOH phthalate

Answer 2

Concepts and reason

The concept used is to identify the missing products of Gabriel synthesis reaction.

Fundamentals

Gabriel synthesis is the method of preparation of primary amines. Potassium phthalimide is the source for N atom that is first treated with base, followed by a primary alkyl halide. It produces N-alkyl phthalimide. This undergoes acidic or basic hydrolysis to produce the primary amine and the corresponding by-product.

Under acidic hydrolysis, hydrazine is used and 2,3-dihydrophthalazine-1,4-dione is produced at the end of the reaction.

Under basic hydrolysis, a strong base like ${\rm{NaOH}}$ is used and sodium phthalate is produced.

The reaction of potassium phthalimide reacts with alkyl halide in the presence of DMF is as follows:

The hydrolysis of N-alkyl phthalimide in the presence of ${\rm{NaOH}}$ and water is as follows:

Ans:

The complete reaction is as follows:

Answer 3