Beckmann Rearrangement

Beckmann Rearrangement

What is Beckmann Rearrangement?

The Beckmann Rearrangement is a reaction of the oximes that can bring about either nitriles or amides, contingent upon the beginning material. These Oximes that obtained from the ketones develop into amides; oximes got from the aldehydes shape into nitriles.

The Beckmann Rearrangement process is a natural reaction that is useful in changing an oxime to that of an amide under some acidic conditions. The reaction eventually starts by the process of protonation of the alcohol group gather shaping a preferred leaving group.

The R group transition to that of the leaving species then moves to the nitrogen, bringing about a carbocation and the arrival of a water particle. The water atom attacks the carbocation, and after the process of deprotonation and tautomerization, the amide is obtained.

In simple, Beckmann Rearrangement is a reaction where oxime is changed over to an amide. The oxime is processed by treating an aldehyde or a ketone with hydroxylamine. This Beckmann Rearrangement reaction, named after Ernst Otto Beckmann, a German scientist.

Mechanism:

Beckmann Rearrangement

The process of Beckmann Rearrangement is as shown below-

  1. The oxime is shaped when cyclohexanone responds with the hydroxylamine.
  1. The Protonation of hydroxyl of oxime happens after the change of the alkyl substituent “trans” to the nitrogen
  1. At the same time, the N-O bond is severed with the expulsion of water.
  1. Later, Isomerization process happens which protonates the molecule of nitrogen and then prompts to the production of amine.

Applications:

Some of the uses of this reaction are as below-

  • It is used in the industries for the synthesis of paracetamol. This integration is achieved by the process of conversion of a ketone to ketoxime with the help of hydroxylamine.
  • It is mainly used in the synthesis of various steroids and drugs
  • The Beckmann Rearrangement synthesis is helpful in the production of some of the chloro bicyclic lactams.

Practise This Question

Which of the following produces PCl3 ?