Beckmann rearrangement

1. BECKMANN
REARRANGEMENT
PRESENTED BY:
YEHTESHAM KHURSHID
M.PHARM PHARMACEUTICAL CHEMISTRY
FIRST SEMESTER
SPER, JAMIA HAMDARD

2. CONTENTS
1.INTRODUCTION
2.MIGRITORY APTITUDE
3.GENERAL REACTION
4.EXAMPLE OF REACTION
5.MECHANISM OF REACTION
6.APPLICATION
7.REFERENCES

3. INTRODUCTION
✔ The Beckmann rearrangement reaction is one of the most
employed reaction in many sector to convert oximes to amides.
This reaction is discovered by the chemist Ernst otto Beckmann
in the mid-1880.
✔ The Beckmann rearrangement is the acid catalyzed conversion of oximes
into their corresponding amides that allows the insertion of nitrogen atom
from the C=N double bond into the carbon chain forming a C-N single
bond.
✔ The reaction involves migration of group from carbon to
nitrogen.
✔ Concentrated Sulphuric acid , Hydrochloric acid, Phosphorus
pentachloride, Phosphorus tetrachloride, Sulphonyl chloride
and Zinc oxide are generally used as reagent.

4. MIGRATORY APTITUDE
✔ The migration of group depends not on the migration
aptitude but upon the orientation of the group in
relation to –OH group. It is found that the migration
group is always anti to –OH group and thus the
rearrangement is said to be stereospecific.
✔ When chiral groups are present ,they migrate
intramolecularly with retention of configuration.
✔ Migratory aptitude- Phenyl > Ethyl> Methyl

5. GENERAL REACTION
.

6. EXAMPLE OF REACTION
Initially in 1883 it was being done by chemist Alois Janny who was working
with ketoxime and phosphorus pentachloride but he was not able to
recognize the product , however later on it was confirmed by Beckmann
that the product was benzanilide which were obtained by reaction of
ketoxime(benzophenone oxime) , acetic anhydride, acetic acid and
hydrochloric acid.

7. Caprolactam was discovered by Otto Wallach in 1900 and its commercial
synthesis of acid catalysed Beckmann rearrangement of Cyclohexanone
oxime.

8. MECHANISM OF REACTION
⮚ Protonation of oxime
• The protonation at the oxygen atom of oxime gives
oxonium cation.
⮚ Migration of alkyl group
• The alkyl group transfer to nitrogen atom followed by
removal of water molecule that lead to formation
nitrilium cation.
⮚ Hydrolysis of nitrilium cation
• The nitrilium cation get hydrolysed to give an amide as
the final product in the presence of basic medium .

9. oxime
Amide

10. APPLICATION
● Synthesis of isoquinoline:

11. •Synthesis of Nylon 6:

12. ● Synthesis of Lactams:
Synthesis of lactams Alicyclic ketones of all ring sizes undergo the
Beckmann rearrangement of their oximes to yield lactams.
A product of considerable industrial importance is perlon (valuable
textile polymer) which is prepared from w-caprolactam. This is
obtained by the Beckmann rearrangement of cyclohexanone oxime
It is synthesized from phenol.

13. References
✔ Morrison , R. T &Boyed, R.N, organic chemistry
✔ March , J, advanced organic chemistry, Wiley eastern limited
✔https://chemistnotes.com
✔ https://www.organic-chemistry.org
✔ https://www.chemistrylearner.com/beckmann-rearrangement.
✔ P.Yan , P. Batamack, G.K.S Prakash and G.A Olah,Catal.Lett,2005,
page103 and 165-168.
✔ S. Srivastava and K. Kaur, New J. Chem, 2020, page no-3

14. THANK YOU