Mannich Reaction

German Chemist: Carl Ulrich Franz Mannich

Mannich Reaction is named after German Chemist Carl Ulrich Franz Mannich who gave the mechanism of the reaction in 1912. It is a nucleophilic addition reaction. Mannich reaction can also be considered as condensation reaction. As it involves condensation of an enolized carbonyl group and non-enolized aldehyde (such as formaldehyde). In this article we will discuss mannich reaction, mechanism of mannich reaction, mannich reaction examples and applications of mannich reaction. 


The Mannich Reaction 

The amino alkylation reaction which involves condensation of an enolizable carbonyl compound with a non- enolizable aldehyde (such as formaldehyde) and primary or secondary amine or ammonia to form mannich base is called Mannich Reaction. An acid or a base can act as catalyst in the reaction. 

Mannich base is the product of Mannich Reaction which is -amino carbonyl compound. 

Mannich Reaction (in words) – 

1 or 2 

amine/ ammonia

Non-enolizable

Aldehyde

(such as formaldehyde)

Enolizable

Carbonyl compound

-amino carbonlyl compound 

(Mannich Base)


+ + 🡪 

Enolizable carbonyl compound or aldehyde – Which has one or more alpha hydrogen. 

Examples- 

Non-enolizable aldehyde - Which has no alpha hydrogen. 

Examples -          

Examples of Mannich Reaction 

We have illustrated few examples of Mannich Reaction for your better understanding –     

Mannich Reaction Mechanism 

We can illustrate Mannich reaction mechanism by following steps – 

Step -1 Formation of iminium ion – 

Iminium ion is formed by the reaction between primary or secondary amine or ammonia and formaldehyde. The reaction is illustrated below –                                                                                           

Step – 2 Formation of enol form of the compound containing carbonyl group – 

Carbonyl compound forms enol form of it by tautomerization. Then enol form of the compound containing carbonyl group takes the reaction further. The reaction is illustrated below.

Step- 3 Formation of Mannich Base 

In this step enol form of the carbonyl compound attacks on iminium ion which forms -amino carbonyl compound or Mannich base. The reaction is illustrated below –                                                                                                      

Applications of Mannich Reaction                           

Mannich reaction is an organic reaction which has numerous applications in many fields. We are illustrating few applications of Mannich Reaction here – 

  1. It is used in the synthesis of many medicinal compounds such as tramadol. Reaction involved is given below - 

  1. It is used in the synthesis of other organic compounds such as peptides, nucleotides, antibiotics, tropinone etc. 

  2. It is used in the production of agro chemicals, plant growth regulators etc. 

  3. It is used in many reactions in polymer chemistry. 

  4. It is used to synthesized alkyl amines.

  5. It is used in converting non-polar hydrocarbons into detergents and soaps. 

  6. It is used in production of many cleaning materials (chemicals), epoxy coatings, automotive fuel treatments etc. 

     We hope that you must have got an idea about Mannich Reaction and its mechanism through this article.  If you have doubts related to other name reactions as well then visit many more such pages related to name reactions available at Vedantu. You can register yourself on Vedantu and access free PDFs of NCERT Solutions, study material and sample papers available on Vedantu.