[Chemistry Class Notes] on Schotten – Baumann Reaction Pdf for Exam

Schotten – Baumann reaction is used for commercial production of amides. It is the method of synthesis of amides by using acid chloride. It is named after German Chemists Carl Schotten and Eugen Baumann, as the reaction was first described by these two chemists in 1883. 

Schotten – Baumann reaction is a condensation reaction of organic chemistry.  In this reaction, acid chloride (acyl halide) or anhydride reacts with amine (primary or secondary) and base to produce amide. The general reaction is given below.

Sometimes this reaction also indicates the reaction between acid chloride (acyl halide) or anhydride with alcohol and base to produce an ester. The general reaction is given below.

Examples of Schotten – Baumann Reaction 

Schotten – Baumann reaction also refers to the benzoylation reaction of active hydrogen-containing compounds. Some examples of the Schotten – Baumann reaction are given below.

Mechanism of Schotten -Baumann Reaction 

The Schotten – Baumann reaction mechanism is given for the reaction of an amine with acid chloride and base. It can be explained by the following two steps: 

Step 1. Attack by Nitrogen Atom of Amine on Carbonyl Carbon of Acyl Halide

The nitrogen atom of the secondary amine has a lone pair of electrons. So, it attacks the carbonyl carbon atom of acyl halide. Thus, the reaction begins. It leads to rearrangement of acyl halide and removal of halide. Thus, nitrogen gets attached with carbonyl carbon of acyl halide. The reaction is given below-

Step 2. Deprotonation: Now the compound formed in step 1 reacts with the base. Hydrogen atoms attached with nitrogen combine with hydroxyl ions of base and form water molecules. Thus deprotonation takes place and nitrogen being more electronegative than hydrogen gets the electrons towards itself and forms amide. The reaction is given below-

Applications of Schotten – Baumann Reaction 

This reaction is widely used in synthesis in organic chemistry. Few applications of this reaction are given below.

• It is used in the synthesis of N-vanillyl nonanamide or capsaicin. 

• It is used in the synthesis of benzamide from benzoyl chloride and phenethylamine. 

• It is used in the acylation of benzylamine. 

• It is used in Fischer’s synthesis of peptides. 

• Products of this reaction such as ester and amides are very useful in many industries such as food, medicine etc. 

It was all about the Schotten – Baumann reaction and its mechanism. If you are looking for more methods of preparation of amides and esters or other name reactions, then explore through our website.

Important Points About the Schotten-Baumann Reaction

The most important point about Schotten-Baumann’s reaction that every student should remember are:

• The Schotten-Baumann reaction of benzoylation of phenols is a very important reaction method in the field of organic chemistry.

• The Schotten-Baumann reaction is named after two German scientists who discovered the reaction.

• The reaction is mainly used in the field of organic chemistry for the benzoylation of phenols with benzoyl chloride.

• The base catalysts that are used in the Schotten-Bauman reaction, to keep the medium of the reaction basic, are sodium hydroxide and pyridine because the reactants involved in the reaction are always acidic.

• The phenol and the base involved in the reaction condition react to give phenoxide ion. Afterward, the benzoyl chloride is attacked by a phenoxide ion. 

• The negative charge prevalent in the reaction shifts to the oxygen molecule present in benzoyl chloride. The negative charge is then utilized to form a double bond between the oxygen atom and the carbon atom.

• Since the carbon atom has the capability of forming only four bonds, the bond present between the carbon atom and the chlorine atom has to break. This bond breaks easily because of the electronegativity difference between the two atoms and the polar nature of the bond. This finally results in the formation of the final product, that is, phenyl benzoate.

• The conditions of the Schotten-Baumann reaction make it easy to perform benzoylation of phenols.

• The same condition of Schotten-Baumann can also be used for carrying out benzoylation of aromatic amines, synthesizing amides from acid chlorides and amines wherein acyl chlorides are reacted with amines to produce amides.

• Apart from the stated above, the reaction can also be used in the synthesis of various compounds and chemicals in the laboratory.