What Is Rosenmund Reaction?

Charlotte Miller

Are you curious to know what is rosenmund reaction? You have come to the right place as I am going to tell you everything about rosenmund reaction in a very simple explanation. Without further discussion let’s begin to know what is rosenmund reaction?

In the world of organic chemistry, various reactions have been developed to synthesize and transform compounds, contributing to the advancement of pharmaceuticals, materials, and much more. One such significant reaction is the Rosenmund Reaction. Named after the Swiss chemist Karl Wilhelm Rosenmund, this reaction is a catalytic hydrogenation process used to reduce acyl chlorides to aldehydes. In this blog, we will delve into the details of the Rosenmund Reaction, its mechanism, applications, and significance in the world of organic synthesis.

What Is Rosenmund Reaction?

The Rosenmund Reaction is a chemical reaction that falls under the category of catalytic hydrogenation. Its primary purpose is to convert acyl chlorides (acid chlorides) into aldehydes. This transformation is highly valuable in organic synthesis, as aldehydes are versatile compounds with various applications, especially in the pharmaceutical and fine chemical industries.

Reaction Equation:

The Rosenmund Reaction can be represented by the following equation:

RCOCl + H2 -> RCHO + HCl

In this equation, R represents the organic group, and the reaction involves the replacement of the acyl chloride (RCOCl) with an aldehyde (RCHO) through the addition of hydrogen (H2).

Mechanism Of The Rosenmund Reaction

The Rosenmund Reaction is typically carried out under mild conditions, using a palladium catalyst supported on barium sulfate (Pd/BaSO4). The reaction mechanism involves several steps:

  1. Adsorption of Acyl Chloride: The acyl chloride adsorbs onto the surface of the palladium catalyst.
  2. Hydrogenation: Hydrogen gas (H2) is introduced, and the acyl chloride undergoes hydrogenation, which involves the addition of hydrogen atoms to the carbon-oxygen double bond.
  3. Formation of the Aldehyde: After hydrogenation, the acyl chloride is converted into an aldehyde, and hydrogen chloride gas (HCl) is released.
  4. Desorption: The aldehyde product desorbs from the catalyst surface, leaving the palladium catalyst ready for the next cycle.

Applications Of The Rosenmund Reaction

The Rosenmund Reaction has significant applications in the field of organic synthesis:

  1. Pharmaceuticals: The synthesis of aldehydes is an essential step in pharmaceutical manufacturing. Aldehydes are key intermediates in the production of various drugs and pharmaceutical compounds.
  2. Fine Chemicals: The reaction is used to create aldehydes that serve as building blocks for the production of specialty chemicals, perfumes, and flavors.
  3. Agrochemicals: The reaction is used to synthesize aldehydes used in the development of pesticides and agrochemicals.
  4. Research and Development: Organic chemists employ the Rosenmund Reaction in laboratories for the synthesis of specific aldehydes needed for their research and development projects.
  5. Inhibition of Further Reduction: The Rosenmund Reaction is an effective method for selectively reducing acyl chlorides to aldehydes without further reduction to alcohols, which can be achieved with traditional hydrogenation.


The Rosenmund Reaction is a powerful tool in the organic chemist’s arsenal, facilitating the transformation of acyl chlorides into valuable aldehydes. Its applications span a wide range of industries, from pharmaceuticals to agrochemicals and fine chemicals. The ability to selectively synthesize aldehydes without over-reduction sets the Rosenmund Reaction apart as a crucial process in modern organic synthesis, contributing to advancements in various fields and the development of new and improved products.


What Is Rosenmund Reaction Class 12th?

The Rosenmund reaction is a hydrogenation process where molecular hydrogen reacts with the acyl chloride in the presence of catalyst – palladium on barium sulfate. Barium sulfate reduces the activity of the palladium due to its low surface area, thereby preventing over reduction.

What Is An Example Of A Rosenmund Reaction?

An example is benzoyl chloride (an acid chloride) reacts with hydrogen and Pd/BaSO4 (a poisoned catalyst) to produce benzaldehyde.

What Is The Rosenmund And Gatterman Reaction?

Hint:The Rosenmund reduction reaction is a hydrogenation reaction in which acyl chloride is converted to aldehyde. The Gatterman-Koch reduction reaction is a reaction in which the benzene molecule is converted to benzaldehyde.

What Is The Difference Between Lindlar And Rosenmund?

Lindlar’s catalyst produces alkenes and Rosenmund catalyst produces aldehyde. Methanal cannot be produced by this method. S:- when aldehyde is formed sulphur helps to prevent its hydrogenation immediately. Hence it does not act as a poison.

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