What is the Rosenmund Reduction Reaction

The Rosenmund reduction is a chemical reaction.

In the Rosenmund reduction, aldehydes are produced by reducing carboxylic acid chlorides with hydrogen. Palladium on barium sulfate is used as a carrier. Since a reduction to alcohol can occur with untreated palladium, the activity of the catalyst is reduced by poisoning (e.g. with quinoline / sulfur). The hydrogen chloride formed in the course of the reaction is either driven out of the reaction mixture by the stream of hydrogen or can be bound by adding suitable bases (e.g. amines). Furthermore, the reaction must be carried out with the exclusion of water, since otherwise the acid chloride is hydrolyzed to the corresponding carboxylic acid. Acid chlorides react with carboxylic acids to form carboxylic acid anhydrides. Further by-products are the esters formed from the alcohols and the carboxylic acid chloride.

The reaction is named after its discoverer, Karl Wilhelm Rosenmund.


  1. Rosenmund, K. W. Reports of the German Chemical Society1918, 51, 585 [1]
  2. Saytzeff, Michael; Journal for Practical Chemistry1873, 6(1) , 128-135. [2]


  • Laue, T .; Plagens, A .: "Name and Keyword Reactions in Organic Chemistry". 3. Edition. Stuttgart: Teubner Study Books Chemistry (1998).

Category: Name Reaction