Grosheintz-Fischer-Reissert aldehyde synthesis

What is Grosheintz-Fischer-Reissert aldehyde synthesis?

The Grosheintz-Fischer-Reissert aldehyde synthesis, also known as the Reissert aldehyde synthesis, was initially reported by Reissert in 1905 and later extended by Grosheintz and Fischer in 1941. This reaction involves the synthesis of aldehyde via the formation of 1-acyl-2-cyano-1,2-dihydroquinoline derivatives from acyl chlorides, quinoline, and potassium cyanide KCN, followed by the hydrolysis of these derivatives under acidic conditions to produce quinaldic acid and aldehydes.

Grosheintz-Fischer-Reissert aldehyde synthesis - general reaction scheme - Reissert aldehyde synthesis
Grosheintz-Fischer-Reissert aldehyde synthesis

While the original procedure occurs smoothly for aroyl or cinnamoyl chloride in liquid SO2, it is not effective in solvents such as benzonitrile, ether, dioxane, acetone, or CHCl3. However, the modification from Grosheintz and Fischer using hydrogen cyanide and 2 eq. quinoline in absolute benzene is adaptable for aliphatic acid chlorides.

This method is considered superior to the normal Rosenmund reduction as it can convert acyl chlorides into aldehydes that cannot be achieved through Rosenmund reduction. For example, o-nitrobenzoyl chloride has been converted into o-nitrobenzaldehyde in 60 % yield through this reaction.

On the other hand, the Rosenmund reduction is not suitable for such conversion.

The Grosheintz-Fischer-Reissert aldehyde synthesis has a broad range of applications in the synthesis of aldehydes, particularly in the synthesis of aromatic aldehydes.