Rosenmund–von Braun reaction explained

The Rosenmund–von Braun synthesis is an organic reaction in which an aryl halide reacts with cuprous cyanide to yield an aryl nitrile.^{[1] [2] [3]}

The reaction was named after Karl Wilhelm Rosenmund who together with his Ph.D. student Erich Struck discovered in 1914 that aryl halide reacts with alcohol water solution of potassium cyanide and catalytic amounts of cuprous cyanide at 200 °C. The reaction yields the carboxylic acid, not the nitrile, but Rosenmund speculated that the intermediate should be the nitrile, since nitriles on aromatic rings can react to form carboxylic acids.^[1] Independently Alfred Pongratz^[4] and ^[2] improved the reaction by changing the reaction conditions to higher temperatures and used no solvent for the reaction. Further improvement of the reaction was done in the following years,^[5] for example the use of ionic liquids as solvent for the reaction.^[6]

See also

• Kolbe nitrile synthesis a similar reaction for the synthesis of alkyl nitrile
• Sandmeyer reaction
• Von Braun reaction

Notes and References

1. Rosenmund. Karl W.. Struck. Erich. Das am Ringkohlenstoff gebundene Halogen und sein Ersatz durch andere Substituenten. I. Mitteilung: Ersatz des Halogens durch die Carboxylgruppe. Berichte der Deutschen Chemischen Gesellschaft (A and B Series). 27 September 1919. 52. 8. 1749–1756. 10.1002/cber.19190520840.
2. v. Braun. Julius. Manz. Gottfried. Fluoranthen und seine Derivate. III. Mitteilung. Justus Liebig's Annalen der Chemie. 1931. 488. 1. 111–126. 10.1002/jlac.19314880107.
3. E. Callen. Joseph. A. Dornfeld. Clinton. H. Coleman. George. 9-CYANOPHENANTHRENE. Organic Syntheses. 28. 1948. 28. 34. 10.15227/orgsyn.028.0034.
4. Pongratz. Alfred. Untersuchungen über Perylen und seine Derivate. Monatshefte für Chemie. July 1927. 48. 7. 585–591. 10.1007/BF01518076. 197767053.
5. KOELSCH. C. F.. WHITNEY. A. G.. THE ROSENMUND-von BRAUN NITRILE SYNTHESIS. The Journal of Organic Chemistry. November 1941. 06. 6. 795–803. 10.1021/jo01206a002.
6. Wu. Jeff Xin. Beck. Brandon. Ren. Rex X.. Catalytic Rosenmund–von Braun reaction in halide-based ionic liquids. Tetrahedron Letters. January 2002. 43. 3. 387–389. 10.1016/S0040-4039(01)02168-2.