Application of N‐Acylimidazoles in the Claisen Condensation Reaction

The Claisen condensation reaction is a classical method used for the formation of C−C bonds. Homo‐ and cross‐Claisen condensation reactions are usually carried out using a Ti(IV)‐based reagent at ultra‐low‐temperatures. In this report, intermediate β‐keto acyl imidazoles were synthesised using a sodium imidazolide‐catalysed homo‐ and cross‐condensation reaction of N ‐acyl imidazoles performed under mild conditions and subsequently used to prepare a range of β‐keto esters and ketones via alcoholysis or hydrolysis. This method is particularly suitable for the synthesis of isotopically‐labelled acetylacetic ester compounds. N ‐acyl imidazole compounds are useful reactants for the Claisen condensation reaction.