Synthesis of Heterocyclic Compounds, XXXVIII. Five‐membered Heterocycles by Cyclization of 3‐Benzoyl‐4‐oxobutanenitriles

Abstract

Abstract A synthesis of N ‐benzylidene‐2‐furanamines 8 by means of cyanide addition to acylchalcones 2 , followed by piperidine‐catalyzed cyclization in the presence of an aldehyde is reported. The 2‐pyrrolones 4 are formed together with the compounds 8 . In the absence of an aldehyde no furan is obtained. The intermediate 2‐aryl‐3‐benzoyl‐4‐oxo‐4‐phenylbutanenitriles 3 are easily isolated. The N ‐benzylidene‐2‐furanamines 9 are obtained from the oxonitriles 5 .