An Efficient synthesis of pyrimido[4,5‐<i>b</i>]quinoline and indeno[2′,1′:5,6]pyrido[2,3‐<i>d</i>]pyrimidine derivatives via multicomponent reactions in ionic liquid

Abstract

Abstract magnified image A series of pyrimido[4,5‐ b ]quinoline and indeno[2′,1′:5,6]pyrido[2,3‐ d ]pyrimidine derivatives were synthesized via the three‐component reaction of an aldehyde, 6‐aminopyrimidine‐2,4‐dione and 5,5‐dimethyl‐1,3‐cyclohexanedione or 1,3‐indanedione in ionic liquid 1‐ n ‐butyl‐3‐methylimidazolium bromide ([bmim]Br). This protocol has the advantages of easier work‐up, milder reaction conditions, high yields and an environmentally benign procedure compared with other methods.