Green and Efficient Synthesis of a Novel Series of Indeno-Fused Pyrido [2,3-d] Pyrimidines Using Choline Hydroxide as EcoFriendly Catalyst in Water

Abstract

A series of 13 aryl indeno[2’,1’:5,6]pyrido[2,3-d]pyrimidine-2,4,6-(3H,5H,11H)-triones, 8
of which are new, were synthesized regioselectively in high yields by a threecomponent reaction of 1,3-indanedione, an araldehyde and 6-aminopyrimidin2,4(1H,3H)-dione in the presence of choline hydroxide as catalyst in water. The reaction
conditions were mild and did not require additional catalysts. Given the inexpensive,
nontoxic, and recyclable nature of the choline hydroxide, these reaction conditions are
simple to carry out and environmentally friendly.