A series of 13 aryl indeno[2′,1′:5,6]pyrido[2,3- d]pyrimidine-2,4,6-(3 H,5 H,11 H)-triones, eight of which are new, were synthesised regioselectively in high yields by a three-component reaction of 1,3-indanedione, an araldehyde and 6-aminopyrimidin-2,4(1 H,3 H)-dione in the presence of a deep eutectic solvent comprised of choline chloride/urea (1:2) as the catalyst. The reaction conditions were mild and did not require additional catalysts. Given the inexpensive, nontoxic and recyclable nature of the deep eutectic solvent, these reaction conditions are simple to carry out and environmentally friendly.

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-aminopyrimidin-2,4(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.