Tandem Knoevenagel-Michael-cyclocondensation reaction of malononitrile, various aldehydes and barbituric acid derivatives using isonicotinic acid

The synthesis of pyrano[2,3-d]pyrimidine dione derivatives is important due to their significant antitumor, antibacterial, antihypertensive, hepatoprotective, cardiotonic,vasodilator, bronchiodilators and antiallergic properties [1]. Also, some of them can be widely used as antimalarial, antifungal, analgesics and herbicidal materials [2,3].Having this issue in mind, we have synthesized pyrano[2,3-d]pyrimidine dione derivatives by the tandem Knoevenagel-Michael-cyclocondensation reaction of malononitrile, various aldehydes and barbituric acid derivatives in the presence of isonicotinic acid (Scheme 1).