A concise and efficient approach to tetrakis(uracil) derivatives by the reaction of bis(aldehydes) with four equivalents of 6-aminouracil is reported. Also, the synthesis of bis(pyrimido[4,5-b]quinolones) and bis(indeno-[2',1':5,6]pyrido[2,3-d]pyrimidine) derivatives has been accomplished by a three-component reaction involving bis(aldehydes), 6-aminouracil and the appropriate cyclic 1,3-diketone. The method involves domino Knoevenagel condensation / Michael addition reaction sequences.
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