Efficient and facile synthesis of 5-arylindeno[2′,1′:5,6]pyrido[2,3-d] pyrimidine-2,4(3H)-dione and 7-arylbenzo[h]pyrimido[4,5-b]quinoline-8,10(5H,9H)-dione under mild conditions

Annulations involving 1-indanones to access fused- and spiro frameworks

“…Rong et al carried out the one-step synthesis of indeno-fused pyridopyrimidine scaffolds 51 involving readily accessible 2-arylidene 1-indanone system under mild reaction conditions. 46 The authors employed 6-amino-1,3-dimethylpyrimidine 50 as the annulation partner to react with 2-arylidene 1-indanone 49 in the presence of catalytic amount of p -TsOH in refluxing acetonitrile resulting polyheterocyclic compounds 51 in excellent yields (Scheme 14). The reaction was also applicable for 2-arylidene dihydronaphthalenone systems.…”