An efficient synthesis of 2H-chromen-3-yl derivatives via CuI/(NH 4) 2 HPO 4 catalyzed reaction of O-propargyl salicylaldehydes with active methylene compounds
2H-Chromen-3-yl-methylenemalononitriles/cyanoacrylates/cyanoacrylamides with variant structural features have been serendipitously formed during an endeavour to prepare 5H- chromeno [3, 4-c] pyridine using CuI/(NH4) 2HPO4 catalyzed reaction of O-propargyl salicylaldehyde with malononitrile/ethyl cyanoacetate/cyanoacrylamide. The process is convenient, speedy and high yielding, and the products formed have been finally ...