An efficient one-pot three-component synthesis of novel derivatives of pyrido[2,3-d]pyrimidines by using nanocatalyst [-Fe2O3@HAp-SO3H]

Pyrido[2,3-d]pyrimidine derivatives possess wide range of physiological properties, which include antibacterial, diuretic, analgesic, anti-inflammatory, antipyretic, antitumoral [1]. On the other hand 6-aminouracil and thiouracil derivatives find wide applications as starting materials for the synthesis of fused pyrimidines such as pyridopyrimidines. Based on our continued program in developing biologically important heterocycles [2,3]. we report here a convenient and practical method for the synthesis of new derivatives of pyrido[2,3-d]pyrimidines by using [-Fe2O3@HAp-SO3H] as recyclable nanocatalyst. In this protocol the reaction of 3-(1-methyl-1H-pyrrol-2-yl)-3- oxopropanenitrile (1 mmol) (1), 6-amino-2-(alkylthio)pyrimidin-4(3H)-one (1 mmol) (2), arylaldehyde (1 mmol) (3) and [-Fe2O3@HAp-SO3H] (0.01 g) in DMF (3 mL) washeated under reflux. The reaction furnished the desired products in reasonable reaction times (7-14 min) and high yields (84-90%) (Scheme 1). The structures of all the prtoducts were established by spectroscopic (IR, 1H NMR, 13C NMR) analysis