application of sulfamic acid@nano sio2 as an efficient heterogeneous catalyst for synthesis of 2-amino-dihydropyranopyran-3-carbonitriles in water

An efficient one-pot green procedure for the synthesis of 2-amino-dihydropyrano[3,2-b]pyran-3- carbonitriles has been reported via three-component condensation of kojic acid, malononitrile and aldehydes in aqueous media at ambient temperature using sulfamic acid@nano sio2. this methodology has valuable advantages such as convenient one-pot operation, short reaction times, environmentally friendly conditions, ease of catalyst recovery and the use of water as reaction media.