“…Alum, well known for its traditional role in water treatments (coagulation and clarification) has recently been reported as a reusable, cheap and excellent catalyst for the preparation of organic compounds, for example, in the transesterification of palm oil [28], synthesis of -aminophosphonates [29], 2,3dihydroquinazolin-4(1H)-ones [30], 1,3,4-Oxadiazoles [31], di-hydropyrimidinones [32], cis-isoquinolonic acids [33], pyrroles [34] and coumarins [35]. Thus, continuing our research on new one-pot reactions, we considered Alum to be ideal for affecting the synthesis of mono-and bis-2amino-4H-pyrans via a three-or pseudo five-component reaction of 4-hydroxycoumarin, malononitrile and aldehydes in ethanol/water media at room temperature.…”