Sulfated tin oxide (SO4-2/SnO2): an efficient heterogeneous solid superacid catalyst for the facile synthesis of 2,3-dihydroquinazolin-4(1H)-ones

A novel methodology for the facile synthesis of 2,3-dihydroquinazolin-4(1H)-ones by using sulfated tin oxide (SO4-2/SnO2) as a heterogeneous solid superacid catalyst is reported. SO4-2/SnO2 has been characterized by various spectroscopic techniques. The surface area of mesoporous SO4-2/SnO2 was found to be 32.015 m(2) g(-1) with a pore diameter of 7.10 nm and pore volume of 0.056838 cm(3) g(-1) by using BET analysis. The crystallite size of 6.58 nm with the loading of 1.21 mmol g(-1) sulfate groups was analyzed by XRD and EDX techniques. SO4-2/SnO2 displayed excellent catalytic activity in the cyclocondensation of 2-aminobenzamide with a variety of substituted aryl aldehydes affording corresponding 2,3-dihydroquinazolin-4(1H)-ones in good to excellent yields using ethanol as a solvent. SO4-2/SnO2 could be easily separated from the reaction mixture by simple filtration and reused six times without any significant loss in the catalytic activity. [GRAPHICS] .

Automated summary

A novel methodology for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones using sulfated tin oxide as a catalyst has been reported. The catalyst exhibited excellent catalytic activity in the cyclocondensation reaction and could be easily separated and reused multiple times.