Application of a functionalized mesoporous silica catalyst to the synthesis of tetrazoles†
In the present study, well ordered MCM-41 was synthesized and functionalized with benzyl group and subsequently sulfonated with chlorosulfonic acid. The functionalized catalyst (MCMBSA) was characterized by XRD, TGA, FTIR, TEM, BET, and SEM. 5-Aryl-1H-tetrazoles were synthesized by the reaction of the corresponding aryl nitriles and sodium azide catalyzed by MCMBSA. The mole ratio of nitrile to sodium azide, the amount of catalyst, reaction times, and solvent type were optimized. The MCMBSA catalyst was more effective than the catalyst obtained from the direct sulfonation of MCM-41. The versatility of the method was investigated by using various nitriles, which showed reasonable yields of tetrazoles. The regeneration and reusability of catalyst was also examined.