Sulfonic acid decorated graphene oxide (GO-SO₃H): a efficient heterogeneous catalyst for synthesis of tert-butyl/ethylacetate and pyrazole disubstituted tetrazole derivatives

A simple and straightforward synthetic strategy has been established toward furnishing of promising bis-heterocyclic pyrazole containing substituted tetrazole derivatives which might be proved as valuable molecules because of the presence of medicinally and biologically important pyrazole and tetrazole entities. Sulfonic acid decorated graphene oxide (GO-SO3H), a new class of heterogeneous carbo-catalyst was first time reported for synthesis of tert-butyl/ethyl acetate and pyrazole-substituted tetrazole through one-pot 4-C reaction. The synthesized GO-SO3H catalyst offered more than 95% yields of tetrazoles with a broad range of substrates including different substituted aldehyde, isocyanide, and amine within 15-20 min under mild reaction conditions. In addition, sulfonic acid decorated graphene oxide (GO-SO3H) was reused up to five reaction cycles without considerable drop in its catalytic efficiency. The formation of all synthesized pyrazole containing substituted tetrazole derivatives was confirmed by various spectroscopic techniques.