Regiodirected synthesis of hydroazolic compounds with the use of thiosemicarbazide

Interaction of α,β-unsaturated ketones of furan series with thiosemicarbazide under basic catalysis leads to 3-furyl-2-thiocarbamoylpyrazolines since nitrous nucleophilic centre of a reagent is activated, whereas the products of intermolecular cyclization of thiosemicarbazones under conditions of acid activation of sulfureous nucleophile are spirocyclic furylmethylene-1,3,4-thiadiazolines.