Pyrazolidine-3,5-diones with heterocyclic substituents. I. Preparation of 3-Phenyl-1,2,4-triazolyl derivatives

Abstract

The preparation of pyrazolidine-3,5-diones substituted in the 1- position by 3-phenyl-1,2,4-triazol-5-yland mono- or di-substituted in the 4-position by aliphatic or carbocyclic groups is described, together with that of some further substituted derivatives and byproducts, including s-triazolo[1,5-a]-pyrimidines. Attention is drawn to problems of tautomerism and reactivity which are to be treated in subsequent papers.