An improved synthetic strategy for 1-substituted 4-H phthalazines using a convenient, three-step reaction sequence under mild conditions is described. The protocol involves condensation of hydrazine hydrate with o-ketobenzaldehydes derived through the Pb(OAc)4 oxidation of the N-acylhydrazones of salicylaldehydes. This pathway is of high practical value since a wide variety of substituted acylhydrazides