ChemInform Abstract: Reaction of 2‐Aroylbenzoic Acids with 4‐Nitro‐ and 2,4‐Dinitrophenylhydrazine.

Abstract

ChemInform Abstract Little is known to date about the reaction between 2-aroylbenzoic acids and arylhydrazines. Hence, this reaction is studied. The acid-catalyzed reaction between the 2-aroylbenzoic acids (I) and 2,4-dinitrophenylhydrazine (II) yields the stable hydrazones (III) which are dehydrated by Ac2O (in the presence of NaOAc) to give the phthalazinones (IV), whereas the reaction between the acids (I) and p-nitrophenylhydrazine (V) affords the phthalazinones (VI) in one step. No formation of stable hydrazones is observed during the reaction. This difference in the behavior of the arylhydrazines is ascribed to the fact that the hydrazones (III) are sufficiently stabilized in the presence of two nitro groups.