Alkali metal adducts of benzophenone azine. I. The sodium and potassium adducts

Abstract

Contrary to previous reports, the reaction between benzophenone azine and sodium or potassium produces an adduct containing 2 g-atoms of alkali metal per mole of azine. The chemical reactions of this dianion have been examined and a 1,2-dianionic structure is most consistent with its chemical behavior.Treatment of the adduct with methyl iodide, 1,3-dibromopropane, or 1,4-dibromobutane results in alkylation on the benzylic carbon and adjacent nitrogen. However, regeneration of benzophenone azine occurred with methylene iodide, 1,2-dibromoethane, and benzyl chloride.With ethyl chloroformate, reaction occurred at the carbanionic center to form an intermediate unstable anion. This anion could be protonated or alkylated but if allowed to stand, decomposed to diphenyldiazomethane and the anion of ethyl diphenylacetate.Reaction of the benzophenone azine dianion with methyl benzoate is quite complicated and leads to substantial amounts of benzophenone azine being regenerated by electron transfer. That portion of the dianion which is not converted to azine reacts with methyl benzoate to produce the anion of α-benzamido- α,α-diphenylacetophenone.The possibility that an adduct of N-benzoyl benzophenone imine is an intermediate in this last reaction is examined and rejected.