Reactions between aromatic nitro-compounds and hydroxylamines in alkaline solution. Part I. Kinetic studies

Abstract

An e.s.r. study shows that the initial reactions in alkali under nitrogen between an aromatic nitro-compound and hydroxylamine or a monosubstituted hydroxylamine are (i)–(iv). K,k₁, and k₂ have been evaluated by monitoring RNHOH + OH^– [graphic omitted] RNHO^–+ H₂O (i), ArNO₂+ RNHO^– [graphic omitted] (ArNO₂·)^–+ RNHO·(ii), 2(ArNO₂·) [graphic omitted] Products (iii), 2RNHO· [graphic omitted] Products (iv) the build-up and decay of (ArNO₂·)^– radical-anions by use of p-nitrobenzoic acid and N-methyl-, N-benzyl-, and N-diphenylmethyl-hydroxylamines.

With hydroxylamine the kinetic measurements are much less accurate owing to a pseudo-unimolecular gas evolution which appears to come from reactions (v). Hydroxylamine is also destroyed by reaction (vi), the 2NH₂O·→ H₄N₂O₂→ N₂+ 2H₂O (v), ArNO + 2NH₂OH → ArN₃+ 3H₂O (vi) nitroso-compound being formed by the disproportionation (iii).