In alkaline solution, 4-nitrophenyl N-hydroxycarbamate undergoes reaction by elimination to yield 4-nitrophenoxide ion, and by rearrangement to yield N-carboxy-4-nitrophenoxyamine. The effect of pH on the yield of the rearrangement product establishes that a transient spiro Meisenheimer complex is formed reversibly. Aromatization of this species occurs by two competing pH-independent reactions: one
在碱性溶液中,4-
硝基苯基
N-羟基氨基甲酸酯通过消除反应生成4-
硝基苯氧离子,并通过重排生成N-羧基-4-
硝基苯氧胺。pH 值对重排产物产率的影响表明,瞬态螺梅森海默复合物可逆地形成。该物质的芳构化通过两种与 pH 无关的竞争性反应发生:一种涉及异羟
肟酸离子的排出;另一个涉及通过一般碱催化的复合物坍塌形成
氨基甲酸根离子。