The kinetics of hydrolysis at medium acid strength (pH interval 2–5) of a series of phenylsulfamate esters 1 have been studied and they have been found to react by an associative S_N2(S) mechanism with water acting as a nucleophile attacking at sulfur, cleaving the S–O bond with simultaneous formation of a new S–O bond to the oxygen of a water molecule leading to sulfamic acid and phenol as products. In neutral to moderate alkaline solution (pH ≥ ∼ 6–9) a dissociative (E1cB) route is followed that involves i) ionization of the amino group followed by ii) unimolecular expulsion of the leaving group from the ionized ester to give N-sulfonylamine [HNSO₂] as an intermediate. In more alkaline solution further ionization of the conjugate base of the ester occurs to give a dianionic species which expels the aryloxide leaving group to yield the novel N-sulfonylamine anion [⁻NSO₂]; in a final step, rapid attack of hydroxide ion or a water molecule on it leads again to sulfamic acid. A series of substituted benzyl 4-nitrophenylsulfamate esters 4 were hydrolysed in the pH range 6.4–14, giving rise to a Hammett relationship whose reaction constant is shown to be consistent with the E1cB mechanism.

中文翻译：

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苯基和苄基4-硝基苯基氨基磺酸酯的水解机理†

研究了一系列苯氨基磺酸酯1在中等酸强度（pH区间2-5）下的水解动力学，发现它们通过缔合S _N 2（S）机理与水 充当亲核试剂攻击硫，裂解S–O键，同时与a的氧形成新的S–O键 水 分子导致 氨基磺酸 和 苯酚作为产品。在中性至中度碱性溶液（pH≥〜6–9）中，遵循解离（E1cB）途径，其中包括：i）氨基电离，然后ii）从电离酯中单分子驱离离去基团，得到N-磺胺[HN SO ₂ ]作为中间体。在更碱性溶液中的酯的共轭碱的进一步电离发生以得到排出的芳基氧化物的离去基团，得到新颖的双阴离子物种Ñ -sulfonylamine阴离子[ ^- Ñ SO ₂ ]; 在最后一步中，氢氧根离子或氢氧根离子的快速侵蚀水 分子再次导致 氨基磺酸。在6.4–14的pH范围内水解了一系列取代的4-硝基苯基氨基磺酸苄酯4，形成了Hammett关系，该关系的反应常数与E1cB机理一致。