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Journal of the Korean Chemical Society (JKCS)

ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 33, Number 1
JKCSEZ 33(1)
February 20, 1989 

 
Title
The Kinetics and Mechanism of Hydrolysis of Styrylphenylsulfone Derivatives

Styrylphenylsulfone 유도체의 가수분해 반응 메카니즘
Author
Nack-Do Sung, Ki-Sung Kwon, Tae-Rin Kim

성낙도, 권기성, 김태린
Keywords
Abstract
pH 0.0∼14.00 범위에서 styrylphenylsulfone 유도체들의 가수분해반응에 대한 반응속도론적 연구가 25℃의 50% 메탄올-물속에서 자외선 분광법으로 이루어졌다. 반응속도식과 치환기 효과(ρ=1.85(pH 7.0), ρ=1(pH 13.0))로부터, pH 11.0이상에서는 전형적인 Michael형의 친핵성 첨가반응, pH 9.0이하에서는 물분자에 의한 일반 염기촉매반응, 그리고 pH 9.0∼11.0사이에서는 이들 두 반응이 경쟁적으로 일어남을 제안하였다.

The Kinetics of hydrolysis of styrylphenylsulfone derivatives in 50% methanol-water at 25℃ and ionic strength of 0.10 was investigated by UV spectrophotometry in the pH range of 0.0-14.0. The rate equations, which can be applied over a wide pH range, were obtained. The Hammett rho constants for the hydrolysis are 1.85 at pH 7.0 and 1.54 at pH 13.0, respectively. On the basis of the evidence, it is proposed that the general base-catalysis occurs in the hydrolysis of styrylphenylsulfone derivatives; above pH 11.0, Michael type nucleophilic addition take place, while below pH 9.0, the reaction is initiated by addition of water and from pH 9.0 to pH 11.0 these two reactions occur competitively.

Page
120 - 126
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