|
KMID : 1059519940380050366
|
|
Journal of the Korean Chemical Society
1994 Volume.38 No. 5 p.366 ~ p.371
|
|
|
A Study on the Kinetics and Mechanism of the Hydrolysis of 5,6-Dihydro-1,4-thiazine Derivatives
|
|
Lee Kwang-Il
Lee Suck-Woo
Kwak Chun-Geun
Jang Byung-Man
Kim Young-Ju
Lee Gi-Chang
|
|
|
Abstract
|
|
|
|
The kinetics of the hydrolysis of 5,6-dihydro-1,4-thiazine derivatives was investigated by ultraviolet spectrophotometry in H2O at 25℃. A rate equation which can be applied over a wide pH range was obtained. The substituent effects on the hydrolysis of 5,6-dihydro-1,4-thiazine derivatives were studied and the rate of hydrolysis was shown to be accelerated by electron donating groups. Final product of the hydrolysis was 2-(N-acetylaminoethylthio)-acetoacetanilide enol from Judging from the results of the rate equation, general base effect, activation parameters and final products, the hydrolysis of 5,6-dihydro-1,4-thiazine derivatives seemed to be initiated by the neutral H2O molecule which does not dissociate at pH below 10.0, but proceeded by the hydroxide ion at pH above 11.0, and those two reactions occurred competively at pH 10.0∼11.0 range. On the basis of these findings a plausible mechanism for the hydrolysis of 5,6-dihydro-1,4-thiazine derivative was proposed.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|