Abstract |
다음과 같은 새로운 4종의 N-(arylsulfonyl)benzamide 유도체와 6종의 N-(arylsulfonyl)benzimidothiophenyl ester 유도체를 합성하였다. m-methyl-N-(arylsulfonyl)benzamide, p-methyl-N-(arylsulfonyl)benzamide, m-nitro-N-(arylsulfonyl)benzamide, p-methoxy-N-(arylsulfonyl)benzamide, p-methyl-N-(arylsulfonyl)benzimidothiophenyl esters, m-methyl-N-(arylsulfonyl)benzimidothiophenyl ester, p-methoxy-N-(arylsulfonyl)benzimidothiophenyl ester, p-nitro-N-(arylsulfonyl)benzimidothiophenyl ester, m-nitro-N-(arylsulfonyl)benzimidothiophenyl ester, p-chloro-N-(arylsulfonyl)benzimidothiophenyl ester. 넓은 pH 범위에서 N-(arylsulfonyl)benzimidothiophenyl esters 유도체의 가수분해속도 상수를 자외선 분광광도법으로 측정하여 넓은 pH 범위에 적용되는 반응속도식을 구하였다. 이 속도식과 치환기효과등으로부터 N-arylsulfonylbenzimidothiophenyl esters 유도체에 대한 가수분해 반응메카니즘을 제안하였다. 즉 pH 11 이상에서는 hydroxide ion이 pH 9 이하에서는 azomethine 기에 물분자가 첨가되므로서 반응이 시작되며 pH 9∼11 사이에서는 물분자와 hydroxide ion이 경쟁적으로 반응함을 알았다. Four unreported derivatives of N-arylsulfonylbenzamide and six derivatives of N-arylsulfonylbenzimidothiophenyl ester were prepared. These were; p-methyl-N-(arylsulfonyl)benzamide, m-methyl-N-(arylsulfonyl)benzamide, m-nitro-N-(arylsulfonyl)benzamide, p-methoxy-N-(arylsulfonyl)benzamide, p-methyl-N-(arylsulfonyl)benzimidothiophenyl esters, p-chloro-N-(arylsulfonyl)benzimidothiophenyl ester, m-methyl-N-(arylsulfonyl)benzimidothiophenyl ester, p-nitro-N-(arylsulfonyl)benzimidothiophenyl ester, m-nitro-(arylsulfonyl)benzimidothiophenyl ester and p-methoxy-N-(arylsulfonyl)benzimidothiophenyl ester. The rate constants of the hydrolysis of N-arylsulfonylbenzimidothiophenyl esters were determined by ultraviolet spectrophotometry at various pH and rate equations which can be applied over a wide pH range were obtained. From the rate equation and substituent effects, one can conclude that above pH 11, the hydrolysis of N-arylsulfonylbenzimidothiophenyl esters are initiated by the attack of hydroxide ion, however, below pH 9, started by the addition of a water molecule on the azomethine group. At pH 9∼11, the competitive reaction between a water molecule and hydroxide ion is anticipated to occur. |
