FACILITATED REVERSIBLE FORMATION OF AMIDES FROM CARBOXYLIC ACIDS IN AQUEOUS SOLUTIONS - INTERMEDIATE PRODUCTION OF ACID ANHYDRIDE
FACILITATED REVERSIBLE FORMATION OF AMIDES FROM CARBOXYLIC ACIDS IN AQUEOUS SOLUTIONS - INTERMEDIATE PRODUCTION OF ACID ANHYDRIDE
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DOI：
10.1021/ja00905a028
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发表时间：
1963-01-01
影响因子：
15
通讯作者：
HERD, AK
中科院分区：
文献类型：
--
作者：
HIGUCHI, T;MIKI, T;HERD, AK
羧基对某些酰胺酸的形成和水解的促进作用是由酸酐的形成介导的，这似乎是速率决定步骤。（1）琥珀酸转化为琥珀酸酐的pH-速率曲线，（2）逆反应的pH曲线，（3）独立测定的平衡常数的pH曲线都支持这一机理。在此基础上，在25 ℃下酸酐在水中的等锂浓度估计为25 ℃下2份/107，95 ℃下3份/106。据信柠檬酸、酒石酸和相关的二元和多元羧酸以类似的方式反应。
The facilitative roleof carboxylic grouping on formation and hydrolysis of certain amido acids is shown to be mediated by formation of acid anhydrides, which appears to be the rate-determining step. The mechanism is supported by (1) the pH-rate profileof conversion of succinic acid to succinic anhydride,(2) the pH profile of the reverse reaction, and (3) the independently determined pH profile of the equilibrium constant. The equi-librium concentration of the anhydride in water at 25 is estimated on this basis to be 2 parts per 107 at 25 and 3 parts per 106 at 95. Citric acid, tartaric acid, and related di-and polycarboxylic acids are believed to react in similar fashion.