Kinetics and Mechanism of the Base-Catalyzed Rearrangement and Hydrolysis of Ezetimibe
作者:Jana Baťová、Aleš Imramovský、Josef HájÍček、Ludmila Hejtmánková、Jiří Hanusek
DOI:10.1002/jps.24070
日期:2014.8
The pH-rate profile of the pseudo-first-order rate constants for the rearrangement and hydrolysis of Ezetimibe giving (2R,3R,6S)-N,6-bis(4-fluorophenyl)-2-(4-hydroxyphenyl)-3,4,5,6-tetrahydro-2H-pyran-3-carboxamide (2) as the main product at pH of less than 12.5 and the mixture of 2 and 5-(4-fluorophenyl)-5-hydroxy-2-[(4-fluorophenylamino)-(4-hydroxyphenyl)methyl]-pentanoic acid (3) at pH of more than
依泽替米贝重排和水解的拟一级反应速率常数的pH速率分布,得到(2R,3R,6S)-N,6-双(4-氟苯基)-2-(4-羟基苯基)-3主要产物,4,5,6-四氢-2H-吡喃-3-羧酰胺(2)在pH小于12.5以及2和5-(4-氟苯基)-5-羟基-2- [ pH值大于12.5的叔胺水溶液和氢氧化钠溶液中离子强度I = 0.1 mol L(-1)(KCl)的(4-氟苯基氨基)-(4-羟基苯基)甲基]-戊酸(3)并在39°C为报道。没有观察到缓冲液催化作用,仅涉及特定的碱催化作用。对于简单的β-内酰胺的水解,pH速率分布比pH速率分布更复杂,并且包含多个断裂点。在pH达到9时,log k(obs)随pH线性增加,但在pH 9和11之间会发生明显的分解,并且log k(obs)的值会随着培养基pH的升高而略有下降。在大约13的pH值下,发生另一个向上的断裂,这对应于化合物3的形成,该化合物缓慢转化为