Kinetics and mechanism of the imidazole-catalysed hydrolysis of substitutedN-benzoylimidazoles
作者:Omar A. El Seoud、Paulo Menegheli、Paulo A. R. Pires、Nilo Z. Kiyan
DOI:10.1002/poc.610070807
日期:1994.8
Imidazole (Imz)-catalysed hydrolysis of benzoate esters proceeds via the intermediate formation of N-benzoylimidazoles. This paper considers the second step of this reaction, viz., Imz-catalysed hydrolysis of N-(4-X-benzoyl)imidazoles, X = CH3, H, Cl, CN and NO2, and N-(disubstituted benzoyl)imidazoles, 2-chloro-4-nitro, 2, 4-dinitro and 3,5-dinitro, in water–acetonitrile mixtures (10% or 14%, v/v
咪唑(Imz)催化的苯甲酸酯水解是通过中间形成N-苯并咪唑进行的。本文考虑了该反应的第二步,即,Imz催化的X = CH 3,H,Cl,CN和NO 2的N-(4-X-苯甲酰基)咪唑和N-(二取代的苯甲酰基)的水解水-乙腈混合物中的咪唑,2-氯-4-硝基,2,4-二硝基和3,5-二硝基(在有机溶剂中为10%或14%,v / v)。基于催化速率常数和动力学溶剂的同位素效应,表明Imz的催化是一般碱型的。出乎意料的是,水解ñ - (2,4-二硝基苯甲酰基)咪唑被发现是比的慢Ñ-(4-硝基苯甲酰基)咪唑。结果表明,这种反应顺序是由于空间效应和Imz部分与2,4-二硝基苯环之间的供体-受体相互作用所致的反应物状态稳定化的结合。