REACTIONS OF CARBODIIMIDES .2. REACTIONS OF DICYCLOHEXYLCARBODIIMIDE WITH CARBOXYLIC ACIDS IN PRESENCE OF AMINES AND PHENOLS
REACTIONS OF CARBODIIMIDES .2. REACTIONS OF DICYCLOHEXYLCARBODIIMIDE WITH CARBOXYLIC ACIDS IN PRESENCE OF AMINES AND PHENOLS
复制标题
DOI：
10.1021/ja00957a028
复制
发表时间：
1966-01-01
影响因子：
15
通讯作者：
SILVERST.R
中科院分区：
文献类型：
--
作者：
DETAR, DF;SILVERST.R
对DCC与乙酸在三乙胺、吡啶、苄胺和对硝基苯酚存在下在乙腈和四氯化碳中反应的产物进行了定量研究。考虑到非质子介质中酸碱混合物中存在的几种离子对和其他复杂物质，可以定性地解释这些结果。第一部分报道的与乙酸二聚体的快速反应和与乙酸三乙胺的强减速效应都与酸A与碱b反应时组成物A2B的强络合物形成倾向有关。证据表明，酰基异脲是对硝基苯乙酸酯和n -苯乙酰胺形成的酰基化剂之一。乙酸酐与/>硝基苯醋酸酯一起形成，并负责/>硝基酚的部分乙酰化。与三乙胺相比，吡啶能提高乙酸酐的产率。它也导致对硝基苯乙酸酯的产量增加，但n -苯乙酰胺的产量没有增加。
Quantitative product studies have been made of the reactions of DCC with acetic acid in the presence of triethylamine, pyridine, benzylamine, and p-nitrophenol in acetonitrile and in carbon tetrachloride. The results can be explained qualitatively by considering the several ion pair and other complex species present in mixtures of acids and bases in aprotic media. Both the fast reaction with acetic acid dimer reported in part I and the strong deceler-ating effect observed with triethylammonium acetate can be correlated with the strong tendency to form complexes of the composition A2B when an acid A reacts with a base B. Evidence is presented that the acylisourea is one of the acylating agents in the formation of both p-nitrophenyl acetate and of N-benzylacetamide. Acetic anhydride is formed along with/> nitrophenyl acetate and is responsible for part of the acetylation of/> nitrophenol. In contrast to triethylamine, pyridine causes increased yields of acetic anhydride. It also leads to increased yields of p-nitro-phenyl acetate but not of N-benzylacetamide.