Amidines. IV. Hydrolysis of N1-acyl derivatives of N1,N2-diarylamidine in carboxylate buffer solution.
作者:Machiko ONO、Kazuhide HAYAKAWA、Shinzo TAMURA
DOI:10.1248/cpb.38.1176
日期:——
In the hydrolysis of N1-benzoyl-N1, N2-diphenylacetamidine (1) in carboxylate buffer solutions, nucleophilic attack of the catalytic acid was proved to take place at the amide carbonyl carbon (pathway d) and presumably also at the amidine central carbon (pathway e) in parallel to the normal hydrolysis processes. Mixed acid anhydride and N1, N2-diphenylacetamidine were formed by pathway d, and the former reacted with aniline formed by further hydrolysis of the latter to give two N-acylanilines. In parallel with this process, the mixed anhydride reacts with water to give two carboxylic acids. In this case, carboxylic acid acts as a nucleophilic catalyst.The reaction of 1 and p-methoxybenzoic acid under anhydrous conditions gave products derived from the attack of p-methoxybenzoate ion at both amide carbonyl and amidine central carbons.Hydrolysis of N1-benzoyl-N-1, N2-diphenylformamidine (7) in acetate buffer solution proceeded mainly through the ordinary hydrolysis pathway. Formation of a small amount of acetanilide implies that the reaction proceeds through pathway d or e to a small extent.In hydrolysis of N1-tosyl-N1, N2-di(p-methylphenyl)acetamidine (6b) in glycolate buffer solution, a small amount of N-(acetoxyacetyl)-p-toluidine was formed together with the ordinary hydrolysis products. This implies that the reaction proceeds through pathway e to a small extent.
在N1-苯甲酰-N1, N2-二苯基乙酰胺(1)在羧酸盐缓冲溶液中的水解过程中,催化酸的亲核攻击被证明发生在酰胺羰基碳(路径d),并且推测同时也在氨基中央碳上发生(路径e),与常规水解过程并行。通过路径d形成了混合酸酐和N1, N2-二苯基乙酰胺,而前者与通过对后者的进一步水解生成的苯胺反应,生成两个N-酰氨基苯。他们同时,混合酸酐与水反应,生成两个羧酸。在这种情况下,羧酸作为亲核催化剂。N1-苯甲酰-N-1, N2-二苯基甲酰胺(7)在醋酸盐缓冲液中的水解主要通过普通水解路径进行。少量乙酰苯胺的形成意味着反应在一定程度上通过路径d或e进行。在N1-对甲苯磺酰-N1, N2-二(对甲基苯基)乙酰胺(6b)在乙二醇酸盐缓冲液中的水解过程中,除了普通水解产物外,还形成了少量N-(乙酰氧乙酰)-对甲基苯胺。这意味着反应在一定程度上通过路径e进行。