1990 年 38 巻 5 号 p. 1379-1388
N1-Tosyl-N1, N2-diarylacetamidines (1) undergo uncleophilic attack of N-tosylamide anion at the amidine central carbon, and the less basic N-tosylamido group is expelled from the intermediate, resulting in an amide exchange reaction. Reaction of 1 and N-arylcarboxamide afforded N1-acyl-N1, N2-diarylacetamidine (2). N1-(p-Chlorobenzoyl)-N1-(p-methoxyphenyl)-N2-(p-chlorophenyl)acetamidine (2a) could not be obtained as such, but was obtained as an equilibrium mixture of 2a and N1-(p-chlorobenzoyl)-N1-(p-chlorophenyl)-N2-(p-methoxyphenyl)acetamidine (2a') owing to rapid 1, 3-N, N-acylotropic rearrangement.N1-Acyl derivatives of unsymmetrical N1, N2-disubstituted formamidines could be isolated as such, showing that 1, 3-N, N-acyl migration takes place more slowly in the acylated formamidine system. An acyl derivative of formamidine in which the acyl group is attached at the less basic nitrogen of amidine underwent 1, 3-N.N-acyl migration to give another acyl derivative at elevated temperature.Reaction of N1-tosyl-N1-(p-nitrophenyl)-N2-(m-nitrophenyl)acetamidine (1h) and N-acylarylamines gave N1-acyl-N1-aryl-N2-(m-nitrophenyl)acetamidines (2) which underwent alcoholysis to give carboxylic acid ester and N1-aryl-N2-(m-nitrophenyl)acetamidines (3) at room temperature, and the latter was hydrolyzed to give arylamines and N-acetyl-m-nitroaniline on heating in aqueous tetrahydrofuran solution in the presence of acetic acid. Thus, the alcoholysis of N-acylarylamines was achieved under mild conditions.
