Amidines. V. Smiles rearrangement of N1-(p-nitrobenzenesulfonyl)-N1,N2-diarylacetamidines.

Abstract

N 1 -Tosyl-N 1 ,N 2 -diarylacetamidine suffered nucleophilic attack of N-tosylamines and N-acylamines at the amidine central carbon to give N 1 -tosyl and N 1 -acyl derivatives of N 1 ,N 2 -disubstituted acetamidine in the presence of a basic catalyst. Preparation of N 1 -(p-nitrobenzenesulfonyl)-N 1 ,N 2 -diarylacetamidines was attempted to obtain better starting materials for the above amide exchange reaction. These compounds, however, proved to be unsuitable for the purpose because they readily underwent Smiles rearrangement to give N 1 -(p-nitrophenyl)-N 1 ,N 2 -diarylacetamidies with loss of sulfur dioxide. N 1 -(p-Nitrophenyl)-N 1 -(p-methylphenyl)N 2 -(p-chlorophenyl)acetamidine was formed when an ethanol solution of N 1 -(p-nitrobenzenesulfonyl)-N 1 -(p-chlorophenyl)-N 2 -(p-methylphenyl)acetamidine was refluxed for 2.5 h in the absence of any catalyst