Studies of Nitriles. X. Synthesis and Reactions of 2-Acylamino-3, 3-bis-(substituted mercapto) acrylonitriles and Their Derivatives. A New Synthesis of 2-Substituted-5-(substituted mercapto) oxazole-4-carbonitriles and Their Derivatives

Abstract

The reaction of 2-acylamino-3, 3-dichloroacrylonitriles (1) with various mercaptans in the presence of base gives 2-acylamino-3, 3-bis (substituted mercapto) acrylonitriles (5) or 2-acylamino-3-chloro-3-(substituted mercapto) acrylonitriles (17), each in good yield, depending upon the amount of mercaptans used. Similar nucleophilic substitutions are possible with the corresponding amides (8, 9), N-acylamides (10), esters (7), and acid (11). Treating the 3-mercapto acrylic acid derivatives thus obtained with silver compounds, such as Ag₂O, Ag₂CO₃, and CH₃COOAg, gives an excellent new method for synthesizing 5-(substituted mercapto) oxazoles (4). The scope and limitations of this new cyclization are also described.