The Influence of Solvents and the Effect of Amine Salts upon the Reaction of N-Silylamines with N-Cyanoamino Compounds

Abstract

The conditions, of the reaction of N-silylamines with N-cyanoamino compounds were investigated in detail. Solvents containing no oxygen or nitrogen atoms were found to be preferable. For example, the reaction of N-butyl-N'-cyano-S-methylisothiourea [2 a] with N-(trimethylsilyl)diethylamine [1 a] afforded 73~75% of the corresponding guanidine derivative [3 a] in diehloromethane, whereas only 42~49% in dioxane, acetone or acetonitrile under the same conditions. In the presence of amine salts, especially pyridine nitrate, the reaction was remarkably accelerated. Thus the reaction of [2 a] with N-(trimethylsilyl)isopropylamine [1 b], N-phenyl-N'-cyano-S-methylisothiourea [2 b] with N-(trimethylsilyl)aniline [1 c], N, N'-dimethyl-N'-cyano-S-methyliso thiourea [2 c] with [1 b] and dimethyl cyanoimidodithiocarbonate [4] with [1 a] proceeded successfully in the presence of equimolar amounts of pyridine nitrate. © 1987, The Chemical Society of Japan. All rights reserved.