A simple and efficient method for the synthesis of α-ketothioamides via the Willgerodt–Kindlerreaction is developed. Reactions were carried out between arylglyoxal hydrates, amines and elemental sulfur in water at 80°C to afford corresponding α-ketothioamides in good to high yields in a short reaction time.
A simple and efficient oxidative coupling of aromatic alkynes with elemental sulphur and secondary amines has been reported. The iodine/DMSO system easily promoted the transformations, affording thioglyoxamides via C–S, C–O, and C–N bond formations. In this context, acetylenic C–H bondoxidation has occurred through iodination, leading to the desired products. Moreover, this metal-free, one-pot protocol
Willgerodt-Kindler reaction of arylglyoxal hydrates with secondary amines and elemental sulfur under solvent-free conditions at 80 degrees C is developed, in which alpha-ketothioamides are obtained in 70-90% yield in 0.6-1 hour. The X-ray crystal-structure analysis for one compound was obtained.