Willgerodt-Kindler Reaction of Benzaldehydes: A Comparative Study for a Sustainable Synthesis of Secondary Thiobenzamides
The synthesis of thiobenzamides from benzaldehydes, elemental
sulfur and cyclic secondary amines was carried out by
Willgerodt-Kindler reaction following three different protocols,
avoiding the harsh conditions usually reported in the literature.
Protocol A was solventless, protocol B was in acetonitrile, while
protocol C was electrochemical in acetonitrile (using electrogenerated
acetonitrile anion). For all protocols the temperature
was 60 8C. In all cases, a stoichiometric amount of reagents was