Synthesis of phenothiazines from cyclohexanones and 2-aminobenzenethiols under transition-metal-free conditions
A convenient method for the synthesis of various substituted phenothiazines from cyclohexanones and 2-aminobenzenethiols using molecular oxygen as hydrogen acceptor in the absence of transition-metals is described. For the first time cyclohexanones were used as coupling partners for the construction of phenothiazines.