One-pot and Three Component Coupling Synthesis of Novel para-((Benzothiazolylamino)(aryl/heteroaryl)methyl)-phenols and its Corresponding O-Tosylates under Catalyst- and Solvent-Free Conditions

A catalyst- and solvent-free procedure has been developed for the synthesis of para-(( Benzothiazolylamino)(aryl/heteroaryl)methyl)-functionalized phenols and its O-tosylates via one-pot three component coupling reaction of thymol or carvacrol, aryl/heteroaryl aldehydes, and 2-aminobenzothiazoles with high selectivity. The present amino methylation process is convenient to perform even on large scale with a broad scope. The products were likely formed through the initial para-attack of thymol on aldehydes to generate para-quinone methide intermediate and subsequent 1,6-Aza-Michael addition of 2-aminobenzothiazoles on in-situ generated para-quinone methide intermediate.