New One-Pot Synthesis of 1,3,5-Triazines: Three-Component Condensation, Dimroth Rearrangement, and Dehydrogenative Aromatization

A new, effective one-pot synthesis
of the 6,N2-diaryl-1,3,5-triazine-2,4-diamines
under microwave irradiation
was developed. The method involved an initial three-component condensation
of cyanoguanidine, aromatic aldehydes, and arylamines in the presence
of hydrochloric acid. Without isolation, the resulting 1,6-diaryl-1,6-dihydro-1,3,5-triazine-2,4-diamines
were treated with a base to initiate Dimroth rearrangement and spontaneous
dehydrogenative aromatization, affording the desired compounds. The
developed method was found to be sufficiently general in scope, tolerating
various aromatic aldehydes and amines; by using their combinations
in the first step, a representative library of 110 compounds was successfully
prepared and screened for anticancer properties.