Synthesis of 2-Aminobenzothiazoles via Nickel-Catalyzed Tandem Reaction of 2-Bromophenylisothiocyante with Amines

A tandem strategy for the synthesis of 2-aminobenzothiazoles from 2-bromophenylisothiocyanate and amines is reported. The reaction occurred efficiently in presence of Ni(acac)(2) as the catalyst precursor and ethanol as the solvent. A wide range of aliphatic amines including linear, branched, and cyclic primary and secondary amines proved potential substrates to construct diverse 2-aminobenzothiazole derivatives in good yields. The reaction is thought to proceed via the formation of a thiourea intermediate and a sequential nickel-catalyzed C-S bond formation.