Imidazobenzothiazine and primidobenzothiazine derivatives synthesis via an aliphatic SN2 substitution/Cu(I) catalyzed Ullmann coupling cascade process

An efficient method for the preparation of various imidazobenzothiazine and primidobenzothiazine derivatives from readily available 2-mercaptoimidazoles (thiouracils) and bromobenzyl bromides via a copper(I)-catalyzed one-pot cascade process has been developed. The reaction involves a SN2 process and an intramolecular C–N cross coupling cyclization.