Mild and efficient synthesis of benzothiazolopyrimidine derivatives via CuAAC/ring cleavage/cyclization reaction.

An operationally mild and efficient synthesis of benzothiazolopyrimidine is achieved by a three-component reaction of 2-aminebenzo[ d ]thiazoles, sulfonyl azides and terminal ynones. This cascade process involved a CuAAC/ring cleavage/cyclization reaction. Particularly, most of the benzothiazolopyrimidine derivatives could be isolated by filtration without further purification.