Heterocycles of biological importance: Part 7. Synthesis of biologicallyactive pyrimido[2,1-b]benzothiazoles from acetylenic acids and2-aminobenzothiazoles

Abstract

Conjugate addition of the imino nitrogen of 2-aminobenzothiazoles 1 to the alkyne β-carbon atom of acetylenic acids 2 followed by ring closure gives rise to novel 2H-pyrimido[2,1-b]-benzothiazol-2-ones in good yield.