This study comprises a brief literature survey on the chemistry and biological activity of the bridgehead nitrogen thiazolopyrimidines. In addition to, the synthesis of certain new substituted and fused thiazolopyrimidines, some of these compounds were subjected to preliminary screening for their antimicrobial activity.The structural elucidation of the new compounds was supported by elemental analyses, IR, 1H-NMR, in addition to mass spectrometry on demand. Some of the new compounds were subjected to preliminary antimicrobial testing and the data obtained are summarized.