Benzothiazolo[3,2-a]pyrimidines and benzothiazolo[3,2-a]purines: synthesis and bioactivity prediction

An efficient strategy for the synthesis of benzothiazolo[3,2-a]pyrimidine and benzothiazolopurine derivatives was developed. The synthesis of benzothiazolopyrimidines involves cyclization of 2-aminobenzothiazole with bis(trichlorophenyl) malonate, nitration, chlorodeoxygenation, and reaction of the chlorinated derivative with secondary amines. Benzimidazolopyrimidines were transformed to benzo[4,5]thiazolo[3,2-a]purines by one-pot reduction of the nitro group followed by imidazole ring closure. The synthesized compounds were characterized by physicochemical analysis methods: IR and NMR spectroscopy, mass spectrometry, and elemental analysis. Molecular docking revealed promising compounds having an effect on influenza virus targets. The ligands have the highest calculated affinity for the “active” center of hemagglutinin, endonuclease, and PB2 protein of the RNA-dependent RNA polymerase.