Synthesis, Anti-hepatitis B and C Virus Activity and Antitumor Screening of Novel Thiazolo[4,5-d]-pyrimidine Derivatives.

The paper describes the synthesis, antivirus and antitumor evaluation of novel thiazolo[4,5-d]pyrim- idine derivatives. The target compounds 3a-h were synthesized by cyclocondensation of 4-amino-N'-(phenyl- methylidene)-3-phenyl-2-thioxo-2,3-dihydrothiazole-5-carbohydrazides 2a-d with aromatic aldehydes. The structures of new compounds were determined by IR, ¹H-NMR and elemental analysis. Thiazolopyrimidines 3a and 3d-h were screened by the National Institute of Allergy and Infectious Diseases against various viruses. Four compounds 3e-h showed in vitro anti-HCV activity. One (3e) demonstrated significant activity against HBV and was submitted to an anti-HBV in vivo assay but had a low bioavailability. As a result of antitumor study, compound 3h was found to be most potent against leukemia SR.