Synthesis of Some Benzofuranyl Thieno[2,3-D] Pyrimidine Derivatives With Biological Interest

Abstract

Interaction of visnaginone or khellinone (1a,b) with cyanoacetamide, ethyl cyanoacetate or molanonitrile and elemental sulfur in presence of triethylamine afforded thiophene enamino derivatives (2a-d) respectively according to Gewald method. Acetylation of 2a with acetic anhydride gave 3. Condensation of 2b with p-chlorobenzaldehyde yielded 4. Compound 6 was afforded from reaction of enamino carboxamide (2b) with thiourea.. Compound 2b reacted with benzoyl chloride to give thienopyrimidine (8). N-phenyl thienopyrimidine (11) and N-amino thienopyrimidine (13) were prepared from reaction of 2c with phenyl isothiocyanate and hydrazinolysis of 12 with hydrazine hydrate.The structures of these compounds were confirmed by infrared, mass and 1 H-NMR spectra. The biological activity of some compounds were discussed and found to be active.On the other hand, thienopyridines possess remarkable activity against Herpes simplex virus type 1 (HSV-1) (14)(15)(16)(17)(18) . Results and DiscussionAccording to Gewald method (19) thiophene enamino derivatives (2a-d) were obtained from the reaction of 5-[4-methoxy (4,7-dimethoxy)-6 hydroxy 125