Convenient synthesis of some new pyrazolo[1,5‐a]pyrimidine, pyridine, thieno[2,3‐b]pyridine, and isoxazolo[3,4‐d]pyridazine derivatives containing benzofuran moiety

Abstract magnified image Pyrazolo[1,5‐a]pyrimidines, pyrazoles, and thieno[2,3‐b]pyridine were synthesized from sodium salt of 5‐benzofuran‐2‐yl‐3‐hydroxypropenone and the appropriate of heterocyclic amines, diazonium chloride, and 1,3‐dicarbonoyl compounds. Pyrimidino[4′,5′:4,5]thieno[2,3‐b]pyridine, 1,2,3,4‐tetrazolo[1″,5″:6′,1′]‐pyrimidino[4′,5′:4,5]thieno[2,3‐b]pyridine and pyridino[2″,3″:2′,3′]thieno[4,5‐d]1,2,4‐triazolo[4,3‐e]pyrimidine derivatives were synthesized from 6‐benzo[d]furan‐2‐yl‐2‐thioxohydropyridine‐3‐carbonitrile and each of formic acid or formamide. Structures of the newly synthesized were established by elemental analysis and spectral data. J. Heterocyclic Chem. (2009).