SYNTHESIS AND REACTIONS OF SOME PYRIDINE AND THIENO [2,3-b] PYRIDINE DERIVATIVES WITH EXPECTED BIOLOGICAL ACTIVITY

Abstract

A synthesis of pyridine-2(1H)-thione derivative 2 and thieno-[2,3-b] -pyridine derivatives 4,5 utilizing cyanothioacetamide and arylhydrazone of benzoylacetone 1 as starting compounds is described. Pyridinethione derivative 6 reacted with aromatic aldehyde to give styrylpyridinethione derivative 7. Compound 7 was reacted with chloroacetone to obtain thienopyridine derivative 8. Cycloaddition reaction was carried out on 8 with dienophiles, to afford the corresponding cycloadduct 9.Pyridinethione derivative 6 reacted with halogen-containing materials to give the corresponding thienopyridine derivatives 10, 17. the reaction of 10 with triethyl orthoformate or formic acid led to the formation of pyridothienopyrimdine derivative 11. The hydrazino derivative 13, gave with triethyl orthoformate triazolo-pyrimidothienopyridine derivative 14. Compound 10 reacted with nitrous acid to gave pyridothienotrizinone derivative 15. Thienopyridine derivative 17 reacted with triethyl orthoformate to give 18. Triazipinopyrimidothienopyridine derivative 20 obtained from compound 18 after reaction with hydrazine hydrate and acetylacetone. Compound 17 reacted with carbon disulfide to give pyrimidinedithione derivative 21.