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.

Synthesis and antitumor evaluation of some new derivatives and fused heterocyclic compounds derived from thieno[2,3‐b]pyridine

“…Compound 1 , 3‐amino‐4‐methyl‐6‐phenylthieno[2,3‐ b ]pyridine‐2‐carbonitrile, was synthesized according to the reported procedure. Cyanoacetylation of compound 1 was carried out through its reaction with cyanoacetic acid and acetic anhydride to yield the respective N ‐substituted‐2‐cyanoacetamide 2 as shown in Scheme . The 1 H NMR spectrum displayed a singlet signal at δ 4.56 ppm integrated for two protons because of CH 2 CN protons.…”

“…3‐Amino‐4‐methyl‐6‐phenylthieno[2,3‐ b ]pyridine‐2‐carbonitrile ( 1 ), ( 11 ), ( 20a ), ( 20b ), and ( 32 ) were prepared by previously reported procedures. All other chemicals in this study were purchased.…”

Utility of thieno[2,3-b] pyridine derivatives in the synthesis of some condensed heterocyclic compounds with expected biological activity

“…The o-aminonitrile thienopyridine derivative 2 was synthesized through treatment of the pyridine thione derivative 1 with chloroacetonitrile in presence of sodium hydroxide [32]. "( Scheme 1)".…”

Synthesis and antitumor evaluation of some new derivatives and fused heterocyclic compounds derived from thieno[2,3‐b]pyridine: Part 2

“…Cyclocondensation reaction [11] of 3-amino-4-methyl-6phenyl thieno[2, 3-b]pyridine-2-carbonitrile 1 occurred upon its treatment with ammonium thiocyanate in boiling glacial acetic acid to yield the corresponding thiourea derivative 2 as shown in Scheme 1. Compound 2 was treated with diethyl malonate in the presence of butanol [12] to afford the respective thiobarbituric acid derivative 3.…”

“…Compound (1) was synthesized according to the published procedure, [11] while compounds (8), (10), (23), (26), and (37) were prepared according to our previously published procedures. [19] However, reagents (16a), [29] (16b), [30] and (20) [37] were prepared according to the reported methods.…”