Synthesis and anti-cancer activity of pyridine and thiazolopyrimidine derivatives using 1-ethylpiperidone as a synthon

Abstract

213-2213,5-Bisarylmethylene-1-ethylpiperidone 2 on reaction with thiourea yield the thioxopyri midine derivatives 3, which on condensation with bromoacetic acid, 2-bromopropanoic acid or 3-bromopropanoic acid afford thiazolopyrimidine 4, 2-methyl-thiazolopyrimidines 5 and thiazinopyrimidine derivatives 6, respectively. Compounds 7 and 8 are also obtained via condensation of compounds 3 with 3-chloropentan-2, 4-dione, bromoacetic acid and aromatic aldehydes, respectively. However, compounds 8 are prepared directly by condensation of compounds 4 with aromatic aldehydes. Compounds 2 on condensation with malononitrile in ethanol/piperidine or acetic acid/ammonium acetate mixture give pyridopyran 9 and pyridopyridine 10, respectively. Also compound 10 could be prepared directly from compound 9. Compounds 2 when condensed with phenylhydrazine, ethyl cyanoacetate or guanidine hydrochloride yields pyridopyrazole 11, pyridopyridone 12 and pyridoaminopyrimidine derivatives 13, respectively