Synthesis and antimicrobial activity of some new substituted pyrido[3',2':4,5]thieno[3,2-d]-pyrimidinone derivatives
Fayed, A.A.; Amr, A.E.-G.E.; Al-Omar, M.A.; Mostafa, E.E.
Bioorganicheskaia Khimiia 40(3): 335-340
2014
ISSN/ISBN: 0132-3423 PMID: 25898741 Document Number: 678371
A series of new 3-substituted-7-(2-chloro-6-ethoxypyridin-4-yl)-9-(2,4-dichlorophenyl)-2-methylpyrido[3',2':4,5]thieno[3,2-d]pyrimidin-4(3H)-one derivatives were synthesized as antimicrobial agents using 7-(2-chloro-6-ethoxypyridin-4-yl)-9-(2,4-dichlorophenyl)-2-methyl-4H-pyrido[3',2':4,5]thieno[3,2-d]-[1,3]oxazin-4-one as a starting compound. Its condensation with substituted aniline derivatives or phenyl hydrazine gave the corresponding N-substituted derivatives. Treatment of the starting compound with hydrazine hydrate afforded the corresponding N-amino derivative, which was reacted with substituted phenylisocyanate and phenylisothiocyanate derivatives to give the corresponding semicarbazides and thiosemicarbazide derivatives. All the newly synthesized compounds were evaluated for their antimicrobial activities in comparison to streptomycin and fusidic acid as positive controls. The structure assignments of the new compounds are based on chemical and spectroscopic evidence.