Synthesis and antimicrobial activity of some new substituted pyrido[3′,2′:4,5]thieno[3,2-d]-pyrimidinone derivatives

• Published in: Russian journal of bioorganic chemistry Vol. 40; no. 3; pp. 308 - 313
• Main Authors: Fayed, Ahmed A., Amr, Abd El-Galil E., Al-Omar, Mohamed A., Mostafa, Elsayed E.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.05.2014
• Subjects: Biochemistry; Biomedical and Life Sciences; Biomedicine; Bioorganic Chemistry; Life Sciences; Organic Chemistry; thienopyrimidine; antimicrobial agents; semi- and thiosemicarbazides; oxazinone
• ISSN: 1068-1620; 1608-330X
• DOI: 10.1134/S1068162014030042

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(3 H )-one derivatives were synthesized as antimicrobial agents using 7-(2-chloro-6-ethoxypyridin-4-yl)-9-(2,4-dichlorophenyl)-2-methyl-4 H -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.