title: Synthesis, antibacterial activity and cytotoxicity of new fused pyrazolo[1,5-a]pyrimidine and pyrazolo[5,1-c][1,2,4]triazine derivatives from new 5-aminopyrazoles.
abstract: New 5-aminopyrazoles 2a-c were prepared in high yields from the reaction of known α,α-dicyanoketene-N,S-acetals 1a-c with hydrazine hydrate under reflux in ethanol. These compounds were utilized as intermediates to synthesize pyrazolo[1,5-a]-pyrimidines 3a-c, 4a-d, 5a-c, and 6a-c, as well as pyrazolo[5,1-c][1,2,4]triazines 7a-c and 8a-c, by the reaction of 2-[bis(methylthio)methylene]malononitrile, α,α-dicyanoketene-N,S-acetals 1a-b, acetylacetone, acetoacetanilide as well as acetylacetone, and malononitrile, respectively. Furthermore, cyclization of 2a-c with pentan-2,5-dione yielded the corresponding 5-pyrrolylpyrazoles 9a-c. Moreover, fusion of 2a-c with acetic anhydride resulted in the corresponding 1-acetyl-1H-pyrazoles 10a-c. The antibacterial activity and cytotoxicity against Vero cells of several selected compounds are also reported.
authors.affiliation: School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. we80dad@yahoo.com
authors.forename: Wedad M
authors.initials: WM
authors.lastname: Al-Adiwish
authors.forename: M I M
authors.initials: MI
authors.lastname: Tahir
authors.forename: A
authors.initials: A
authors.lastname: Siti-Noor-Adnalizawati
authors.forename: Siti Farah
authors.initials: SF
authors.lastname: Hashim
authors.forename: Nazlina
authors.initials: N
authors.lastname: Ibrahim
authors.forename: W A
authors.initials: WA
authors.lastname: Yaacob
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002522:Chlorocebus aethiops; D018360:Crystallography, X-Ray; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D015394:Molecular Structure; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D011743:Pyrimidines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014227:Triazines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D014709:Vero Cells
chemical_list: D000900:Anti-Bacterial Agents; D011720:Pyrazoles; D011743:Pyrimidines; D014227:Triazines; C527752:pyrazolo(1,5-a)pyrimidine