title: Synthesis and electrophilic substitutions of novel pyrazolo[1,5-c]-1,2,4-triazolo[4,3-a]pyrimidines.
abstract: 5-Aryl-7-hydrazino-2-phenylpyrazolo[1,5-c]pyrimidines 1 were used as precursors for the preparation of a new series of 5-aryl-8-phenylpyrazolo[1,5-c]-1,2,4- triazolo[4,3-a]pyrimidines 2. The reactions of 2 with certain electrophilic reagents gave the respective 6-substituted derivatives 3-5 rather than the 7-isomeric products. Formylation of the key compounds 1 with ethyl formate yielded the formyl derivatives 6. Furthermore, boiling of compounds 1 with acetic acid afforded 7-acetylhydrazino-5-aryl-2-phenylpyrazolo[1,5-c]pyrimidines 7. Bromination of 7 yielded the dibromo- derivatives 8, while their iodination and nitration gave the monosubstituted derivatives 9 and 10, respectively. Also, treatment of 1 with boiling acetic anhydride yielded the triacetyl derivatives 11. The structure of synthesized products was confirmed by elemental analyses, IR, 1H NMR and MS spectra.
authors.affiliation: Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia P.O. Box 426, Alexandria 21321, Egypt. prof.kf_atta@yahoo.com
authors.forename: Kamal F M
authors.initials: KF
authors.lastname: Atta
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D005658:Fungi / Q000187:drug effects / Q000254:growth & development; D006219:Halogens / Q000737:chemistry; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009181:Mycoses / Q000188:drug therapy / Q000382:microbiology; D011720:Pyrazoles / Q000737:chemistry*; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000494:pharmacology; D014230:Triazoles / Q000737:chemistry*
chemical_list: D000935:Antifungal Agents; D006219:Halogens; D011720:Pyrazoles; D011743:Pyrimidines; D014230:Triazoles; D019342:Acetic Acid