Next Article in Journal
Alkaloids from Hippeastrum papilio
Next Article in Special Issue
Synthesis and in Vitro Antimicrobial Activity of Some Pyrazolyl-1-carboxamide Derivatives
Previous Article in Journal
Activity and Stability Studies of Verbascoside, a Novel Antioxidant, in Dermo-Cosmetic and Pharmaceutical Topical Formulations
Previous Article in Special Issue
Synthesis and Contractile Activity of Substituted 1,2,3,4-Tetrahydroisoquinolines
Article Menu

Article Versions

Export Article

Open AccessArticle
Molecules 2011, 16(8), 7081-7096; doi:10.3390/molecules16087081

Synthesis and Electrophilic Substitutions of Novel Pyrazolo[1,5-c]-1,2,4-triazolo[4,3-a]pyrimidines

Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia P.O. Box 426, Alexandria 21321, Egypt
Received: 30 June 2011 / Revised: 1 August 2011 / Accepted: 4 August 2011 / Published: 18 August 2011
(This article belongs to the Special Issue Heterocycles)
Download PDF [454 KB, uploaded 18 June 2014]   |  

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.
Keywords: pyrazolo[1,5-c]-1,2,4-triazolo[4,3-a]pyrimidines; synthesis; electrophilic substitution reactions; dehydrative cyclization pyrazolo[1,5-c]-1,2,4-triazolo[4,3-a]pyrimidines; synthesis; electrophilic substitution reactions; dehydrative cyclization
Figures

This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Atta, K.F. Synthesis and Electrophilic Substitutions of Novel Pyrazolo[1,5-c]-1,2,4-triazolo[4,3-a]pyrimidines. Molecules 2011, 16, 7081-7096.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]

Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top