Molecules 2011, 16(12), 10387-10408; doi:10.3390/molecules161210387
Article

Synthesis and Antibacterial Activities of Novel 2,5-Diphenylindolo[2,3-e] Pyrazolo[1',5':3",4"]pyrimido[2",1"-c] [1,2,4]triazines

Kamal F.M. Atta* email, Omaima O.M. Farahat, Somaya M. Ghobashy and Mohamed G. Marei
Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia P.O. Box 426, Alexandria 21321, Egypt
* Author to whom correspondence should be addressed.
Received: 3 October 2011; in revised form: 2 November 2011 / Accepted: 16 November 2011 / Published: 15 December 2011
(This article belongs to the Special Issue Heterocycles)
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Abstract: The formation of (E)-3-{2-(2,5-diphenylpyrazolo[1,5-c]pyrimidin-7-yl)hydrazono}indolin-2-ones 3 has been achieved by condensation of equimolar amounts of 7-hydrazino-2,5-diphenylpyrazolo[1,5-c]pyrimidine (1) and isatin (or isatin derivatives) 2 at room temperature. The (E)-products could be isomerized into corresponding the (Z)-3 isomers. Reactions of the latter fused heterocyclic hydrazones towards different electro-philic reagents yielded the corresponding 3-substituted derivatives 4–7. Dehydrative cyclisation of the hydrazones 3 using phosphorus oxychloride afforded the 2,5-diphenyl- indolo[2,3-e]pyrazolo[1',5':3",4"]pyrimido[2",1"-c][1,2,4] triazines 13. The polyfused heterocyclic ring system 13 underwent electrophilic substitution reactions at position 4 rather than at position 3. The 3-bromo isomer of 17 was prepared by a sequence of reactions starting from 2,5-diphenylpyrazolo[1,5-c]pyrimidine-7(6H)-thione (11). The orientation of the electrophilic attack was supported by spectroscopic and chemical evidence. Some of the synthesized compounds were found to possess slight to moderate activity against the microorganisms Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa.
Keywords: pyrazolopyrimidine; isatin; hydrazone; indolopyrazolopyrimidotriazine; antibacterial activity

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MDPI and ACS Style

Atta, K.F.; Farahat, O.O.; Ghobashy, S.M.; Marei, M.G. Synthesis and Antibacterial Activities of Novel 2,5-Diphenylindolo[2,3-e] Pyrazolo[1',5':3",4"]pyrimido[2",1"-c] [1,2,4]triazines. Molecules 2011, 16, 10387-10408.

AMA Style

Atta KF, Farahat OO, Ghobashy SM, Marei MG. Synthesis and Antibacterial Activities of Novel 2,5-Diphenylindolo[2,3-e] Pyrazolo[1',5':3",4"]pyrimido[2",1"-c] [1,2,4]triazines. Molecules. 2011; 16(12):10387-10408.

Chicago/Turabian Style

Atta, Kamal F.M.; Farahat, Omaima O.M.; Ghobashy, Somaya M.; Marei, Mohamed G. 2011. "Synthesis and Antibacterial Activities of Novel 2,5-Diphenylindolo[2,3-e] Pyrazolo[1',5':3",4"]pyrimido[2",1"-c] [1,2,4]triazines." Molecules 16, no. 12: 10387-10408.

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