Efficient routes to pyrazolo[3,4-e][1,2,4]triazines and a new ring system: [1,2,4]triazino[5,6-d][1,2,3]triazines

Hamad Mohamed Al-Matar; Khaled Dessouky Khalil; Doa'a Mohamed Al-Dorri; Mohamed Helmy Elnagdi

doi:10.3390/molecules15053302

Efficient routes to pyrazolo[3,4-e][1,2,4]triazines and a new ring system: [1,2,4]triazino[5,6-d][1,2,3]triazines

Molecules. 2010 May 4;15(5):3302-10. doi: 10.3390/molecules15053302.

Authors

Hamad Mohamed Al-Matar¹, Khaled Dessouky Khalil, Doa'a Mohamed Al-Dorri, Mohamed Helmy Elnagdi

Affiliation

¹ Chemistry Department, Faculty of Science, University of Kuwait, P.O. Box 5969, Safat 13060, Kuwait. h.almatar@ku.edu.kw

Abstract

Arylhydrazonomalononitriles 1a,b react with phenylhydrazine to yield amidrazones 2a,b that cyclize to give 2-aryl-5-phenylhydrazono-2,5-dihydro-[1,2,4]-triazine-6-carbonitriles 5a,b upon reaction with dimethylformamide dimethylacetal (DMFDMA). Refluxing 5a,b in glacial acetic acid resulted in the formation of the pyrazolo-1,2,4-triazines 6a,b. Compounds 6a,b were also formed upon treatment of 3-amino-4-phenylhydrazono-1-phenyl-2-pyrazolin-5-ones 7a,b with DMFDMA. Reacting these triazinyl arylhydrazononitriles 5a,b with hydroxylamine hydrochloride in ethanolic sodium acetate afforded amidrazones 8a,b that are readily cyclized in refluxing dimethylformamide into [1,2,4]triazino[1,2,3]triazines 10a,b.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cyclization
Nitriles / chemistry
Phenylhydrazines / chemistry
Pyrazolones / chemical synthesis*
Triazines / chemical synthesis*

Substances

Nitriles
Phenylhydrazines
Pyrazolones
Triazines
phenylhydrazine
1,2,4-triazine