Synthesis of 4(pyrazol-3-yl)[1,2,4]triazolo[4,3-a]quinoxalines and tetrazolo analog

Article abstract of DOI:10.1002/jhet.5570310250

The transformation of 2-chloro-3-[5-(acetoxymethyl)-1-phenylpyrazol-3-yl]quinoxaline 3 to 1-aryl-4-[5-(hydroxymethyl-1-phenylpyrazol-3-yl][1,2,4]triazolo[4,3-a] quinoxalines 4a-c has been achieved upon treatment with aroylhydrazines in boiling butanol. Compounds 4a-c were smoothly acetylated by acetic anhydride to give their acetyl derivatives 5a-c in good yield. 4-[5-(Acetoxymethyl)-1-phenylpyrazol-3-yl]1-methyl[ 1,2,4]triazolo[4,3-a]quinoxaline was prepared by ring closure of 2-hydrazine-3-[5-(hydroxymethyl)-1-phenylpyrazol-3-yl]quinoxaline 6 by the action of acetic anhydride. The reaction of 6 with acetylacetone afforded 3-[5-(hydroxymethyl)-1-phenylpyrazol-3-yl]-2-(3,5-dimethylpyrazol-1-yl )quinoxaline 8. In addition, the reaction of 3 with sodium, azide in boiling N,N-dimethylformamide yielded the fused tetrazolo[1,5-a]quinoxaline 9.