Indazole 3- chloro-2-phenyl

Chloro-2-methyl-4-phenylquinazoline 1-oxide gives l-acetyl-5-chloro-3-phenyl-l//-indazole on irradiation. This transformation is believed to proceed by rearrangement of the oxaziridines formed as primary isomerization products. ... 

The reverse of the above transformation, i.e., conversion of a quinazoline into an indazole, has been observed. Thus photolysis of 6-chloro-2-methyl-4-phenylquinazoline 1-oxide provided l-acetyl-5-chloro-3-phenylindazole, and most probably proceeded via 7-chloro-2-methyl-5-phenyl-3,l,4-benzo-oxadiazepine because the latter yields the same indazole on photolysis. ... 

Chloro-l-methyl-3-phenylindazole 2-oxide refluxed 2 days with acetic anhydride l-acetoxymethyl-5-chloro-3-phenyl-lH-indazole. Y 65%. G. S. Zen-choff, A. Walser, and R. I. Fryer, J. Heterocyclic Chem. 13, 33 (1976). 

Similarly, addition of methylene chloride solutions of 26a—c to DDQ (6) in the same solvent gave 157 (6-11%), together with 3-amino-5,6-di-chloro-4,7-dioxo-N-phenyl-4H-indazole-2(7JJ)-carbothioamide (159, 71%) (Scheme 51,07ARK265). 

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