Pyrazolo[1,5-f]phenanthridine and derivatives: electrochemical and photochemical synthesis
Abstract
5-(2-Chlorophenyl)-1-phenylpyrazole affords a good yield of pyrazolo[1,5-f]phenanthridine on electroreduction in dimethylformamide and on irradiation in cyclohexane at 254 nm. 2-Methyl-, 2-phenyl-, and 5,6-methylene-dioxy-2-phenyl-pyrazolo[1,5-f]phenanthridine were also prepared from the appropriately substituted pyrazoles. 5-(2-Bromophenyl)-1,3-diphenylpyrazole also undergoes these reactions. Pyrazolo[1,5-f]phenanthridine and its derivatives form charge-transfer complexes with 1,3,5-trinitrobenzene and with picric acid.