Synthesis and reactions of 1-(4-bromo-, 4-fluoro-, and 4-trifluoromethylphenyl)-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles

Article abstract of DOI:10.1007/BF02291647

From 2-formyldimedone and 4-bromo-, 4-fluoro-, and 4-trifluoromethylphenylhydrazines we have obtained the corresponding 2-arylhydrazinomethylenedimedones, which in acid medium undergo ring closure to form 1-substituted 6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles. Oxidation of the latter by selenous acid leads to the corresponding 4,5-dioxo-4,5,6,7-tetrahydroindazoles, which then were converted to derivatives of 4,5-dihydro-3H-pyrazolo[4,3-a]phenazine and 4,5-dihydro-1H(3H)-indazolo[4,5-d]imidazole. 1998 Plenum Publishing Corporation.