The ring closure and rearrangement of 1-(2-amino)-benzoyl-1-methylhydrazones of β-dicarbonyl compounds: on the formation and crystal structure of 3a,9a-dihydro- -1,3,3a,9a-tetramethyl-4H-pyrazolo[3,4-b]quinolin-4-one

The conversion of 1-(2-amino)-benzoyl-1-methylhydrazones of β-dicarbonyl compounds into heterocyclic derivatives yielded in addition to the already known type of product $\text{2}$ further three novel pyrazole derivatives $\text{3}$, $\text{4}$ and $\text{5}$. The structures of these products have been established by chemical and spectroscopic (MS) methods. The crystal structure of $\text{5}$ has been determined by X-ray diffraction.