Crystal Structure of 8,9-Dimethoxy-5,5-dimethyl-2,3,5,6-tetrahydro-3- oxopyrazolo[3,4-b]benzo-3-azepine

The crystal structure of 8,9-dimethoxy-5,5-dimethyl-2,3,5,6-tetrahydro-3- oxopyrazolo[3,4-b]benzo-3-azepine is determined by X-ray diffraction analysis. The molecule crystallizes in the form of an isomer with the hydrogen atom at the nitrogen atom in position 2 of the pyrazolone fragment. The electron density is localized over the multiple bonds N(1)=C(12) (1.253(5) Å) of the azepine cycle and N(2)=C(1) (1.302(4) Å) of the pyrazolone cycle.