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Updated: May 31, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Monoclinic polymorph of 2,5-bis[4-(dimethyl-amino)-styr-yl]-3,6-dimethyl-pyrazine
Janina Fischer1, Volker Schmitt, Dieter Schollmeyer
1University Mainz, Duesbergweg 10-14, 55099 Mainz, Germany.
Abstract:
The title compound, C(26)H(30)N(4), was prepared by condensation of tetra-methyl-pyrazine and dimethyl-amino-benzaldehyde and crystallizes from chloro-form/methanol in two different forms. Block-shaped crystals belong to the monoclinic crystal system and plates to the triclinic system. The two crystal forms differ in the arrangement of the centrosymmetric mol-ecules, which have nearly identical geometries. In the monoclinic crystals reported here, planar mol-ecules [maximum deviation = 0.062 (2) Å], with a transoid arrangement of the (E)-styryl units and completely planarized dimethylamino groups [sum of the C-N bond angles = 359.9 (2)°], form layers connected via H-π-stacking. The dihedral angle between the central and pendant rings is 1.30 (8)°. The triclinic polymorph contains two half molecules, both completed by crystallographic inversion symmetry.
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