First Determination of the Absolute Configuration of an Atropisomeric Flavin Derivative

The crystal structure and absolute configuration of the (-)-enantiomer of 3-(4,6-dibromo-2-methylphenyl)-10-(4-tert-butylphenyl)pyrimido[4,5-b]quinoline-2,4(3H,10H)-dione methanol solvate, C₂₈H₂₃Br₂N₃O₂.CH₄O, have been determined. The absolute configuration is S. The asymmetric unit contains two crystallographically independent molecules which are related by a pseudo inversion center.

-1