Unique 11b‐Substituted Indeno[2,1‐c]quinolin‐6‐one Ring System

Abstract

A unique 11b‐substituted indeno[2,1‐c]quinolin‐6‐one ring system was prepared in good yield and the structure of the product was unequivocally determined by X‐ray crystallography.

Keywords:

• Indenoquinolone
• X-ray
• crystal structure

Notes

^†This product was cleanly obtained as a pale yellow precipitate after the crude reaction mixture had been poured onto ice.

^‡For a single crystal (0.40×0.25×0.25 mm³) of 2 (racemate), grown from ethyl acetate/methanol, X‐ray intensity data were collected at 299 K on a Bruker‐AXS APEX diffractometer. A total of 3526 independent reflections were observed. Laue symmetry revealed a triclinic crystal system with unit cell dimensions: a=6.6089(10), b=8.5087(13), c=15.193(2) A° and angles α=98.289(3)°, β=101.993(3)°, γ=107.184(2)°. The space group was assigned as P‐1. The structure was solved by direct methods using the SHELXTL suite v6.10. All nonhydrogen atoms were refined with anisotropic thermal parameters. Hydrogen atoms located on heteroatoms were found from the Fourier difference map. All remaining hydrogen atoms were fixed in idealized positions. The final model refined to a goodness fit of 1.033 with R ₁=0.0590 (I>2σ) and wR ₂=0.1438.