Ethyl 3-(9-chloro-10-oxo-9,10-dihydroanthracen-9-yl)-5-methylisoxazole-4- carboxylate

Nathan S. Duncan, Howard D. Beall, Alison K. Kearns, Chun Li, Nicholas R. Natale

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


The asymmetric unit of the title compound, C21H 16ClNO4, contains two independent molecules (A and B), each adopting a conformation wherein the isoxazole ring is roughly orthogonal to the anthrone ring. The dihedral angle between the mean plane of the isoxazole (all atoms) and the mean plane of the anthrone (all atoms) is 88.48 (3)° in one molecule and 89.92 (4)° in the other. The ester is almost coplanar with the isoxazole ring, with mean-plane dihedral angles of 2.48 (15) and 8.62 (5)°. In both molecules, the distance between the ester carbonyl O atom and the anthrone ketone C atom is about 3.3 Å. The anthrone ring is virtually planar (r.m.s. deviations of 0.070 and 0.065 Å) and adopts a shallow boat conformation in each molecule, as evidenced by the sum of the six intra-B-ring torsion angles [41.43 (15) and 34.38 (15)° for molecules A and B, respectively]. The closest separation between the benzene moieties of anthrones A and B is 5.1162 (7) Å, with an angle of 57.98 (5)°, consistent with an edge-to-face π-stacking interaction. In the crystal, weak C - H⋯O and C - H⋯N interactions link the molecules, forming a three-dimensional network.

Original languageEnglish
Pages (from-to)o315-o316
JournalActa Crystallographica Section E: Structure Reports Online
Issue number3
StatePublished - Mar 2014


  • Data-to-parameter ratio = 17.8
  • Mean σ(C-C) = 0.002 A°
  • R factor = 0.033
  • Single-crystal X-ray study; T = 100 K
  • wR factor = 0.089


Dive into the research topics of 'Ethyl 3-(9-chloro-10-oxo-9,10-dihydroanthracen-9-yl)-5-methylisoxazole-4- carboxylate'. Together they form a unique fingerprint.

Cite this