Regioselective substitution of 6,7-dichloroquinoline-5,8-dione: synthesis and X-ray crystal structure of 4a,10,11-triazabenzo[3,2-a]fluorene-5,6-diones

Bioorg Med Chem. 2003 Apr 17;11(8):1829-33. doi: 10.1016/s0968-0896(02)00667-3.

Abstract

6,7-Dichloroquinoline-5,8-dione (1) was reacted with a number of 2-aminopyridine derivatives. Of the several possible products of this reaction, 4a,10,11-triazabenzo[3,2-a]fluorene-5,6-dione (6), produced by condensation and rearrangement, was obtained as the major product, and its structure was subsequently unambigously determined by X-ray crystallographic study. Ortho-quinones were produced via nucleophilic substitution at position C7, which was unexpected, considering that para-quinones were produced via C6 substitution in the reaction between compound 1 and ethyl acetoacetate in our previous work. Such unexpected nucleophilic substitution at C7 provides an effective, yet simple route, to the preparation of biologically active ortho-quinone derivatives.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology
  • Crystallography, X-Ray
  • Doxorubicin / pharmacology
  • Drug Screening Assays, Antitumor
  • Fluorenes / chemical synthesis
  • Fluorenes / chemistry
  • Fluorenes / pharmacology
  • Humans
  • Inhibitory Concentration 50
  • Molecular Structure
  • Quinolines / chemistry*
  • Quinones / chemical synthesis
  • Quinones / chemistry*
  • Quinones / pharmacology
  • Stereoisomerism
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents
  • Fluorenes
  • Quinolines
  • Quinones
  • 6,7-dichloroquinoline-5,8-dione
  • Doxorubicin