Crystal structure and identification of resonance forms of diethyl 2-(3-oxoiso-1,3-dihydrobenzofuran-1-ylidene)malonate

Mikhail S. Tyumentsev, Mark R. St J. Foreman, Britt-Marie Steenari, Alexandra M. Z. Slawin

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


The reaction of diethyl malonate with phthaloyl chloride in acetonitrile in the presence of triethylamine and magnesium chloride results in the formation of the title compound, diethyl 2-(3-oxo-1,3-dihydro-2-benzofuran-1-ylidene)propanedioate, C15H14O6. One of the ester groups of the diethyl malonate fragment is almost coplanar with the isobenzofuran unit, while the plane of the other group is perpendicular to it [dihedral angles = 5.45(3) and 83.30(3)°, respectively]. The C—C and C—O distances both in the heterocyclic furan ring and the diethyl malonate fragment are indicative of the dipolar delocalization occurring within the isobenzofuran unit. This delocalization is likely to be responsible for the unusual intermolecular O···O contact [2.756(2)Å], established between the O atom of the furan ring and the carbonyl O atom of the diethyl malonate fragment. In the crystal, weak C—H···O interactions are observed, which link the molecules into [100] chains.
Original languageEnglish
Pages (from-to)1576-1579
Number of pages4
JournalActa Crystallographica Section E
Issue number10
Early online date29 Sept 2017
Publication statusPublished - Oct 2017


  • Crystal structure
  • 3-alkylidene-3H-isobenzofuran-1-ones
  • Delocalization
  • Enolate


Dive into the research topics of 'Crystal structure and identification of resonance forms of diethyl 2-(3-oxoiso-1,3-dihydrobenzofuran-1-ylidene)malonate'. Together they form a unique fingerprint.

Cite this