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Crystal Structure and Identification of Resonance Forms of Diethyl 2-(3-oxoiso-1,3-di-hydro-benzo-furan-1-yl-idene)malonate

Mikhail S Tyumentsev, Mark R StJ Foreman, Britt-Marie Steenari, Alexandra M Z Slawin

Acta Crystallogr E Crystallogr Commun. 2017 Sep 29;73(Pt 10):1576-1579.

PMID: 29250385

Abstract:

The reaction of diethyl malonate with phthaloyl chloride in aceto-nitrile in the presence of tri-ethyl-amine and magnesium chloride results in the formation of the title compound, diethyl 2-(3-oxo-1,3-di-hydro-2-benzo-furan-1-yl-idene)propane-dioate, C15H14O6. One of the ester groups of the diethyl malonate fragment is almost coplanar with the isobenzo-furan 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 isobenzo-furan unit. This delocalization is likely to be responsible for the unusual inter-molecular 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 inter-actions are observed, which link the mol-ecules into [100] chains.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP105533 Diethyl malonate Diethyl malonate 105-53-3 Price
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