Biomaterial Database

3-[1-(Ethylamino)ethylidene]-6-methyl-3H-pyran-2,4-dione. 1993

G Xiao, and D Van Der Helm, and R C Hider, and P S Dobbin

Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019.

The structural results clearly indicate that 3-[1-(ethylamino)ethylidene]-6-methyl-3H-pyran-2,4-dione exists as a keto-enamine tautomer in the solid state. The H atom bonded to N(9) refines with a normal temperature factor and the bond distance of the keto group [C(4)--O(13)] of 1.263 (1) A is elongated due to resonance. This resonance is also indicated by an averaging of the single bonds [C(2)--C(3), C(3)--C(4), C(4)--C(5) and C(8)--N(9)] and double bonds [C(3)--C(8) and C(4)--O(13)] in the crystal structure and by the fact that not only is the pyran ring planar [r.m.s. deviation 0.0212 (9) A] but also there is planarity for the whole molecule [r.m.s. deviation 0.074 (1) A]. A strong intramolecular hydrogen bond is found between the 4-oxo group and the amine H atom.

UI	MeSH Term	Description	Entries
D011753	Pyrones	Keto-pyrans.
D006860	Hydrogen Bonding	A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.	Hydrogen Bonds,Bond, Hydrogen,Hydrogen Bond
D014961	X-Ray Diffraction	The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Xray Diffraction,Diffraction, X-Ray,Diffraction, Xray,Diffractions, X-Ray,Diffractions, Xray,X Ray Diffraction,X-Ray Diffractions,Xray Diffractions
D015394	Molecular Structure	The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.	Structure, Molecular,Molecular Structures,Structures, Molecular