Research Showcase Gallery (Poster 2125)

Aligning 4-Hydroxycoumarins into β-chains, 3-Substituted 7- dimetylamino -4-hydroxycoumarins

Abstract

Many 3-Substituted 4-hydroxycoumarins often form translational β-chains through hydrogen-bonding along a crystallographic axis in their solid states. So dominant is this interaction that both racemic and enantiomeric phases of phenprocoumon (3-1-phenylethyl-4-hydroxycoumarin) form similar translational chains in their crystalline structures, which are essentially pseudoisomorphous. The translational repeat distance si 717 pm, and occurs along a crystallographic axis. Enhancing the hydrogen-bonding interaction is hypothesized for judicious substitution on the coumarin core. In this work, 7-dimethylamino-4-hydroxycoumarin was prepared with a plan to form 3-substituted derivatives to test this hypothesis. 7-Dimethylamino-4-hydroxycoumarin was formed by addition of 3-dimethylaminophenol and malonic acid in the presence of phosphoryl chloride. The brown solid was characterized by spectroscopy and the crystal structure of its hydrate was determined. Several attempts to carry out additions of this compound to form 3-substituted derivatives failed. However, reaction of 7-dimethylamino-4-hydroxycoumarin with benzaldehyde lead to a substituted dicoumarol, which could be reduced to 3-benzyl-7-dimethylamino-4-hydroxycoumarin. This compound was characterized by spectroscopy, and was found in the solid state to form well aligned translational β-chains with a shorter and stronger repeating distance (702 pm) compared to the unsubstituted 4-hydroxycoumarins. 3-Benzyl-4-hyroxycoumarin, in contrast, forms modestly dis-aligned β-chains. A model for these enhanced interactions is proposed.


About the Presenters

photo of Victor Cosovan

Victor Cosovan

Victor Cosovan, a 4th year Neuroscience student at Washington State University Vancouver who has completed courses in general chemistry, organic chemistry, and biochemistry. He is a pre-Med student preparing for medical school applications. His interests in derivative of 4-hydroxycoumarin come from his organic chemistry professor, Dr. Valente who guided him in the process of structural and chemical analysis of organic compounds.

photo of Elisei Cosovan

Elisei Cosovan

Elisei Cosovan, a 4th year neuroscience undergrad student at WSUV with completed courses in general-, organic-, and bio-chemistry. He is a pre-Dental student preparing for application process into dental school. His interests in derivative of 4-hydroxycoumarin come from his organic chemistry professor, Dr. Valente who guided him in the process of structural and chemical analysis of organic compounds.