Chemical Properties
Yellow powder or chunks or Slightly yellow needle-like crystals. freely soluble in ethanol, ether and hot water. brown in color with ferric chloride.
Uses
4-Hydroxycoumarin may be regarded as a phenylenetetronic acid , and like tetronic acid forms condensation products with aldehydes.
Synthesis of biscoumarin derivatives by the reaction of aldehydes and 4-hydroxycoumarin using ruthenium(III) chloride hydrate as a versatile homogeneous catalyst.
Uses
4-Hydroxycoumarin is involved in annulation reactions, due to the relatively high acidity of the C-H bond at the 3-position: a three-component reaction with isocyanides and dialkyl acetylene dicarboxylates affords annulated 4H-pyrans.
Uses
4-Hydroxycoumarin is a plant derived antioxidant, protecting against lipid peroxidation, as well as a potential inhibitor of HIV-1 Integrase. 4-Hydroxycoumarins are a very important class of biologically active drugs which are widely used as anticoagulants-Warfarin and Acenocoumarol.
Definition
ChEBI: 4-hydroxycoumarin is a hydroxycoumarin that is coumarin in which the hydrogen at position 4 is replaced by a hydroxy group. It is a conjugate acid of a 4-hydroxycoumarin(1-).
Synthesis Reference(s)
The Journal of Organic Chemistry, 25, p. 677, 1960
DOI: 10.1021/jo01074a630
Flammability and Explosibility
Not classified
Synthesis
4-Hydroxycoumarin is prepared by the reaction of o-hydroxyacetophenone and Diethyl carbonate. The steps are as follows:
General procedure: To a stirred mixture (1.15 mmol) and sodium hydride (138 mg, 5.75 mmol) in 5 ml dry toluene, a solution of the diethyl carbonate (1.15 mmol) in dry toluene was dropped. The mixture was reacted at 0°C for 30 min, then heated to reflux and reacted for another 4 h. The reaction mixture was quenched with water (20 mL) at ice bath and neutralized to pH 7 with 2 N HCl. The precipitate was filtered, washed with cold water and dried to get 6a-f. 1.2.1.1. 4-Hydroxy-2H-chromen-2-one (6a) White solidyield: 95; 1H NMR (600 MHz, DMSO-d6) δ 12.53 (s, 1H), 7.83 (d, J = 7.2 Hz, 1H), 7.65 (d, J = 7.8 Hz, 1H), 7.38-7.34 (m, 2H), 5.60 (s, 1H).
Purification Methods
Crystallise 4-hydroxycoumarin from water and dry it in a vacuum desiccator over pKEst Sicapent. [Beilstein 18/1 V 378.]
References
[1] Synthetic Communications, 2001, vol. 31, # 8, p. 1195 - 1200
[2] Journal of the American Chemical Society, 2010, vol. 132, # 1, p. 185 - 194
[3] New Journal of Chemistry, 2018, vol. 42, # 16, p. 13985 - 13997
[4] Organic Letters, 2017, vol. 19, # 4, p. 934 - 937
[5] Patent: US5959109, 1999, A
