104990-27-4Relevant academic research and scientific papers
Investigation of the antioxidant properties of some new 4-hydroxycoumarin derivatives
Stanchev,Hadjimitova,Traykov,Boyanov,Manolov
experimental part, p. 3077 - 3082 (2009/09/27)
The aim of this investigation was to measure the activity of four 4-hydroxycoumarin derivatives - three of them were described before and one was newly synthesized. The substances were ethyl 2-[(4-hydroxy-2-oxo-2H-chromen-3-yl)(4-hydroxyphenyl)methyl]-3-oxobutanoate (SS-14), 4-[1-(4-hydroxy-2-oxo-2H-chromen-3-yl)-2-(ethoxycarbonyl)-3-oxobutyl]benzoic acid (SS-17), ethyl 2-[(4-hydroxy-2-oxo-2H-chromen-3-yl)(3-nitrophenyl)methyl]-3-oxobutanoate (SS-21) and ethyl 2-[(3,4,5-trimethoxyphenyl)(4-hydroxy-2-oxo-2H-chromen-3-yl)methyl]-3-oxobutanoate (T-2). The synthesis of T-2 consists of two steps. First step was Knoevenagel reaction between 3,4,5-trimethoxybenzaldehyde and ethylacetoacetate. Ethyl 2-(3,4,5-trimethoxy)-phenylmethyleneacetoacetate was the product. Second step was Michael addition reaction between the latter product and 4-hydroxycoumarin. All the compounds were tested in vitro for antioxidant activity in hypochlorous system. The assay was based on the luminol-dependent chemiluminescence of free radicals, which decreased in the presence of 4-hydroxycoumarin derivative. Compound SS-14 (ethyl 2-[(4-hydroxy-2-oxo-2H-chromen-3-yl)(4-hydroxyphenyl)methyl]-3-oxobutanoate) expresses the best scavenger activity at the highest concentration (10-4 mol/L).
ENANTIOSELECTIVE HANTZSCH DIHYDROPYRIDINE SYNTHESIS VIA METALATED CHIRAL ALKYL ACETOACETATE HYDRAZONES
Enders, Dieter,Mueller, Stephan,Demir, Ayhan S.
, p. 6437 - 6440 (2007/10/02)
An efficient, overall enantioselective variant of the Hantzsch synthesis of 4-aryl-1,4-dihydropyridines 5 (ee = 84 - 98percent), important biologically active compounds (e. g. as calcium channel blockers), is described.Key step of the new procedure is the
