Coumarin is a constituent of many plants. It has found use in industry mainly due to its strong fragrant odour. Coumarin has been used in the treatment of a range of ailments such as cancer, burns, brucellosis and rheumatic disease [l]. The most commonly used quantitative method for coumarin analysis in biological samples is high per formance liquid chromatography (HPLC). However, this method r...

The solvation and rotational relaxation dynamics of coumarin 153 have been investigated in a dicationic ionic liquid (IL), 1,6-bis-(3-methylimidazolium-1-yl)hexane bis-(trifluoromethylsulfonyl)amide ([C6(MIm)2][NTf2]2), for the first time to provide a comprehensive and a quantitative understanding of the nature of the ionic fluid and its influence on the average solvation and rotational relaxat...

In the fresh tissues of Prunus mahaleb L., three classes of phenolics were characterised: phenolic acid derivatives (main compound being o-coumaric acid glucoside), quercetin glycosides, and anthocyanins (cyanidin 3,5-diglucoside, cyanidin 3-sambubioside, cyanidin 3-xylosyl-rutinoside and cyanidin 3-rutinoside). Coumarin was also identified. The kernels showed a high content of coumarin (0.87 m...

The formation of soluble 1:2 complexes within hydrophilic γ-cyclodextrin (γ-CD) thioethers allows to perform photodimerizations of aromatic guests under controlled, homogenous reaction conditions. The quantum yields for unsubstituted anthracene, acenaphthylene, and coumarin complexed in these γ-CD thioethers were found to be up to 10 times higher than in the non-complexed state. The configurati...

The mechanism of formation of coumarin (1) by Perkin reaction from salicylaldehyde was shown to involve exclusively a basecatalyzed intramolecular aldol-type condensation of O-acetyl salicylaldehyde (2) as an obligatory intermediate followed by dehydration. Direct evidence in support of this contention was provided by the formation of coumarin and 3-phenyl coumarin(5) as the sole products in th...

In the title compound, C15H8O2S, the coumarin moiety is approximately planar (r.m.s. deviation of the 11 non-H atoms = 0.025 Å) and is slightly inclined with respect to the plane of the thio-phen-3-yl ring, forming a dihedral angle of 11.75 (8)°. In the crystal, the three-dimensional architecture features a combination of coumarin-thio-phene C-H⋯π and π-π [inter-centroid distance = 3.6612 (12) ...

2-Dimethyl-2H-Chromenes, Coumarin Derivatives, Phase-Transfer Catalysis 2,2-Dimethyl-5H-pyrano(3,2-c)-l-benzopyrano-5-one(2) and 4H-2,3-dihydro-3-methyl-2methylene-furan-l-benzopyran-4-one (3), two new coumarin derivatives were synthesised from 4-hydroxycoumarin by treating with 3-chloro-3-methylbut-l-yne and 3-chlorobut-l-yne respectively, both reactions progressing via the phase-transfer cata...

In the title compound, C20H14O4, the dihedral angle between the two coumarin ring systems is 52.37 (19)°, showing a gauche arrangement across the C-C bond which links the two units. The carbonyl groups of the two coumarin units adopt an s-trans arrangement. In the crystal, pairs of C-H⋯O hydrogen bonds and π-π inter-actions [centroid-centroid distance = 3.631 (2) Å] connect the mol-ecules into ...

In the title compound, C17H12O5, the dihedral angle between the planes of the coumarin ring system (r.m.s. deviation = 0.015 Å) and the benzene ring is 48.04 (10)°. The central CO2 group subtends a dihedral angle of 27.15 (11)° with the coumarin ring system and 74.86 (13)° with the benzene ring. In the crystal, mol-ecules are linked by C-H⋯O inter-actions, which generate a three-dimensional net...

7-hydroxy coumarin undergoes neutral conditions with alkyl propiolates in the presence of triphenylphosphine, and bysubstituation the corresponding aryl vinyl ethers was obtained in good yields