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• 613-92-3 N-hydroxybenzenecarboximidamide 
• 20300-59-8 7-methoxycoumarin-3-carboxylic acid 

Relevant academic research and scientific papers

Isomeric 3-isoxadiazolylcoumarins and their derivatives

Here, we represent preparative methods of synthesis of isomeric 3-isoxadiazolylcoumarins and their derivatives. Two new synthetic methods have been developed for 3-[1,2,4-oxadiazol-5-yl]coumarins I. The first method is based on a three-component condensation of coumarin-;3-carboxylic acids, 1,1'-carbonyldiimidazole, and amidoximes. The second method essentially uses the interaction of 5-cyanomethyl-1,2,4-oxadiazoles with salicylic aldehydes. General approach for preparation of 3-[1,2,4-oxadiazol-3-yl]coumarins II has been worked out. Moreover, aforementioned synthetic ways open the way for the synthesis of 2-iminoderivatives III and IV not described before, those were diversified by reaction of nucleophilic substitution of 2-imino group with a numerous amino compounds.

3-Oxadiazolyl coumarins

Substituted coumarins are described having at the 7-position the group RO- where R is a substituted or unsubstituted alkyl, cycloalkyl or aralkyl group, and at the 3-position a 1,2,4- or 1,3,4-oxadiazolyl group which possesses a substituted or unsubstitut

Coumarin derivatives, their preparation and their use as optical brightening agents

Coumarin of the formula: SPC1 In which R1 represents an alkyl group having 1 to 5 carbon atoms, and either unsubstituted or substituted by a non-ionic and non-chromophoric group, R2 represents a benzene, styryl or heterocyclic residue such residue being unsubstituted or substituted by one or two non-ionic and non-chromophoric groups; process for the preparation of a coumarin of the above formula which comprises reacting an orthohydroxy-benzaldehyde of formula (II) upon an acid of formula (III) or one of its functional derivatives: SPC2 Wherein R1 and R2 have the same definitions as in claim 1; process for the fluorescent brightening of fibrous material of synthetic origin which comprises treating the material with a coumarin of the above formula; fluorescent brightening composition containing a coumarin of the above formula and a dispersing agent resulting from the condensation of naphthalene-sulphonic acids with formaldehyde in the presence of or absence of phenol compounds, said dispersing agent comprising 30% to 50% monosulphonated condensates, 30% to 50% disulphonated condensates and 10% to 40% trisulphonated or higher polysulphonated condensates; fibres of synthetic origin treated with a coumarin of the above formula or with a brightening composition as set out above.