A chromeno[4,3-d]pyrazolo[3,4-b]pyridinone derivative 3 bearing thieno[2,3-d]pyrimidine moiety, 5-methyl-1-phenyl-3-(thieno[2,3-d]pyrimidin-4-yl)chromeno[4,3-d]pyrazolo[3,4-b]pyridin-6(3H)-one, was efficiently prepared in 75% yield by the reaction of 3-phenyl-1-(thieno[2,3-d]pyrimidin-4-yl)-1H-pyrazol-5-amine 1 with 3-acetyl-2H-chromen-2-one 2 presence FeCl3-SiO2 as a catalyst refluxing ethanol...

The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthes...

The reaction of dibenzoylacetylene with 4-alkylaminocoumarins in THF/H2O (50:50) lead to 4-(alkylamino)-3-(1,4-dioxo-1,4-diphenylbut-2-en-2-yl)-2H-chromen-2-one derivatives in good yields. When the reaction carried-out in DMSO the cyclized products 2-hydroxy-1-alkyl-3-(2-oxo-2-phenylethylidene)-2-phenyl-2,3-dihydrochromeno [4,3-b] pyrrol-4(1H)-ones were formed in good yields.

(7-Hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid methyl ester(1) upon reaction with ethyl bromoacetate furnishes (7-ethoxycarbonylmethoxy-2-oxo-2H-chromen-4-yl)-acetic acid methylester (2), which on treatment with 100% hydrazine hydrate yields (7-hydrazinocarbonylmethoxy-2-oxo-2H-chromen-4-yl)-acetic acid hydrazide (3). The condensation of compound 3 with different aromatic aldehydes afforded a se...

We have developed a new technology called multi-catalysis for the sequential one-pot synthesis of highly functionalized heterocycles. A practical and novel multi-component aniline-, self- and Brønsted acid-catalyzed selective process for the sequential one-pot synthesis of highly substituted 2-(2-hydroxy-aryl)-cyclopentane-1,3-diones, 3,9-dihydro-2H-cyclopenta[b]chromen-1-ones and 3,3-dimethyl-...

Coumarin and their derivatives have drawn much attention in the pharmacological and pharmaceutical fields due to their broad range and diverse biological activities. In the present work, starting from the 6-amino-7-hydroxy-4-methyl-2H-chromen-2-one, a series of 6-(substituted benzylamino)-7-hydroxy-4-methyl-2H-chromen-2-ones 1-11 was synthesized and assessed for their anti-inflammatory activity...