- Ca(II)-catalyzed, one-pot four component synthesis of functionally embellished benzylpyrazolyl coumarins in water
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A facile one-pot, four-component synthesis of biologically important benzylpyrazolyl coumarins in water has been demonstrated using environmentally benign Ca(II) as the catalyst. Participation of aliphatic aldehydes has been described for the first time. Short reaction times, high yields and chromatography free isolation of the products, usage of eco-friendly catalyst and solvent are the key features of this method.
- Yaragorla, Srinivasarao,Pareek, Abhishek,Dada, Ravikrishna
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supporting information
p. 4770 - 4774
(2015/07/20)
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- Biscoumarin: New class of urease inhibitors; Economical synthesis and activity
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A variety of biscoumarins (1-21) with variable substituents at C-11 were synthesized with an improved method and evaluated as urease inhibitors. The synthesized compounds showed varying degree of urease inhibitory activity ranging from 15.06-91.35 μM. The size and electron donating or withdrawing effects of substituents influenced the activity, which lead to the urease inhibitors.
- Khan, Khalid Mohammed,Iqbal, Sajid,Lodhi, Muhammad Arif,Maharvi, Ghulam Murtaza,Zia-Ullah,Choudhary, Muhammad Iqbal,Atta-ur-Rahman,Perveen, Shahnaz
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p. 1963 - 1968
(2007/10/03)
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- The Chemistry of Coumarin Derivatives Synthesis of 3-Alkyl-4-hydroxycoumarins by Reductive Fragmentation of 3,3'-Alkylidene-4,4'-dihydroxybis
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Treatment of 3,3'-alkylidene-4,4'-dihydroxybis 1 with NaBH3CN in refluxing MeOH affords 3-alkyl-4-hydroxycoumarins 2 and 4-hydroxycoumarin (3; Scheme 1).The reaction may take place via hydride trapping of alkylidenechromandiones C formed from 1 in a retro-Michael reaction.Such a retro-Michael reaction of 1 might be biologically relevant.The presence of C during the reductive fragmentation 1 --> 2 is suggested by Diels-Alder and nucleophilic trapping of the alkylidenechromandiones C as well as from cross-over experiments with coumarins other than 3 (see Scheme 2).The reductive fragmentation of 1 allows the chemo- and regioselective synthesis of a variety of 3-alkyl-4-hydroxycoumarins 2 (see Table).
- Appendino, Giovanni,Cravotto, Giancarlo,Tagliapietra, Silvia,Ferraro, Stefano,Nano, Gian Mario,Palmisano, Giovanni
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p. 1451 - 1458
(2007/10/02)
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- Quantitative structure activity relationships for dicoumarol antivitamins K in the uncoupling of mitochondrial oxidative phosphorylation
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The dynamic structure of dicoumarol derivatives substituted on the methylene bridge was studied by nuclear magnetic resonance (nmr) spectroscopy. These molecules may be considered as dimers with restricted rotation around the methylene bridge, held by intramolecular hydrogen bonds; the presence of the substituent R modifies this dynamic process, mainly the facility of exchange of the 2 hydroxyl protons. These compounds were compared in respect of their potency in uncoupling oxidative phosphorylation in pig heart mitochondria; the data were correlated with constants used to characterize the substituent R; to make a potent uncoupler, R should be as small and as hydrophilic as possible. The results are discussed in consonance with the postulated mechanisms of action of the uncouplers, but no simple conclusion could be drawn, especially concerning the role of the dissociable protons.
- Labbe Bois,Laruelle,Godfroid
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