- ANODIC OXIDATION OF PYRONES AND RELATED COMPOUNDS
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Triacetic lactone, 4-hydroxycoumarins, and kojic acid derivative were subjected to anodic oxidation in MeOH containing LiClO4 or NaCN to afford the corresponding methoxy or cyano compounds.In a basic media, however, dipyrone and dicoumarol were produced from triacetic lactone and 4-hydroxycoumarin, respectively.The formation process of 3-methoxytriacetic lactone as well as of 3-cyanotriacetic lactone is also presented.
- Iguchi, Masanobu,Nishiyama, Atsuko,Eto, Hideo,Yamamura, Shosuke
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Read Online
- Functionalized 4-hydroxy coumarins: Novel synthesis, crystal structure and DFT calculations
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A novel short-step methodology for the synthesis in good yields of functionalized coumarins has been developed starting from an activated precursor, the N-hydroxysuccinimide ester of O-acetylsalicylic acid. The procedure is based on a tandem C-acylation-c
- Stefanou, Valentina,Matiadis, Dimitris,Melagraki, Georgia,Afantitis, Antreas,Athanasellis, Giorgos,Igglessi-Markopoulou, Olga,McKee, Vickie,Markopoulos, John
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experimental part
p. 384 - 402
(2011/03/22)
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- Synthesis and antimicrobial screening of 4H-2-acetyl-3-acetyamido furo[3,2-c] benzopyran 4-one, 11H-2,4-dimethyl-3,4-dihydro-3-amino-4-hydroxy- pyrimido [3,2-d]furo [3,2-c] benzopyran-11-one and 4H-2-acetyl-3-(3′- methyl-1′,2′,4′-triazol-4′-yl) furo[3,2-c] benzopyran 4-one
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A suspension of 4H-2-acctyl-3-amino furo [3,2-c] benzopyran 4-onc 5a-d in aqueous sodium hydroxide is treated with acetyl chloride to give 4H-2-acelyl-3-acclylamido furo[3,2-c] benzopyran 4-onc 6a-d. The compounds 6a-d and hydrazine hydrate in absolute alcohol is relluxed to give 11H-2,4-dimethyl-3,4-dihydro-3-amino-4-hydroxy-pyrimido[3,2-d] furo [3,2c]benzopyran-11-one 7a-d which in formic acid is relluxed for 5 hr to give 4H-2-acetyl-3-(3′-methyl-1′,2′,4′-triazol-4′-yl) furo[3.2-c]benzopyran 4-one 8a-d. The structures of all these compounds have been established on the basis of the spectral and analytical data. All compounds have showed good antimicrobial activity.
- Mulwad,Hegde
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scheme or table
p. 1558 - 1564
(2010/03/24)
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- Novel short-step synthesis of functionalized γ-phenyl-β- hydroxybutenoates and their cyclization to 4-hydroxycoumarins via the N-hydroxybenzotriazole methodology
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A novel method for the synthesis of functionalized 3-substituted 4-hydroxycoumarins is reported. C-Acylation compounds were derived from the reaction of the N-hydroxybenzotriazole ester of the functionalized acetyl salicylic acids and a variety of active methylene compounds and cyclized to the title compounds. The synthesis is simple and the compounds are produced in yields varying from 39 to 80%. The structure of the newly prepared C-acylation compounds was thoroughly studied through NMR spectroscopy for the first time in the literature.
- Athanasellis, Giorgos,Melagraki, Georgia,Chatzidakis, Haralambos,Afantitis, Antreas,Detsi, Anastasia,Igglessi-Markopoulou, Olga,Markopoulos, John
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p. 1775 - 1782
(2007/10/03)
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- 2-Cyano indan-1,3-diones
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Pharmaceutical compositions are produced comprising as the active ingredient a compound of the formula STR1 or a pharmaceutically acceptable, nontoxic salt thereof or hydrate thereof, wherein R1, R2, R3 and R4 are each hydrogen, halogen, lower alkyl or lower alkoxy, or any two of the groups R1, R2, R3 and R4, taken together with the carbon atoms to which they are joined complete a substituted or unsubstituted carbocyclic ring, and X is a bond or an oxygen atom, is combined with a pharmaceutically acceptable, nontoxic inert diluent or carrier. Those compounds wherein R1, R2, R3 and R4 are not all simultaneously hydrogen are novel. When X is a bond, the compounds may be prepared by reacting an appropriately substituted 3-dyanomethylene phthalide with a base and, thereafter, if desired, converting the compound to a salt. When X is an oxygen atom, the compounds may be prepared by reacting a suitably substituted benzene derivative with an activated carbonyl group having a carbanion of the formula NC--CH--R, wherein R is a carboxylic acid ester group, and thereafter, if desired, converting the compound into a salt.
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