- A mild and efficient method for the deformylation of 5-formyl uracils and synthesis of 4,4¢-methylidenebis(1-phenyl-3-methyl-5-pyrazolone)
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6-Substituted 5-formyl uracils undergo an interesting reaction with 1-phenyl-3-methyl-5-pyrazolone in the presence of base catalyst to afford deformylated uracils and 4,4¢-methylidenebis(1-phenyl-3-methyl-5- pyrazolone) in excellent yields. Georg Thieme V
- Deb, Mohit L.,Majumder, Swarup,Bhuyan, Pulak J.
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scheme or table
p. 1982 - 1984
(2010/03/26)
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- New heterocyclic derivatives of 3-formyl-4-hydroxycoumarin
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Condensation of 4-hydroxy-2-oxo-2H-[1]benzopyran-3-carboxaldehyde 1 with triacetic acid lactone 2, 5, 5-dimethylcyclohexan-1,3-dione 5 and 3-methyl-1-phenyl-5-pyrazolone 7 in refluxing ethanol affords 3-acetoacetylpyrano[3,2-c][1]benzopyran-2,5-dione 3, 7-(4-hydroxycoumarin-3-yl)- 10,10-dimethyl-8-oxo-8,9, 10,11-tetrahydropyrano [3,2-c] coumarin 6 and methylidine-bis-4,4′-[3-methyl-5-oxo-1-phenylpyrazole] 9. Pyrazoles 4a,b and isoxazole 4c are obtained by treatment of 3 in acetic acid with hydrazine, phenylhydrazine and hydroxylamine. Structures of all these compounds have been established by IR, 1H NMR and mass spectral data.
- Siddiqui, Zeba N.,Asad, Mohammad
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p. 2704 - 2709
(2007/10/03)
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- Novel reactions of 5-chloro-4-formyl-3-methyl-1-phenylpyrazole with active methylene compounds
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Condensation of 5-chloro-4-formyl-3-methyl-1-phenylpyrazole (1) with malononitrile in the presence of piperidine or ammonium acetate affords the corresponding pyrazole derivatives (2-4). Base-catalyzed cyclocondensation of 1 with hippuric acid or ethyl glycinate hydrochloride gives the oxazolone 6 and 5-amino-3-methyl-6-oxo-1-phenyl-1,6-dihydropyrano[2,3-c]pyrazole (7) respectively. Treatment of 1 with ethyl cyanoacetate in basic medium produce ethyl α-cyano-β-(5-chloro-3-methyl-1-phenylpyrazol-4-yl)acrylate (8) which reacts with nitrogen nucleophiles to give compounds 9-12. Transesterification and/or hydrolysis of ester group has been observed on treatment of 8 with methyl alcohol in basic medium leading to the formation of acrylate derivatives (13-15). Compound 8 on treatment with ethyl acetoacetate or cyclohexanone undergoes condensation with subsequent cyclization and/or dearylation to give the adducts 16 and 17 respectively. Structures of all the products have been established by elemental analysis, IR, PMR and mass spectral data.
- Shiba,Harb,Hassan,El-Kassaby,Abou-El-Regal
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p. 426 - 430
(2007/10/03)
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- SYNTHESIS AND REACTIVITY OF CYANOVINYL AND DIMETHYLAMINOVINYL CARBANIONS BASED ON THE AMINOMETHYLENE DERIVATIVES OF 5-PYRAZOLONE
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The reaction of 4-methylene-substituted 1-phenyl-3-methyl-5-pyrazolones with potassium cyanide and sodium dimethylamide leads to the formation of the cyanovinyl and dimethylaminovinyl carbanions respectively.The potassium salt of the cyanovinyl carbanion enters readily into carboxylation, cyanoethylation, alkylation and acylation.
- Smirnova, N. P.,Kvitko, I. Ya.,El'tsov, A. V.
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p. 582 - 590
(2007/10/02)
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