- Synthesis of functionalized pyrano[3,2-c]pyridines and their transformations to 4-hydroxy-3[(1E)-N-hydroxyalkanimidoyl]pyridones
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Reaction of 4-hydroxy-6-methyl-2(1H)-pyridones 1a and 4-hydroxy-1,6- dimethyl-2(1H)-pyridones 1b with diethyl malonates 2a-e leads to the formation of pyrano[3,2-c]pyridines 4a-j. Degradation of 4a-i affords the corresponding ketones 6a-i. Condensation of ketones 6a-i with hydroxyl amine or phenyl hydrazine hydrochloride is described. Copyright Taylor & Francis Group, LLC.
- El-Essawy, Farag A.,Khattab, Ahmed F.,Zahran, Magdy A.,Gomaa, Sherif H.
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p. 3225 - 3237
(2008/02/12)
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- Synthesis of N-Acylacetoacetamide using 2,2,6-Trimethyl-1,3-dioxin-4-one
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Diketene-acetone adduct (2,2,6-trimethyl-1,3-dioxin-4-one) 1 reacts with amide NH to give the corresponding N-acetoacetates 2.Formamide and basic amides such as picolinamide, on treatment with the adduct, are transformed to the N-acyl-2,6-dimethyl-4-oxo-4H-pyran-3-carboxamide (4a and 4p) together with the corresponding N-acetoacetates.Keywords--diketene-acetone adduct; 1,3-dioxin-4-one; acetylketene; diketene; acetoacetylation; 4-pyrone derivatives; N-acylacetoacetamide
- Sato, Masayuki,Kanuma, Norio,Kato, Tetsuzo
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p. 1315 - 1321
(2007/10/02)
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- Synthesis of Methylpyridine Derivatives. XXXIV. Condensation of Acetoacetamide with Ketones to form Pyridone Derivatives
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Condensation of acetoacetamide (1) with acetone in polyphosphoric acid (PPA) gave 4,6-dimethyl-2(1H)-pyridone (2a) in 32percent yield.Similarly, the amide 1 was condensed with 2-butanone, 2-pentanone, 3-pentanone, cyclopentanone, cyclohexanone, cycloheptanone, acetophenone, and propiophenone to give the corresponding pyridone derivatives (2b-i) in 13-76percent yields.Condensation of the amide 1 with acetylacetone and ethyl acetoacetate gave 3-acetyl-4,6-dimethyl-2(1H)-pyridone (5) and ethyl 4,6-dimethyl-2(1H)-pyridone-5-carboxylate (6), respectively.Self-condensation of the amide 1 in PPA gave 3-acetyl-4-hydroxy-6-methyl-2(1H)-pyridone (7).
- Kato, Tetsuzo,Sato, Masayuki,Noda, Masaki,Itoh, Tetsuo
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p. 2244 - 2247
(2007/10/02)
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