Hydroxy-2-pyridone

The most convenient synthesis of 6-hydroxy-2-pyridones is by the condensation of a P-ketoester, eg, ethyl acetoacetate, with an active methylene compound, eg, malonic ester, cyanoacetic ester, and an amine. The amine can be omitted if an acetamide is used and in some cases this modification results in a higher yield. [Pg.297]

Heterocyclic coupling components that have been coupled with diazotized ami-nophenyltrimethylammonium chloride are l-alkyl-6-hydroxy-2-pyridone [93], 1-amino-3-hydroxy-isoquinoline [94], and 2,4-diamino-6-hydroxypyrimidine [95], The trialkylammoniumaryl residue may also be connected to the aromatic diazo component via a sulfone or a sulfonamido function [96], Disazo dyes in this series (e.g., 34) [77901-21-4] may also be generated from monoazo dyes that still contain a primary amino group by dimerization using phosgene [97] or cyanuric chloride [98],... [Pg.239]

Furo-2-pyridones. 1,4-Dimethyl -3- cyano -5-propargyl -6- hydroxy -2-pyridone dissolved in coned. H2SO4, and poured on ice after a few min. 5,6- (2-methyl-furano)-l,4-dimethyl-3-cyano-2-pyridone. Y 70%. F. e. s. J. Reisch, Arch. Pharm. 297, 754 (1964) furo[3,2-c]coumarins s. Arch. Pharm. 299, 457 (1966). [Pg.342]

Cyclizations of /3-ketoesters with cyanoacetantide with ethyl cyanoacetate and ammonia give 5-cyano-6-hydroxy-2-pyridones. Ethyl 4,4,4-trifluoroaceto-acetate and cyanoacetamidein the presence of sodium methoxide form 3-cyano 6-hydroxy-4 trifluoromethyl-2-pyridone (XII-127) after crystallization from 15% hydrochloric acid. This pyridone appears to tautomerize in the solid state to 5-cyano-6-hydroxy-4-trifluoromethyl-2-pyridone. ... [Pg.625]

The condensation of an aldehyde with ethyl cyanoacetate and ammonia to give 4-alkyl-3,5-dicyano-6-hydroxy-2-pyridone (XIl-198) probably proceeds through the oxidation of an intermediate glutaric acid imide -197). Only small amounts of the reduction products (XI-199)could be isolated. Additional pathways for the oxidation of W-197 to XII-198 were not excluded. ... [Pg.643]

The 4-hydroxy-6-methyl-2-pyridone structure (XII-483) is consistent with its NMR, ir, and uv spectra and is similar to that of 4-hydroxy-2-pyridone. Ultraviolet spectra in water and ethanol and infrared spectra (KBr) show that glutazine and several of its derivatives (XII484 R = H,CN, CONH, C02Et) exist as an equilibrium mixture of the 4-amino-6-hydroxy-2-pyridone (XII-484a) and the 4-aniino-2,6-pyridinedione (XII-484b). ... [Pg.737]

Glutaconimide, which exists predominately in lactam fcrms, is mainly 6-hydroxy-2-pyridone (XII-485a b c = 25 60 15) in water, as shown by a comparison of its ultraviolet spectra with those of model compounds. The... [Pg.737]

Hydroxy-2-pyridone (XU-516) and a large excess of diazomethane give 6-methoxy-2-pyridone (2%), 6-methoxy-lmethyl-2-pyridone (4%), 2,6-dimeth-oxypyridine (8%), and the 3-( methylhydrazonc) of l-methyl-2,3,6-pyridine-trione (XD-517) (14%). ° 6-Methoxy-2-pyridone and diazomethane give a mixture of O- and yV-methylation products. 6-Hydroxy- l-methyl-2-pyridone gives 6-methoxy-lmethyl-2-pyridone and XD-517. ° ... [Pg.753]

Heating ammonium salts of 4-alkyl-3,5-dicyano-6-hydroxy-2-pyridone and... [Pg.785]

Pyridinols and pyridones and phosphorus pentasulfide give predictable products. 4-Pyridinol and phosphorus pentasulfide in pyridine give 4-pyridine-thione, while 2,6-di-f-butyl-4-pyridone gives bis(4-(2,6-di-r-butylpyridinyl)] sulfide. . /V-Alkyl-3,5-dibromo-2,6-dimethyl- and iV-alkyl-3 -dibromo-2,6-di-phenyl-4-pyridone are converted to the corresponding 4-pyridinethiones. Ammonium salts of 4-alkyI-3,5-dicyano-6-hydroxy-2-pyridones and phosphorus pentasulfide in xylene and pyridine form pyridinium salts of the corresponding 6-mercapto-2-pyridinethiones(XII-630). ... [Pg.793]

The preparative nitration of pyridones has been reviewed recently.The nitrations of several 2- and 4-pyridones have been studied kinetically. Pyridones with p < 1.5 are nitrated as their free bases under all conditions. 4-Pyridone (p g 3.27) is nitrated as the free base in 65 to 85% sulfuric acid but as the conjugate acid in 85 to 98% H2S04." 6-Hydroxy-2-pyridone and its N- and 0-methyl derivatives are rapidly converted to the... [Pg.806]

Cyano-6-hydroxy-2-pyridones, by cyclization, 625 3-Cy suio-6-hydroxy-4-tri f luoro-methyl-2-pyridone, 624 3-Cyano-6-hydroxy-4-tri fluoro-methyl-2-pyridone, 625... [Pg.1205]

C19H2 2N4O2 r 1-Propyl-3,5-dicyano-4-phenyl-6-hydroxy-2-pyridone propylamine, 41B, 290 42B, 190... [Pg.126]

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