- Improved syntheses of 5-hydroxy-2-pyridones (2,5-dihydroxypyridines)
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Improved syntheses of 5-hydroxy-2-pyridone, 6-chloro-5-hydroxy-2-pyridone, 2,4-dihydroxynicotinic acid, and three methyl-substituted 5-hydroxy-2-pyridones are reported. Copyright Taylor & Francis Group, LLC.
- Behrman
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p. 1168 - 1175
(2008/09/18)
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- SPIROCYCLIC MEISENHEIMER COMPLEXES. XXXVI. POSSIBILITY OF THE FORMATION OF ZWITTERIONIC SPIRO-? COMPLEXES FROM THE POLYNITRO AROMATIC DERIVATIVES OF 3-HYDROXY-2-PYRIDONE, 8-HYDROXYQUINOLINE N-OXIDE, HYDROXYNAPHTHOQUINONE, AND HYDROXYANTHRAQUINONE
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3-Picryloxy-2-(1H)-pyridone, its N-methyl derivative, 3-(5,7-dinitro-8-quinolyloxy)-2(1H)-pyridone, 1-hydroxy-5- and 1-hydroxy-8-picryloxy-9,10-anthraquinones, 1,8-dipicryloxy-9,10-anthraquinone, 5-picryloxy-1,4-naphthoquinone, and 8-picryloxyquinoline N-
- Knyazev, V. N.,Drozd, V. N.
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p. 101 - 108
(2007/10/02)
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- 1-hydroxy-2-pyridones, a process for their preparation, and medicaments which contain them, and intermediates formed in the preparation of the 1-hydroxy-2-pyridones
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New 1-hydroxy-2-pyridones of the general formula I STR1 in which R1, R2 and R3, which are identical or different, denote hydrogen or lower alkyl having 1-4 carbon atoms, R1 and R3 preferably being hydrogen, and R2 preferably being methyl, X denotes S or, preferably, O, Y denotes hydrogen or up to 2 halogen atoms, namely chlorine and/or bromine, Z denotes a single bond or the bivalent radicals O, S, --CR2 -- (R=H or C1 -C4 -alkyl) or other 2-valent radicals with 2-10 carbon and, optionally, oxygen and/or sulfur atoms linked to form a chain, it being obligatory when the radicals contain 2 or more oxygen and/or sulfur atoms for the latter to be separated by at least 2 carbon atoms, and it being possible for 2 adjacent carbon atoms also to be linked together by a double bond, and the free valencies of the carbon atoms being saturated by H and/or C1 -C4 -alkyl groups, Ar denotes an aromatic ring system which has up to two rings and can be substituted by up to three radicals from the group comprising fluorine, chlorine, bromine, methoxy, C1 -C4 -alkyl, trifluoromethyl and trifluoromethoxy, are prepared by a variety of process variants. The compounds and their physiologically tolerated salts with inorganic or organic bases mainly have antimycotic, anti-bacterial and antiviral activity. The compounds of the formula V STR2 in which R1, R2, R3, X, Y, Z and Ar have the same meaning as in formula I, which occur in the preparation of the compounds of the formula I, are also new.
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- A Three-Step Synthesis of δ-Aminolaevulinic Acid
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Piperidine-2,5-dione (4) is prepared by catalytic hydrogenation of 5-hydroxy-2-pyridone (3).Ring opening of the lactam 4 with concentrated hydrochloric acid yields the hydrochloride of δ-aminolaevulinic acid (2).
- Herdeis, Claus,Dimmerling, Anna
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p. 304 - 306
(2007/10/02)
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- Process for the manufacture of 1-hydroxy-2-pyridones
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New 1-hydroxy-2-pyridones of the general formula SPC1 In which R1 is alkyl of 1 to 17 carbon atoms, cycloalkyl of 5 to 8 carbon atoms, cyclohexylalkyl or phenalkyl both having 1 to 3 carbon atoms in the alkylene chain or α-furyl, all of which may be substituted by halogen, and R2 to R4 are hydrogen or lower alkyl, or two adjacent substituents together form a trimethylene or tetramethylene chain, and in which R1 to R4 together contain at least 2 carbon atoms, are prepared by contacting unsaturated δ-keto esters or mixtures thereof with hydroxylamine and subjecting the products to cyclization.
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