4,8-dihydroxy quinoline

The above-mentioned Pigment Green 10 is the 1 2 nickel complex of the azo pigment obtained from p-chloroaniline and 2,4-dihydroxy-quinoline (33) ... 

Its synthesis follows the usual pathway of coupling diazotized 4-chloroaniline onto 2,4-dihydroxy-quinoline and subsequently treating the product with a nickel (II) salt. 

However, dyes have also been generated from l-phenyl-3-methyl-5-aminopyr-azole [101], 2,4-dihydroxy quinoline [102], 2,6-dihydroxypyridine [103], 2,6-diami-nopyridine [104], 2,4,6-triaminopyridine [105], and 3-phenyl-5-hydroxyisoxazole [106]. The solubility of such dyes may be enhanced by introduction of polyether moieties [107],... 

C]Tryptophan gave inactive alkaloids but tritiated 2,4-dihydroxy-quinoline (34) and its N-methyl derivative were incorporated into (47) (0.009 % and 0.020% respectively) an early route had suggested the derivation of what was essentially (34) from tryptophan. Radioisotope dilution showed the presence of both these quinoline precursors together with iV-acetyl- and N-methyl-anthranilic acid in A. baueri. A satisfactory incorporation of N-methylanthranilic acid into (47) was found in Evodia xanthoxyloides, and this, together with its natural occurrence, indicates that early methylation may be important in the biosynthesis of acridone alkaloids. 

Quinoline and Furoquinoline Alkaloids (Fig. 151). (Activated ) anthranilic acid reacts with (activated ) acetic acid to 2,4-dihydroxyquinoline. Probably 2-aminobenzoyl acetic acid, which is in a pH-dependent equilibrium with 2,4-dihydroxy quinoline, or an activated derivative of this compound is an intermediate. On the one hand 2,4-dihydroxy quinoline is transformed to echinorine. On the other hand it is a precursor of 3-prenylated chinoline alkaloids, isopropyl-dihydrofuroquinolines and furoquinolines. 

Fattorusso, E., S. Forenza, L. Minale, and G. Sodano Isolation of 3,4-dihydroxy-quinoline-2-carboxylic acid from the sponge Aplysina aerophoba. Gazz. Chim. it. 101, 104(1971). 

On the basis of its reaction with diazomethane, 2,4-dihydroxyquino-line was reported to exist as 4-hydroxyquinol-2-one in the solid state and as an equilibrium mixture of this form with 2-hydroxyquinol-4-one in solution. Using the infrared criteria for o- and p-quinonoid forms (see Section II,L), the spectra of 2,4-dihydroxy-pyridine and -quinoline indicated that both quinonoid forms, e.g., 12 (Z = NH) and 13 (Z — NH), were present and that the nonaroraatic form (43) was absent. ... 

ZN(C)153, 00ZN(C)323, 00ZN(C)857, 01MI2, 01MIP4, 01TL5849). 5-Amino-8,9-dihydroxy-2,3-dihydro-l//-pyrimido[l,2-u]quinoline-3-carboxylic acid moiety 4 was also identified as a chromophoric moiety of certain... 

Ar-quinolin-2-yl)imino]propionates by injection or sublimation at 530°C yielded a mixture of 3-amino- and 3-ethoxy-l//-pyrimido[l,2-rz]quinolin-l-ones <2004AJC577>. An oxidative cascade for the biomimetic formation of the pyoverdine chromophore was supported by incubation of 2-[(4-hydroxyphenyl)- and 2-[(2-(3,4-dihydroxipheny-l)ethyl]-l,4,5,6-tetrahydropyrimidines with polyphenol oxidase or Pseudomonas extract to afford a mixture of 8,9-dihydroxy-2,3-dihydro- and -2,3,5,6-tctrahydro-l //-pyrimido[ 1,2- ]quinolines <20030L2215>. Oxidation of 2-[(2-(3,4-dihydroxiphenyl)ethyl]-l,4,5,6-tetrahydropyrimidine with MnOz gave a similar result. 

Schwarz et al. in agreement with Shukla observed the formation of 2-Oxo-l, 2-dihydroquinoline, 8-hydroxy-2-oxo-l, 2-dihydroquinoline, 8-hydroxycoumarin, and 2,3-dihydroxy-phenylpropionic acid were found as intermediates of quinoline transformation by P. fluorescens 3 and P. putida 86 [325], They compared that metabolic pathway with the one obtained for Rhodococcus strain B1 (Fig. 22). This bacterium was unable to yield denitrogenated metabolites (i.e., 2-oxo-l, 2-dihydroquinoline, 6-hydroxy-2-oxo-l, 2-dihydroquinoline, and 5-hydroxy-6-(3-carboxy-3-oxopropenyl)-lH-2-pyridone). 

As can be seen, in both the 5,6- and the 7,8-dihydroxy-2(lH)quinolinone pathways, after initial hydroxylation adjacent to the N-heteroatom, the benzene moiety of the quinoline ring is transformed to a dihydroxy derivative 5,6- or 7,8-, respectively, which subsequently undergoes ring cleavage. However, neither of them involves C—N bond cleavage and consequently do not lead to denitrogenated products. 

US patent 6,734,308, Crystal forms of 6-[(4-chloro-phenyl)-hydroxy-(3-methyl-3H-imidazol-4-yl)-methyl]-4-(3-ethynyl-phenyl)-l-methyl-lH-quinolin-2-one, 2,3,-dihydroxy-butanedioate salts and method of production [108]. The invention relates to crystal forms of 6-[(4-chloro-phenyl)-hydroxy-(3-methyl-3H-imidazol-4-yl)-meth-yl]-4-(3-ethynyl-phenyl)-1 -methyl-lH-quinolin-2-one, 2,3-dihydroxy butanedioate salts, and to pharmaceutical compositions containing the above compound, methods of treating hyperproliferative diseases, such as cancers, in mammals, especially humans by administering the above compound, and to methods of preparing the crystal forms of the above compound and related compounds. 

The reactions of anilines (R =4-MeO and 3-C1) and diethyl acetylmalonate in nitrobenzene at 230-235°C for 1-2 hr gave 2,4-dihydroxy-3-acetyl-quinolines (667, R = 6-MeO and 7-C1). In the case of 3-chloroaniline, a mixture of the isomeric 5- and 7-chloroquinolines was obtained (46JA324). The 7-chloroquinoline was the major isomer. 

First generation COMT inhibitors such as pyrogallol, U-0521 (3, 4-dihydroxy-2-methylpropiophenone), tropolone, and 8-hydroxy quinoline (Figure 10) were... 

A few extensions of the Conrad-Limpach synthesis have been applied to the synthesis of 4,7-phenanthrolines. Unlike o-phenylenediamine, which gives a quinoxaline derivative, p-phenylenediamine reacts with excess of ethyl ethoxalylpropionate to give an intermediate bisanil, which cyclizes in hot diphenyl ether to afford 3,8-dicarboethoxy-l,10-dihydroxy-2,9-dimethyl-4,7-phenanthroline in high yield.237 With diethyl ethoxymethylenemalonate as condensing agent, 6-amino-8-methoxy-quinoline has been converted into 2-carboethoxy-l-hydroxy-6-methoxy-4,7-phenanthroline.238 A related condensation affording 1-... 

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