Methoxy quinoline

Recently kinetic data have become available for the nitration in sulphuric acid of some of these hydroxy compounds (table 10.3). For 4-hydroxyquinoline and 4-methoxyquinoline the results verify the early conclusions regarding the nature of the substrate being nitrated in sulphuric acid. Plots of log Q against — (Lf + logioflHao) fo " these compounds and for i-methyl-4-quinolone have slopes of i-o, i-o and 0-97 at 25 C respectively, in accord with nitration via the majority species ( 8.2) which is in each case the corresponding cation of the type (iv). At a given acidity the similarity of the observed second-order rate constants for the nitrations of the quinolones and 4-methoxy-quinoline at 25 °C supports the view that similarly constructed cations are involved. Application of the encounter criterion eliminates the possibilities of a... 

Ewins has synthesised both substances from m-methoxybenzoic acid, which on nitration gave 2-nitro-3-methoxybenzoic acid, and this, on reduction and treatment with methyl iodide, yielded damasceninic acid, which, by esterification with methyl alcohol, furnished damascenine. Kaufmann and Rothlen found that the additive product of 8-methoxy-quinoline and methyl sulphate, on oxidation with permanganate, yields formyldamasceninic acid, MeO. CgH3(NMe. CHO). COOH, which can be transformed into damasceninic acid by warming with dilute hydrochloric acid. ... 

Alteration of the relative reactivity of the ring-positions of quinoline is expected and observed when cyclic transition states can intervene. Quinoline plus phenylmagnesium bromide (Et20,150°, 3 hr) produces the 2-phenyl derivative (66% yield) phenyllithium gives predominantly the same product along with a little of the 4-phenylation product. Reaction of butyllithium (Et 0, —35°, 15 min) forms 2-butylquinoline directly in 94% yield. 2-Aryl- or 6-methoxy-quinolines give addition at the 2-position with aryllithium re-agents, and reaction there is so favored that appreciable substitution (35%) takes place at the 2-position even in the 4-chloroquinoline 414. Hydride reduction at the 2-position of quinoline predominates. Reaction of amide ion at the 2-position via a cyclic... 

Reaction of 2,3-dihydro-3-hydroxy-3-methyl- 240 (R = Me), or a mixture of 2,3-dihydro-3-hydroxy-3-aryl-57/-pyrido[l,2,3-dfe]-l,4-benzoxazin-5-ones 240 (R = Ar) and (8-aroylmethoxy)quinolin-2(l//)-ones 241 (R = Ar) with ethyl 2-(bromomethyl)acrylate in the presence of activated Zn and hydroquinone gave 8-[(2,3,4,5-tetrahydro-4-methylidene-5-oxo-2-furanyl)-methoxy]quinolin-2(l//)-ones (242) (97HCA1161). 6,7-Dihydro derivatives of 240 reacted similarly (00HCA349). 

N4-(6-methoxy-8-quinolinyl)-1,4-pentanediamine diphosphate. N4-(6-methoxy-8-quinolinyl)-1,4-diaminopentane diphosphate. (RS)-8-(4-amino-l-methylbutylamino)-6-methoxy quinoline diphosphate. 

Clark et al. [81] determined the time course of A-acetylation of primaquine by Streptomyces roseochromogenous and Streptomyces rimosus by quantitative high performance liquid chromatographic analyses of the culture broths. The A-5-bistri-fluoroacetyl derivative of primaquine was used as an internal standard in the analysis for the quantitation of primaquine A-acetate in microbial culture broths. S. roseochromogenous forms the highest level of primaquine A-acetate at 24—36 h after substrate addition, while S. rimosus is slower in its acetylation, peaking at 3 days after substrate addition. The formation of a novel dimeric compound from the reaction of primaquine with 8-(4-phthalimido-l-methylbutylamino)-6-methoxy quinoline is also reported. 

Clark et al. [136] studied the excretion, distribution, and metabolism of primaquine in rats. The drug was administered intravenously, intraperitoneally, and orally and blood samples were collected at various time intervals. Primaquine was metabolized by oxidative deamination to give 8-(3-carboxy-l-methylpropylamino)-6-methoxy quinoline. The plasma levels of both primaquine and its metabolites were determined by high performance liquid chromatography. 

A number of heteroaromatic monothiocarboxylic acids are formed by Pseudomonas sp. From P. putida, there was isolated pyridine-2,6-di-(mon-othiocarboxylic acid) 46 (Scheme 16). Of interest is the fact that in P. stutzeri KC, a copper complex of 46 is the active agent for a one electron transfer in the bacterial biodegradation of CCI4. Methylation of P. putida extracts provides a number of related structures such as 47. In addition, a P. fluorescens sp. contains 8-hydroxy-4-methoxy-quinoline-2-monothiocarboxylic acid 48.98... 

Diazoxine, a red product which accompanies the formation of 8-methoxy-quinoline from 8-hydroxyquinoline and diazomethane, was first encountered by Caronna and Sansone in 1939. Later, it was suggested that the properties of this product were consistent with structure 189 (R = Me, R = R = H). ° Subsequently, this product has been prepared by treatment of the iodide 190 with potassium carbonate, and the betaine structure has been confirmed by spectroscopic and chemical studies. Compound 189 (R = Me, R = R = H) is isolated as hydrated violet-red needles. The UV and visible spectra are strongly dependent on the nature of the solvent the colors of solutions vary from yellow to blue. Bromination gives the 5,7-dibromo derivative (189 R = Me, R = R = Br), which is also obtained from... 

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-... 

Instead, evidence now favors the intermediacy of the highly organized mono-osmium complex 15. Various factors could contribute to its excellent enantioselectivity, the most important one being the formation of a binding site consisting of the two methoxy quinolines and the pyridazine linker. As confirmed by X-ray analysis and NMR studies [35,36], this pocket adopts a U-shaped conformation and is capable of perfectly binding aromatic substrates such as styrene through attractive interactions with the methoxyquinolines. In contrast, bulky... 

X Total yields were nearly quantitative for 4-hydroxy- and 4-methoxy-quinoline, About 5 % of an unidentified product was formed as well as the proportions ... 

Another chromophore, 8-alkoxy-5-chloroquinoline, was appended to the narrower rim of a calix[4]arene triamide, 44a and 44b (see fig. 38). If Nd111, Er111, and Ybm nitrates are added to acetonitrile solutions of these receptors, quenching of the methoxy quinoline luminescence oc-... 

FIGURE 7.4 Absolute configuration of R207910 [l-(6-bromo-2-methoxy-quinolin-3-yl)-4-dimethylamino-2-naphthalen-l-yl-l-phenyl-butan-2-ol]. (Source Andries, K. et al. 2005. Science, 307, 223. Reprinted with permission from AAAS.)... 

K17. Kotake, Y., and Kato, M., Xanthurenic acid, XVI. Action of 4-hydroxy-8-methoxy-quinoline-2-carboxylic acid as the inhibiting agent with regard to the diabetogenic property of xanthurenic acid. Proc. Japan Acad. 32, 210-213 (1956). 

The third synthesis reported was not complete as it did not produce the optically active base. Propyllithium is condensed with 8-methoxy-quinoline, and the product is hydrolyzed and oxidized with nitric acid to 2-propyl-5,6-pyridinedicarboxylic acid. This acid is converted via the ethyl ester, the hydrazide, the azide, and urethan to 2-propyl-... 

Two quinoline derivatives first synthesized though possessed significant antipyretic action, yet could not gain cognizance as a drug because of their high toxic effects on the red blood corpuscles and damaging after-effect on kidneys. These were, thalline and 6-methoxy quinoline. 

Craig (1944) first diseovered the presenee of an isomerie form of pamaquine known as isopamaquine, in the eommereial sample of pamaquine. The evolution of isopamaquine may be logically explained on the basis of the faet that the oximation of the amino alcohol obtained from the reduction of 1-acetyl-3-diethylamino propane aetually gives rise to 4-amino-1-diethylamino pentane as major product together with 3-amino-1-diethylamino pentane as minor product. The latter product then condenses with 8-amino-6-methoxy quinoline to yield isopamaquine as given below ... 

Amino-l-methylbutyl) amino]-6-methoxy quinoline phosphate (1 2) 1,4-Pentanediamine, N -(6-methoxy-8-quinolyl)-, phosphate (1 2) Primachin phosphate BP USP Int. P. Primaquine Phosphate (ICl Pharmaceuticals, U.K.)... 

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