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Quinoline compounds

Polycychc aromatic hydrocarbons (PAHs) are carcinogens produced by the thermal breakdown of organic materials. These are widely distributed in both food and the environment, and are some of the principal carcinogens in cigarette tar and air pollution. Of over 20 PAHs isolated, benzopyrene and quinoline compounds are the most commonly encountered in foods, particularly those which are broiled or fried (111). Shellfish living in petroleum contaminated waters may also contain PAHs (112). [Pg.481]

Although only ppm levels of nitrogen are found in the mid-distillates, both neutral and basic nitrogen compounds have been isolated and identified in fractions boiling below 345°C (12). Pyrroles and indoles account for about two-thirds of the nitrogen. The remaining nitrogen is found in the basic pyridine and quinoline compounds. Most of these compounds are alkylated. [Pg.170]

Work also prepared a series of carbinolamines and polyamines without a quinoline nucleus but, in other respects, conforming in type and range of molecular weight, with quinoline compounds known to possess plasmocidal activity. As none of these were active, it seems clear that the quinoline nucleus in the cinchona alkaloids and in certain synthetic anti-malarials is a potent factor in the production of plasmocidal action. Later the same author made (1942) a series of lepidylamine derivatives of the form R. Q. CHj. NH[CH2] . NEtj, which were found to be inactive, in spite of their similarity to the active examples of the type R. Q. NH[CH2] . NEt2 prepared by Magidson and Rubtzow. Rubtzow (1939) has also shown that an isomeride of dihydroquinine (II) with the quinuclidine nucleus attached via the carbinol group at C in the quinoline nucleus was inactive in an infection of Plasmodium prcecox in finches. [Pg.475]

In summary, we may add that bacterial utilization of quinoline and its derivatives as a rule depends on the availability of traces of molybdate in the culture medium [363], In contrast, growth of the bacterial strains on the first intermediate of each catabolic pathway, namely, the lH-2-oxo or 1 II-4-oxo derivatives of the quinoline compound was not affected by the availability of molybdate. This observation indicated a possible role of the trace element molybdenum in the initial hydroxylation at C2. In enzymes, Mo occurs as part of the redox-active co-factor, and all the Mo-enzymes involved in N-heteroatomic compound metabolism, contain a pterin Mo co-factor. The catalyzed reaction involves the transfer of an oxygen atom to or from a substrate molecule in a two-electron redox reaction. The oxygen is supplied by the aqueous solvent. Certainly, the Mo-enzymes play an important role in the initial steps of N-containing heterocycles degradation. [Pg.170]

The use of amprolium (58) at 125 p.p.m. in feed soon failed to give complete control of some Eimeria species. The closely related quinoline compounds, buquinolate (60) and decoquinolate (61), and the pyridine, clopidol (62), were introduced as replacement for amprolium (58). However, all the compounds have been beset by resistance problems and today the prophylactic treatment of coccidiosis is heavily dependent upon the sodium ionophore monensin (63). [Pg.213]

Figure 1. Suggested route for the formation of the imidazo-quinoline compounds. Figure 1. Suggested route for the formation of the imidazo-quinoline compounds.
A similar electrophile, iodosyl triflate, CF3S020I0, was employed with arylsi-lanes [98]. The same reagent upon reaction with Me3SiCN formed (CN)2I+ TfO" which was coupled with tributyltin substituted arenes or heterocycles to afford bis(heteroaryl)iodonium triflates, e.g. dithienyl and difuryl derivatives [99]. However, this method gave poor results with nitrogen heterocycles. For them another approach was developed based on the reaction of the appropriate lithium compound with / -(dichloroiodo)chloroethylene (Scheme 33). Pyridine and quinoline compounds were formed in this way in moderate yield (23-71 %) [100]. [Pg.85]

In the reduction of pyridine and quinoline compounds, hydrogenation generally occurs.2... [Pg.64]

Oxime derivative (32) can be cyclized to quinoline compound (33) under Lewis-acid catalysis (Scheme22) <95CL5>. [Pg.215]

Various quinoline compounds can be prepared by a series of Skraup syntheses utilizing different oxidizing agents. Isoquinoline differs from quinoline at the N position (at 2) [ 1]. [Pg.214]

In the search for quinoline compounds that evade the resistance problem, bisquinolines were found very promising being active against CQ-resistant strains [123]. The ferrocenyl bisquinoline (Fig. 19) remained more efficient on the Dd2 CQ-... [Pg.173]

The intramolecular cyclization of substituted 2-alkenylanilines (57) catalyzed by PdCl2 affords a novel route directly to 1,2,3-trialklylindoles (58), which can be further methylated to Fischer s base salts. The cyclization reaction is complex, and the reaction mixture contains much of the corresponding quinoline compound (59). The composition of the crude product and its yield depend strongly upon the nature of the substituents. The yields of pure indoles are moderate.63... [Pg.30]

A genetic relationship between an indole derivative and a quinoline compound was therefore established in animals, analogous to that in the vegetable kingdom in which certain quinoline alkaloids are known to be formed from tryptophan. [Pg.64]

Another program to obtain a reversible proton-pump inhibitor came from workers at SmithKline French, who selected the substituted quinoline compound SK F 96067 as an early clinical candidate (164). SKF 96067 is a reversible inhibitor of the H /K -ATPase protein of the parietal cell (164). In clinical trials SKF 96067 was found to be a more potent inhibitor of gastric acid secretion than the Hz-receptor antagonist ranitidine. This compound reached Phase III clinical trials but has now been discontinued (165). The compound was followed by SKF 97574 (159) that, although of similar potency to that of SKF 96067, displayed a significantly longer duration of action in vivo. [Pg.117]

A number of other miscellaneous systems that bear some relationship to Reissert compounds have also been reported but will not be covered in depth here. Thus, for example, the reaction of isoquinoline, potassium cyanide, and alkyl chloromethyl ethers give 116. A similar compound was also prepared from quinoline. Compounds of type 117 have been reported to undergo rearrangements similar to Reissert compounds. A... [Pg.213]

SAR studies were performed on compoimds containing the 9H-isothia-zolo[5,4-fc]quinoline-3,4-dione (ITQ) nucleus and it was found that some of them are potent antibacterial agents (see Scheme 101) [114,115]. They were prepared from compound 353, which was treated with cyclopropyl isothiocyanate in DMF and then with Mel. Compound 354 (94%) was obtained and treated with in NaH in DMF to give the isothiazolo[ 5,4-fo] quinoline compound 355 (93%). Its treatment with anhydrous NaSH gave the corresponding mercaptan (84%), which was directly cychsed without purification to 356 (85%) in the presence of hydroxylamine-O-sulfonic acid. Microwave-assisted Suzuki-Miyaura cross-coupling of the ITQ nucleus 356 with the desired aryl-boronic esters or acids afforded derivatives 357, typically, in 30-50% yield after HPLC purification (Scheme 87). [Pg.236]

Pyrimethamine is a folic-acid antagonist its therapeutic action is based on differential requirements between host and parasite for nucleic acid precursors involved in growth as it selectively inhibits plasmodial dihydrofolate reductase. Pyrimethamine inhibits the enzyme dihydrofolate reductase that catalyzes the reduction of dihydrofolate to tetrahydro-folate. This activity is highly selective against plasmodia and Toxoplasma gondii. It does not destroy gametocytes but arrests sporogony in the mosquito. Pyrimethamine possesses a blood schizonticidal, and some tissue schizonticidal activity may be slower than that of 4-amino-quinoline compounds. [Pg.606]

Quinoline compounds and the plants that contain them have historically anchored the antimalarial arsenal, and they remain principal drugs today. Quinine and its diastereomer, quinidine, are quinoline alkaloids which were isolated in 1820 from the bark of the Cinchona tree, by virtue of the traditional South American use of this bark to treat intermittent fevers. Quinine is an effective schizonticide (i.e., it kills the form of the parasite in peripheral blood), but because it also affects mammalian lysosomes, the drug has been associated with significant adverse toxicity (48,50). The development of synthetic derivatives of quinine has resulted in improvement in potency and selectivity over the parent compound. Chloroquine and mefloquine are more potent and less toxic than quinine (49,51), thus, chloroquine had largely replaced quinine in clinical use however, resistance of P. falciparum to chloroquine has been reported... [Pg.517]

Quinoline compounds provided the first photographic film sensitizers the cyanine dye ethyl red extended photography from the blue into the green and then in 1904,... [Pg.121]

A quinoline compound called montelukast sodium is the active ingredient in SINGULAIR, which is the Merck dmg for asthma. [Pg.209]

An interesting modification of Camps reaction was presented recently. It was based on the use of isatoic anhydride or benzoxazinones as active components for the in situ formation of intermediate amides, which were readily cyclized to the desired products. Thus, reaction of isatoic anhydride or benzoxazinones with malonates and/or ketoesters afforded libraries of quinoline compounds in high yields even at multikilogram scale. ... [Pg.494]

Hydroxy-quinoline carboxylates, prepared using the Could-Jacobs reaction, have also been frequently used as precursors for the synthesis of biologically interesting quinoline compounds. For example, the syndiesis of... [Pg.505]

The Doebner-von Miller reaction was used as a method of choice for the synthesis of several biological active quinoline compounds. The anti-malarial drug primaquine, which acts against the hepatic stage of plasmodia infection, was synthesized by a Skraup reaction fi om 4-methoxy-2-nitroaniline and glyceron in the presence of sulfiiric acid. The nitro group was then reduced and alkylated with 4-bromo-l-phthalimidopentane to provide the protected primaquine, which was deprotected by using hydrazine. ... [Pg.509]

Internal ynones and alkynes have been frequently used as starting materials for the synthesis of quinoline compounds. Ynones can act as Michael acceptors with various nucleophiles, affording intermediate enones, which are readily cyclized to quinolines. ... [Pg.510]

Intramolecular or intermolecular Heck-type reactions were also used in the synthesis of poly-substituted quinoline compounds. Palladium-catalyzed reaction between vinyl or aryl halides and ortAo-allyl-substituted-A -tosyl-anilides produces dihydroquinolines in an intermolecular fashion, where reaction of acrylates intramolecularly affords 4-quinolones. ° ° ... [Pg.511]


See other pages where Quinoline compounds is mentioned: [Pg.230]    [Pg.205]    [Pg.357]    [Pg.400]    [Pg.221]    [Pg.317]    [Pg.216]    [Pg.421]    [Pg.875]    [Pg.101]    [Pg.372]    [Pg.693]    [Pg.186]    [Pg.518]    [Pg.95]    [Pg.148]    [Pg.639]    [Pg.506]   


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