Potassium 8-hydroxyquinolinate

Use. Potassium hydroxyquinoline sulphate is used topically in concentrations of 0.05 to 0.5%. 

It was shown by Hartley and LinnelF that potassium hydroxyquinoline sulphate is almost certainly a simple mixture of potassium sulphate and 8-hydroxyquinoline sulphate. This is substantiated by extraction of the compound with ethanol, when complete separation of the two components results. 

The 4-aminophenazone method (see under Phenol, p. 514) has been applied by Savidge to a cream containing 7-5 per cent of zinc oxide and 0 1 per cent of potassium hydroxyquinoline sulphate. 

Traces of copper and lead are separated [301] from macro amounts of calcium, magnesium, sodium, and potassium by adsorption from the sample onto active carbon modified with hydroxyquinoline dithizone or diethyldithiocarbamate. 

Potassium salt of ethyl 7-chloro-6-fluoro-4-hydroxyquinoline-3-carbox-ylate (759, R = Cl, R1 = F) was isolated in pure form from a mixture of isomeric ethyl 5-chloro-6-fluoro- and 7-chloro-6-fluoro-4-hydroxyquino-line-3-carboxylates (758 and 759, R = Cl, R1 = F) by heating in DMF in the presence of an excess of potassium carbonate (89USP4868305). 

Iodoquinol Iodoquinol, 5,7-diiodo-8-quinolinol (37.2.2), is made by iodination of 8-oxyquinoline (37.2.1) using a mixture of potassium iodide/potassium iodate. The initial 8-hydroxyquinolin (37.2.1) is made from 2-aminophenol and glycerol in the presence of sulfuric acid and nitrobenzene (Skraup synthesis) [39,40]. 

Hydroxyquinoline (113) with diazomethane gives the betaine AT-methyl-8-quinolinate (114) which also results from treatment of 8-hydroxyquinoline methiodide with potassium carbonate (Scheme 95) (59JCS1579). 

The hydroxyquinoline (39-2) provides the starting material for a quinolone that incorporates a hydrazine function. Reaction of (39-2) with 2,4-dintrophenyl O-hydroxylamine ether (41-1) in the presence of potassium carbonate leads to a scission of the weak N-O hydroxylamine bond by the transient anion from the quinolone the excellent leaving character of 2,4-dinitrophenoxide adds the driving force for the overall reaction, resulting in alkylation on nitrogen to form the hydrazine (41-2). The primary amine is then converted to the formamide (41-3) by reaction with the mixed acetic-formic anhydride. Alkylation of that intermediate with methyl iodide followed by removal of the formamide affords the monomethylated derivative (41-4). Chlorine at the 7 position is then displaced by A-methylpiperazine and the product saponified. There is thus obtained amifloxacin (41-6) [48]. 

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... 

Hydroxyquinoline (5%) and potassium iodide (6m) in acidic medium red precipitate of 8-hydroxyquinoline-tetraiodobismuthate... 

ANTIMONYL-7-FORMYL-8-HYDROXYQUINOLINE-5-SULPHONATE see AQE320 ANTIMON YL POTASSIUM TARTRATE see AQG250 ANTIMONY, compounded with NICKEL (1 1) see NCYIOO... 

Casnati and co-workers have devised a calixarene crown ether (7.17) that shows a preference for potassium over sodium of 22,000.85 A macrocyclic polyether with attached 8-hydroxyquinoline groups (7.18) favors barium over other alkaline earth cations by a factor of more than 10 million.86 Compound (7.19) shows a preference of magnesium over calcium of 590.87 Compound (7.20) has the highest known binding constant for Ag(I), log K 19.6.88... 

In Inorganic Chemistry, typical spray reagents for cations include potassium iodine (0.2%, aqueous), hydrogen sulphide (saturated aqueous solution), ammonium sulphide (0.2 N, aqueous), quercetin (0.1%, alcoholic), l-(2-pyridylazo)-2-naphthol (PAN) (0.2%, methanolic), oxine (8-hydroxyquinoline) (1% methanolic, view under visible and UV light), and sodium rhodizonate (0.5%, aqueous). Reaction with dithizone to produce coloured dithizonate chelates of many metals is particularly suitable if quantitative spectrometric analysis (in situ or after elution) is to be carried out. Anions are detected with bromocresol purple (0.1%, alcoholic), 1% ammoniacal silver nitrate + 0.1% alcoholic fluorescein/UV light, zirconium alizarin lake (0.1% in HC1 solution), and ammonium molybdate (1%, aqueous) followed by SnCl2 (1%) and HC1 (10%). Typical detection limits range from 10 ng (10 9g) to several pg (10 6g). 

---