Potassium ethyl xanthate

Into a 500 ml. round-bottomed flask, fitted with a reflux condenser, place 42 g. of potassium hydroxide pellets and 120 g. (152 ml.) of absolute ethyl alcohol. Heat under reflux for 1 hour. Allow to cool and decant the liquid from the residual solid into another dry 500 ml. flask add 57 g. (45 ml.) of A.R. carbon disulphide slowly and with constant shaking. Filter the resulting almost solid mass, after cooling in ice, on a sintered glass funnel at the pump, and wash it with two 25 ml. portions of ether (sp. gr. 0-720), followed by 25 ml. of anhydrous ether. Dry the potassium ethyl xanthate in a vacuum desiccator over silica gel. The yield is 74 g. If desired, it may be recrystallised from absolute ethyl alcohol, but this is usually unneceasary. 

Potassium n-butyl xanthate. Use 100 g. (123-5 ml.) of dry n-butyl alcohol, 18 g. of potassium hydroxide pellets, and 36 g. (28-5 ml.) of A.R. carbon disulphide. The yield of pure, dry potassium n-butyl xanthate CS(OC4H )SK, is 42 g. 

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Potassium ethyl xanthate Ethyl S-ethyl xanthate... 

Place 32 g. of potassium ethyl xanthate (Section 111,166) and 50 ml. of absolute ethyl alcohol in a 500 ml. round-bottomed flask provided with a double surface condenser. Add 32 g. (16-5 ml.) of ethyl iodide. No reaction appears to take place in the cold. Heat on a water bath for 3 hours a reaction sets in within 15 minutes and the yellow reaction mixture becomes white owing to the separation of potassium iodide. Add about 150 ml. of water, separate the lower layer, and wash it with water. Dry it with anhydrous calcium chloride or anhydrous calcium sulphate and distil from a 50 ml. Claisen flask. Collect the ethyl S-ethyl xanthate at 196-198°. The yield is 23 g. 

Fig. 1. Effect of particle size on the flotation recovery of a sulfide mineral. Mineral chalcocite [2112-20-9J, CU2S reagent potassium ethyl xanthate,...

X 10 M sodium oleate 1.5 X 10 M sodium oleate 10 M sodium oleate, pH = 8.1 10 Af potassium ethyl xanthate water... 

The initial hydrolysis of the xanthate in aqueous solutions at room temperature is characterized by the following reaction involving potassium ethyl xanthate ... 

For the manufacturiag of potassium ethyl xanthate, 400% excess of alcohol and equimolar quantities of 50 wt % aqueous potassium hydroxide and carbon disulfide were used (77). After 30 min at 40°C, the mixture was vacuum dmm dried. The product was obtained ia near quantitative yield and assayed at 95%. It is claimed that potassium amyl xanthate can be made with almost the same ratio of reactants and 80 wt % caustic potash (78). 

The described method of preparation of w-nitrophenyl disulfide is essentially that of Foss and co-workers and is a modification of that reported by Ekbom. The disulfide has been prepared by reaction of potassium ethyl xanthate with w-nitrobenzenedi-azonium chloride solution, followed by hydrolysis to yield the mercaptan, which is subsequently oxidized with potassium ferro-cyanide or dilute nitric acid to the disulfide. ... 

To a solution of 2a-bromo-5a-cholestan-3-one (7.1 g, 15.2 mmol) in 175 ml dry acetone is added dropwise a solution of potassium ethyl xanthate (2.6 g, 16.2 mmol) in 90 ml acetone. The reaction mixture is stirred at 20° for 12 hr and then evaporated to dryness under vacuum. The resulting solid is treated with 100 ml hexane to dissolve the organic material and the inorganic salts are removed by filtration. The hexane filtrate is concentrated under vacuum and the resulting yellow solid ca. 7.5 g) is crystallized from chloroform-ethanol to give the xanthate (137) as white needles, ca. 5 g mp 114-115°. 

Diazonium xanthates (ArN—NSCSOC2H5) can detonate, and this procedure should be followed carefully to ensure decomposition of the xanthate as it is formed. Under no circumstances should the diazonium solution and the potassium ethyl xanthate be mixed cold and the mixture subsequently heated. A severe detonation has been reported when such a procedure was employed during the preparation of thiocresol. 

It has been observed2 that the dropwise addition of an aqueous solution of potassium ethyl xanthate to a cold (0°) aqueous solution of diazotized orthanilic acid results in the immediate loss of nitrogen when a trace of nickel ion is present in the stirred diazonium solution.3 The catalyst can be added as nickelous chloride or simply by using a nichrome wire stirrer. When no nickel ion is added and a glass stirrer is employed, the diazonium xanthate precipitates and requires heat (32°) to effect decomposition. 

Figure 2.30 Critical pH for flotation with potassium ethyl xanthate in presence of sodium cyanide.

It is synthesized by reaction of the diazonium salt from amine 1 with potassium ethyl xanthate, followed by alkaline hydrolysis to afford thiophenol 2. 

Potassium 4-chloro-3,5-dinitrobenzene-sulfonate, 31, 46 Potassium cyanate, 31, 9 Potassium cyanide, 30, 84 32, 31, 63 Potassium ethyl xanthate, 30, 56 Potassium hydroxide, 30, 103 Potassium iodide, 30, 34 31, 31, 66 Potassium methyl sulfate, 31, 73... 

Aryl halodiazarines 119 when reduced with potassium ethyl xanthate are reported to give 3-aryl-5-ethoxy-1,2,4-thiadiazoles 120 (13%) along with the expected product benzonitrile (87%) (Equation 31). A mechanism involving fragmentation of the diazirine 119 is proposed <1999TL29>. 

Potassium 4-chloro-3,5-dinitrobenzene-sulfonate, 31, 46 Potassium cyanate, 31, 9 Potassium cyanide, 30,84 32,31,63 37,47 Potassium ethyl malonate, 37, 34 Potassium ethyl xanthate, 30, 56 Potassium fluoride, 36, 40 Potassium iodide, 30, 34 31, 31, 66 Potassium metal, 37, 29, 30 Potassium methyl sulfate, 31, 73 Potassium nitrate, 31, 46 Potassium 1-nitropropylnitronate, 37, 24 Potassium oxalate, 34, 83 Potassium permanganate, 30, 87 31, 59 Potassium sulfide, 32, 103 Potassium thiobenzoate, 32, 101 Potassium thiocyanate, 32, 39, 40 Prins reaction, 33, 72 Propane, 1, 3-dibromo-2, 2-Ws-(bromo-methyl)-, 31, 82... 

Potassium dodecylbenzenesulfonate, cosmetic surfactant, 7 834t Potassium ethyl xanthate, molecular formula, 5 713t... 

Table 1.2 Products of the interaction of sulphide minerals with potassium ethyl xanthate and the measured rest potential. Potassium ethyl xanthate (6.25 x 10 mol/L at pH = 7) reversible potential for oxidation to dixanthogen is 0.13 V (Allison et al., 1972)...

Persson et al. (1991) used diffuse reflection infrared Fourier transform (DRIFT) spectroscopy to study the interactions between galena, pyrite sphalerite and ethyl xanthate. They provided the evidence that the DRIFT spectrum of oxidized galena treated with an aqueous solution of potassium ethyl xanthate is practically identical with that of solid lead (II) ethyl xanthate, which can be formed as the only detectable siuface species on oxidized galena. Dialkyl dixanthogen is formed as the only siuface species in the reaction between oxidized pyrite and aqueous solution of potassium alkyl xanthate. 

Figure 5.2 Relationship between concentration (mol/L) of potassium ethyl xanthate and critical pH dashed line is the calculated results and symbols are the results from Fuerstenau et al. (1968)...

Baldauf, H. and Schubert, H., 1980. Fine Particles Processing, 1(39) 767 - 786 Ball, B. and Richard, R. S., 1976. The chemistry of pyrite flotation and depression. In Flotation, A. M. Gaudin Memorial volume, M. C. Fuerstanau(eds.), AIME, Inc., 1 458 - 484 Basiollio, C., Pritzker, M. D., Yoon, R. H., 1985. Thermodynamics, electrochemistry and flotation of the chalcocite-potassium ethyl xanthate system. SME-AIME Annual Meeting, New York, Preprint No. 85 - 86... 

Miner. Process Extra. Metall. Rev., 2 203 - 234 Hayes, R. A. and Ralston, J., 1988. The collectorless flotation and separation of sulphide minerals by control. Inter. J. Miner. Process, 23 55 - 84 Hepel, T. and Pomianowski, A., 1977. Diagrams of electrochemical equilibria of the system copper-potassium ethyl xanthate-water at 25°C. Int. J. Miner. Process, 4 345 - 361 Heyes, G. W. and Trahar, W. J., 1977. The natural floatability of chalcopyrite. Int. J. Miner. Process, 4 317-344... 

Kiba et al. propose the separation of technetium from rheniiun by carbon tetrachloride extraction using potassium ethyl xanthate as reducing agent. 

Previous preparations of 2-naphthalenethiol have included reduction of 2-naphthylsulfonyl chloride with zinc and acid4,5 or phosphorus and iodine.6-7 Alternatively, 2-naphthyldia-zonium chloride has been converted to the thiol using potassium ethyl xanthate and sodium carbonate.8 1 2 3 4... 

The synthesis and some reactions of meso-ionic 1,2-dithioM-ones (388) have been recently reported. The brown compound 388, R = R = Ph, has been prepared by several methods (i) the reaction betw i l,l,3,3-tetrabromo-l,3-diphenylacetone (PhCBrjCOCBrjPh) and potassium ethyl xanthate, (ii) the reaction between 1,3-diphenyl-propanetrione hydrate and tetraphosphorus decasulfide, (iii) 1,3-diphenylpropanetrione with hydrogen sulfide-hydrogen chloride in ethanol-chloroform yields the salt 389, R = R = Ph, X = Cl, which gives the meso-ionic I,2-dithiol-4-one with triethylamine, pyridine, or aqueous sodium bicarbonate. ... 

Phenyl-5-ethoxy-l,2,4-thiadiazole 74 has been synthesised as a by-product (13%) in the reaction of phenylbromodiazirine 73 with potassium ethyl xanthate and was suggested to have arisen by a radical mechanism. As expected, the major product formed in the reaction (87%) was benzonitrile, arising by reduction of the bromodiazirine <99TL29>. 

Two compounds were formed upon treatment of 174 with potassium ethyl xanthate (Equation 70) <1997CHE1306, 1998GHE297>. 

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