Sodium xanthate

The reaction of chloroformates with sodium xanthates results in the formation of alkyl xanthogen formates that are useful as flotation agents in extraction of metals from their ores (48). 

The required xanthates 1 can be prepared from alcohols 5 by reaction with carbon disulfide in the presence of sodium hydroxide and subsequent alkylation of the intermediate sodium xanthate 6. Often methyl iodide is used as the alkylating agent ... 

The collector emulsion was more stable when using potassium xanthate instead of sodium xanthate. 

Fluoroethyl xanthate, FCH2CH2S-CS-OEt, was a yellow oil formed by the action of sodium xanthate on bromo-fluoroethane. The compound has a l.d. 50 of 50 mg./kg. for subcutaneous injection into mice, thus showing it to be considerably less toxic than M.F.A. 

The transfer of a trifluoromethyl group of xanthate R—O—(C=S)—S—CF3 is a recent and powerful method for the trifluoromethylation of olefin.An important and interesting point of this method is that the reaction product is a xanthate itself, able to undergo further radical reactions and permitting cascade reactions, as exemplified in Figure 2.40. The starting xanthates R—O—(C=S)—S—CF3 are easily prepared from trifluoroacetic anhydride and sodium xanthate. 

Carbon disulfide combines readily with a sodium rdkoxide to yield the corresponding sodium xanthate. Tlie procedure for the prepi ration is... 

Sodium wolframate. See Sodium tungstate Sodium xanthate. See Sodium xanthogenate Sodium xanthogenate CAS 140-90-9 4741-30-4 Synonyms Ethyixanthic acid sodium salt Sodium ethyixanthate Sodium xanthate Empirical C3H5NaOS2 Formula C2H50C(S)SNa Properties YIsh. powd. sol. in water and alcohol m.w. 144.19... 

Xanthate formation (barattering, sulfitation) is used to produce a water-soluble cellulose derivative. At X = 300, the product is soluble, with 0.4 xanthate group per glucose unit. Commercial xanthates (or viscoses) contain 27% cellulose, 14% NaOH, 8% CS2, and 51% water. Pure sodium xanthates are colorless. The orange-red color of the commercial product is due to sodium trithiocarbonate, which results from the reaction of CS2 with free caustic soda ... 

These properties impair the use of native cellulose in the manufacture of useful products, except those made of threads. Modifications of cellulose usually require the cellulose to be solubilised. In the viscose process, cellulose is treated with 18-20% aqueous sodium hydroxide. The mass is aged to allow oxidative degradation of the chains in order to reduce molecular weight. Then the alkali cellulose is treated with carbon disulfide, leading to the soluble sodium xanthate derivative of cellulose, as shown in Equation 3.23. 

The content of the active ingredient of xanthate is usually about 79-82 % in China. The quality guarantee period of xanthate is generally half-year. The technological parameter for the preparation of xanthates varies with experiment condition. Based on reports, the main technological parameters for various sodium xanthates can be given as follows ... 

V-Ethylpyridinium chloride/DMF (1 /I), A-ethylpyridinium chloride/pyridine (1 /I), trifluoroacetic acid, aqu. solutions of alkalies (ice-cold), beryllium perchlorate, cdcium thiocyanate, cupriammonium hydroxide, cupriethylenediamine, sodium xanthate, tetramethylammonium hydroxide, zinc chloride/hydrochloric acid (cold), zinc chloride (hot), cone, phosphoric acid, cone, sulfuric acid. See also table on cellulose in this Handbook... 

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