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. 

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Potassium ethyl xanthate Ethyl S-ethyl xanthate... 

Condensation of 1 in ethanol with potassium ethylxanthate gave210 the crystalline O-ethyl S-glycosyl xanthate 63 (R = Et) in high yield on treatment with cold methanolic ammonia, the compound underwent O- and S-deacetylation and 1 actonization, to give a hygroscopic product to which structure 64 has been ascribed. Treatment of 64 with diazomethane, followed by acetylation, resulted in the known201 1-thioglycoside derivative 61 (R = Me). 

L-Proline and tert-hutyl S-ethyl xanthate dissolved in aq. 50%-dioxane at pH 7-8, and the product isolated after 12 hrs. at room temp. -> product. Y 79%. - Prim, and sec. alkyl xanthates give thionourethans. F. e., also without solvent, s. G. C. Barrett and C. M. O. A. Martins, Chem. Commun. 1972, 638. 

All reactions of benzotriazole derivatives of the type Bt-CR RbS discussed above are based on electrophilic or nucleophilic substitutions at the ot-carbon, but radical reactions are also possible. Thus, the first report on unsubstituted carbon-centered (benzotriazol-l-yl)methyl radical 841 involves derivatives of (benzotriazol-l-yl)methyl mercaptan. 3 -(Benzotriazol-l-yl)methyl-0-ethyl xanthate 840 is readily prepared in a reaction of l-(chloromethyl)-benzotriazole with commercially available potassium 0-ethyl xanthate. Upon treatment with radical initiators (lauroyl peroxide), the C-S bond is cleaved to generate radical 841 that can be trapped by alkenes to generate new radicals 842. By taking the xanthate moiety from the starting material, radicals 842 are converted to final products 843 with regeneration of radicals 841 allowing repetition of the process (Scheme 134). Maleinimides are also satisfactorily used as radical traps in these reactions <2001H(54)301>. 

The FTIR reflection spectra of ethyl xanthate, and iron ethyl xanthate were reported to show the following characteristic absorption bands of ethyl xanthate the stretching vibration bands of the C—O—C at 1100- 1172 cm and C==S at 1049 cm and 1008 cm". When dixanthogen was formed, the stretching vibration bands changed. The characteristic absorption bands are 1260 cm" , 1240 cm", 1020 cm" and 1105 cm". When iron ethyl xanthate was formed, the stretching vibration band of C=S shifted to 1029 cm" and 1005 cm" (Mielezarski, 1997 Leppinen, 1990). 

It was reported that when lead ethyl xanthate was formed, the stretching vibration band of C=S shifted to 1018 and 996 cm . The stretching vibration band of C—O—C shifted to 1112 and 1207 cm" (Leppinen, 1990). 

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... 

Finkelstein, N. P., 1999. Addendum to The activation of sulphide minerals for flotation a review. Inter. J. Miner. Process, 55(4) 283 - 286 Fomasiero, D., Montalti, M., Ralston, J., 1995. Kinetics of adsorption of ethyl xanthate on pyrrhotite in situ UV and infiared spectroscopic studies. Langmuir, 11 467 - 478 Forssberg, K. S. E., Antti, B. M., Palsson, B., 1984. Computer-assisted calculations of thermodynamic equilibria in the chalcopyrite-ethyl xanthate system. In M. J. Jones and R. Oblatt (eds.). Reagents in the Minerals Industry. IMM, Rome, Italy, 251 - 264 Fuerstenau, M. C., Kuhn, M. C., Elgillani, D. A., 1968. The role of dixanthogen in xaomthate flotation ofpyrite. Trans. AIME, 241 437 Fuerstenau, M. C. and Sabacky, B. J., 1981. Inter. J. Miner. Process, 8 79 - 84 Fuerstenau, M. C., Misra, M., Palmer, B. R., Xanthate adsorption on selected sulphides in the presence of oxygen. Inter. J. Miner. Process... 

Pozzo, R. L., Malicsi, A. S., Iwasaki, L, 1988. Pyrite-pryyhotite-grinding media contact and its effect on flotation. Minerals Metallurgical Processing, 5(1) 16-21 Pozzo, R. L., Malicsi, A. S., Iwasaki, I., 1990. Pyrite-pyrrhotite-grinding media contact and its effect on flotation. Minerals Metallurgical Processing, 7(1) 16 - 21 Prestidge, C. A., Thiel, A. G., Ralston, J., Smart, R. S. C., 1994. The interaction of ethyl xanthate with copper (II)—activated zinc sulphide kinetic effects. Colloids Surfece, A. Physicochem. Eng. Aspects, 85 51 - 68... 

Woods, R., Basilio, C. I., Kim, D. S., Yoon, R. H., 1994. Chemisorption of ethyl xanthate on silver-gold alloys. Colloids and Surfaces A Physicochemical and Engineering Aspects, 83(1) 1-7... 

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