This reaction is the reverse of the method for the preparation of the xanthate salts. A closely related potassium ethyl xanthate (KEX) is obtained as the anhydrous salt. Sodium ethyl xanthate is a pale yellow powder. Sodium ethyl xanthate (SEX) is an organosulfur compound with the chemical formula CHCHOCSNa. Potassium ethyl xanthate (KEX) is an organosulfur compound with the chemical formula CHCHOCSK. In the viscose process, cellulose is made soluble by conversion to its xanthate derivatives. Potassium xanthate is a useful reagent for preparing xanthate esters from alkyl and aryl halides. A more controlled elimination reaction requires the formation of the xanthate ester. Unlike the related sodium ethyl xanthate, the potassium salt exists as an anhydrous salt. Sodium ethyl thioxanthate is similar structurally to sodium ethyl xanthate. Condensation with xanthate esters affords mercaptoimidazoles, which are used as antioxidants in rubber products. The Chugaev elimination is the pyrolysis of a xanthate ester, resulting in an olefin. With the addition of iodomethane, the alkoxide is transformed into a methyl xanthate. This viscous liquid was then passed through granulators to grind up the chunks of xanthate. For example, sodium ethoxide gives sodium ethyl xanthate.