THE CHEMICAL STABILITY OF THE S-METHYL XANTHATES OF SOME SIMPLE ALCOHOLS

Abstract

11-Octadecyl S-methyl xanthate, m.p. 38-39", and n-hexadecyl S-methyl xanthate, m.p. 2&28.5", were prepared for the hrst time, and were used to study the behavior of the S-methyl xanthale group toward reagents commonly used in research on carbohydrates. Although stable to some conditions of acetylation, hydrolysis, and methanolysis, the S-methyl xanthate group was destroyed by all methylating agents tried, with the exception of nitrosornethylurethane. The latter reagent converted a sodium xa~lthate salt in high yield to the S-methyl ester. Octadecyl and hexadecyl S-methyl xanthates when oxidized with hydrogen peroxide yielded crystalline substances of conlposition C?oH4oO4S~ and C I~H~G O~S ? , respectively, whose structures were not determined. These substances each contained three additional oxygen atoms. Various attempts to estimate the S-methyl xanthate group by oxidation with bromine or periodic acid, or by reduction to methyl iodide, were unsuccessful. INTRODUCTIONAs a preliminary to research on xanthates of carbohydrates, it seemed desirable to investigate some simple, crystalline derivative of the xaiithate group that was more stable than a free xanthic acid or its alkali salt toward reagents frequently used in carbohydrate chemistry. Xanthate-S-methyl esters a t once came into consideration, because they could be formed in high yield bj-the action of methyl iodide on a suitable salt. The term "xanthate ester" referred to a double ester such as C2HjOCSSC?H5, whose formal name was ethyl ethoxymethanethionothiolate, but which could be more clearly described as 0-ethyl S-ethyl xanthate (6).Simple xanthate esters were usually high-boiling liquids, and of the Smethyl compounds oiily eight were reported as crystalline. All eight were derived from aromatic, hydroaromatic, and terpene alcohols, and their carbon sltcletons were uniiccessarily complicated for the purpose in view. Nevertheless, the S-methyl xanthates oi benzyl and hexahydrobenzyl alcohol, and of menthol, were prepared for reference purposes. Whitmore and Simpson's modification (25) of tlie long-neglected Zeise (27) "one-step" process employing tlie alcohol, solid sodiurn hydroxide, carboll disulphide, and later methyl iodide, was used. The melting point of the hesahydrobenzyl derivative was confirmed as 16.5", apparently the value given by Aleltsandrovich ( I ) , and not as 1 Go, as misquoted by Chemical Abstracts and British Chemical Abstracts.The same general method was used to synthesize several S-methyl xanthates of nornial aliphatic alcohols in 60-8070 yield. I t transpired that the octyl derivative mas a liquid, and that the S-methyl xanthates of n-hexadecyl (cetyl) and ?z-octadecyl (stearyl) alcohol were crystalline solids whose melting 'il[anz~script received ilfay 28, 1956.

Some reactions of alkoxythiocarbonyl derivatives with N,N-dimethylhydrazine

“…with D,O, NH); m/z 149 (MH"), 148 (M'), 107,106,60, and 59. The spectral properties of a sample of (11) prepared by the literature method were identical with those reported above.…”