Dithiocarbonic acid ester

Classification Dithiocarbonic acid ester Empirical C3H6OS2... 

Synonyms Butyl potassium xanthate Butyl xanthic acid, potassium salt Carbondithioic acid, O-butyl ester, potassium salt Dithiocarbonic acid-o-butyl ester potassium salt Potassium o-butyl carbonodithioate Potassium butyl xanthate Potassium-o-butyl xanthate Potassium butyl xanthogenate Potassium xanthogenate butyl ether Classification Potassium salt of dithiocarbonic acid ester... 

Classification Potassium salt of dithiocarbonic acid ester... 

Synonyms Carbonodithioic acid, 0-(2-methylpropyl) ester, sodium salt Dithiocarbonic acid, 0-isobutyl ester, sodium salt Isobutyl xanthic acid, sodium salt SIBX Classification Sodium salt of a dithiocarbonic acid ester... 

N-acyldithiocarbazic acid esters Dithiocarbonic acid esters (s.a. Imino-dithiocarbonic acid esters)... 

Alkyl S-carbalkoxy xanthates a-Arylthio-a,P-oxidosulfones Dithiocarbonic acid esters a,P-Ethylene-a-sulfinylsulfones P-Sulfoniosulfonic acid betaines Thionothiodiformic acid esters... 

Xanthate zan- that (1831) n. A sodium salt of a dithiocarbonic acid ester, in particular the one formed in the viscose-rayon process by the reaction between sodium hydroxide cellulose and carbon disulfide and having the structure shown below, called cellulose xanthate or viscose. The viscose is subsequently precipitated, filtered, extruded as... 

Polysaccharides react with carbon disulfide and sodium hydroxide to give dithiocarbonic acid esters known as xanthates ... 

Xanthate n zan- that n (1831) A sodium salt of a dithiocarbonic acid ester, in particular the one formed in the viscose-rayon process by the reaction between sodium hydroxide cellulose and carbon disulfide and having the structure shown below, called cellulose xanthate or viscose. The viscose is subsequently precipitated, filtered, extruded as filaments into dilute sulfuric acid, washed, and dried to make viscose that be spun into Rayon fabric, and extruded thin sheets are called Cellophane . (Kadolph SJJ, Langford AL (2001) Textiles. Pearson Education, New York Ash M, Ash I (1982-1983) Encyclopedia of Plastics, Polymers, and Resins, Vols. I-in. Chemical Publishing, New York). 

Polysaccharides react with carbon disulfide and sodium hydroxide to give dithiocarbonic acid esters called xanthates. The polysaccharide, such as cellulose, is first treated with 18% sodium hydroxide to give alkaline cellulose (reaction 7.4). The alkaline cellulose is usually aged several hours to achieve lower d.p. values. It is then reacted with carbon disulfide for 1-3 hr at 20-30°C (reaction 7.4). 

The xanthates react with alkyl halides to give the di-esters of dithiocarbonic acid 0=C(SH)2 S=C(SH)0H, for example ... 

The anionic species ROCS2 resulted from O-alkyl(aryl) esters of the hypothetical dithiocarbonic acids, ROC(S)SH, better known as xanthates, are versatile ligands and they generate an extensive coordination chemistry. The interest for metal xanthates is stimulated by their potential use as single source precursors for nanoscopic metal sulfides in photochemical or thermal vapor deposition systems under mild conditions,218 221 e.g. for Zn,222 Cd,223 In,224... 

In the presence of potassium hydroxide, cellulose adds to carbon disulfide (Figure 8.4). In this way potassium xanthate A is produced. It is soluble in water, but restores the water-insoluble cellulose upon addition of acid. The primary protonation product is the dithiocarbonic acid O-cellulose ester B. B reacts just like the unstable carbonic acid derivatives in Figure 8.3, namely via a zwitterion (C) and its decomposition into cellulose (a heteroatom nucleophile)... 

In Figure 4.14, we learned about the Chugaev elimination in connection with the synthesis of alkenes. The second (primary) product of this reaction is the dithiocarbonic acid 5-methyl ester (A). It equilibrates with the zwitterion B, which decomposes into carbon oxysulfide (a heterocumulene) and methanethiol (a heteroatom nucleophile). 

Carbon disulfide is the dithio derivative of C02. It is only a weak electrophile. Actually, it is so unreactive that in many reactions it can be used as a solvent. Consequently, only good nucleophiles can add to the C—S double bond of carbon disulfide. For example, alkali metal alkoxides add to carbon disulfide forming alkali metal xan-thates A (Figure 7.4). If one were to protonate this compound this would provide compound B, which is a derivative of free dithiocarbonic acid. It is unstable in the condensed phase in pure form, just as free carbonic acid and the unsubstituted carbamic acid (Formula B in Figure 7.3) are unstable. Compound B would therefore decompose spontaneously into ROH and CS2. Stable derivatives of alkali metal xanthates A are their esters C. They are referred to as xanthic add esters or xanthates. They are obtained by an alkylation (almost always by a methylation) of the alkali metal xanthates A. You have already learned about synthesis applications of xanthic acid esters in Figures 1.32, 4.13, and 4.14. 

The mixed esters of carbonic acid [see Table I, type (a)] were formerly designated carboalkyloxy, but this term is now avoided, since it was often confused with carboxyalkyl [—(CHj) —CO2H]. A, the mixed esters of dithiocarbonic acid [see Table I (e) R = alkyl] have been termed alkyl xanthogenates or alkyl xanthates, thus relating them to the corresponding acid dithiocarbonates (R = metal), industrially called xanthates, but more precisely termed 0-(/Si-metal thiolthiocarbonyl) derivatives. Of the mixed-ester types and acid types indicated in Table I, examples of (a), (b), (e), (f), and (g) of the former, and (a), (b), and (e) of the latter have so far been reported. For intermolecular esters, examples of (i) and (k), and, for cyclic esters, examples of (0) and (t), have been described. 

Alkyl(aryl) thiocarbonates (xanthates) are (9-alkyl(aryl) esters of the hypothetical dithiocarbonic acid, HSC(S)OH.174,175 These esters are unknown in the free state and only their alkali metal salts, M[S2COR], are readily available, and stable enough to be used as starting materials for metal complexes. Alkyl(aryl) dithiocarbonates (xanthates) were discussed in CCC (1987) and continued to be used as ligands, with some interesting new results being reported. 

Urethanes or dithiocarbonic acid amides are cyclization agents which, with sodium hydride as a base, convert 2-aminonicotinic acid esters into pyrido[2,3-[Pg.98]

The amide of dithiocarbonic acid is dithiocarbamic acid, which similarly occurs only in the form of its salts and mainly its esters. In the general formula of these dithiocarbamates (2) three substitutions are possible. 

Dithiocarbonic acid-o-butyl ester potassium salt. See Potassium n-butyl xanthate... 

Dithiocarbonic acid, O-butyl ester, sodium salt. See Sodium n-butyl xanthate Dithiocarbonic acid, O-s-butyl ester, sodium salt. See Sodium s-butyl xanthate Dithiocarbonic acid, O-ethyl ester. See Ethyl xanthate... 

Dithiocarbonic acid, O-isopropyl ester, sodium salt. See Sodium isopropyl xanthate Dithiocarbonic acid, 0-pentyl ester, potassium salt. See Potassium amyl xanthate Dithiocarbonic anhydride. See Carbon disulfide Dithiodemeton. See Disulfoton P,P-Dithiodialanine. See L-Cystine N,N -(Dithiodicarbonothioyl) bis (N-methylmethanamine). See Tetramethylthiuram disulfide... 

Synonyms Carbonodithioic acid, 0-ethyl ester Dithiocarbonic acid, 0-ethyl ester Ethyixanthic acid Ethyl xanthogenate... 

Synonyms Amyl potassium xanthate Carbonic acid, dithio-, 0-pentyl ester, potassium salt Carbonodithioic acid, 0-pentyl ester, potassium salt Dithiocarbonic acid, 0-pentyl ester, potassium salt KAX PAX Pentyl xanthic acid, potassium salt Potassium amyixanthogenate Potassium n-amylxanthogenate Potassium pentyl xanthate Potassium pentyl xanthogenate Xanthic acid, pentyl-, potassium salt Empirical CeHiiKOS2 Formula C4H9CH20C(S)S"K"... 

Potassium ethyl xanthate CAS 140-89-6 EINECS/ELINCS 359-697-4 Synonyms Carbonodithioic acid, 0-ethyl ester, potassium salt Dithiocarbonic acid, 0-ethyl ester, potassium salt (0-Ethyl dithiocarbonato) potassium Ethyl potassium carbonate Ethyl potassium xanthate... 

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