Dithiolate salt

Attempts to follow a published procedure for the preparation of 1,3 -dithiole-2-thione-4,5-dithiolate salts [1], involving reductive coupling of carbon disulfide with alkali metals, have led to violent explosions with potassium metal, but not with sodium [2], However, mixtures of carbon disulfide with potassium-sodium alloy, potassium, sodium, or lithium are capable of detonation by shock, though not by heating. The explosive power decreases in the order given above, and the first mixture is more shock-sensitive than mercury fulminate [3],... 

In the former case, the dibromo- or dichloro-substituted arene is reacted with cuprous or sodium thiolates to give vicinal thioethers, which can be reductively dealkylated, for example with Na/NH3, to give the dithiols.63 Alternatively, benzenethiol is reacted with ra-BuLi, and the resulting lithiated product is made to react with elemental sulfur to give the 1,2-dithiolate salt. 

Reaction of disodium dithiolate salt 349 with phenacyl bromide affords 350. Treatment of the latter with Lawesson s reagent (LR) gives 351 (Scheme 28) <1996TL2821>. 

Dithiole-2-thione-4,5-dithiolate salts, 112 Drums (barrels), 112... 

Bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET) was first synthesized in 1978, starting from dithiolate salt (6) [20]. The l,3-dithiole-2-... 

Oxa- and l-thia-4,6-dioxa- and -4,6-dithiastannocanes 389, 390, 392 and 393 were prepared by similar methods from the respective organotin halides or SnHaLj and diolate or dithiolate salts D(CH2CH2ZNa)2 (D = O Z = O, S) l - 20... 

Another macrocyclic family (22)-(26) was made by reacting 3,6-dichloropyridazine with the corresponding potassium dithiolate salt in ethanol under highly diluted conditions.51,52... 

Dihalophthalazines or their derivatives are very similar in reactivity to the corresponding 3,6-dihalopyridazines, i.e., they can react with active H atoms either on N, S, or C atoms. (57)-(60) (Scheme 15) were made from the reaction of 1,4-dichlorophthalazine with the corresponding dithiol salts adopting the same method as employed for making related pyridazine macrocycles.48-50 54... 

Two efficient syntheses of strained cyclophanes indicate the synthetic potential of allyl or benzyl sulfide intermediates, in which the combined nucleophilicity and redox activity of the sulfur atom can be used. The dibenzylic sulfides from xylylene dihalides and -dithiols can be methylated with dimethoxycarbenium tetrafiuoroborate (H. Meerwein, 1960 R.F. Borch, 1968, 1969 from trimethyl orthoformate and BFj, 3 4). The sulfonium salts are deprotonated and rearrange to methyl sulfides (Stevens rearrangement). Repeated methylation and Hofmann elimination yields double bonds (R.H. Mitchell, 1974). 

The reaction of toluene-3,4-dithiol(3,4-dimercaptotoluene) and antimony trichloride ia acetone yields a yeUow soHd Sb2(tdt)2, where tdt is the toluene-3,4-dithiolate anionic ligand (51). With the disodium salt of maleonitnledithiol ((Z)-dimercapto-2-butenedinitrile), antimony trichloride gives the complex ion [Sb(mnt)2] , where mat is the maleonitnledithiolate anionic ligand. This complex has been isolated as a yeUow, crystalline, tetraethyl ammonium salt. The stmctures of these antimony dithiolate complexes have apparendy not been unambiguously determiaed. 

Alkylisothiazolium salts (61) undergo N—S bond cleavage when treated with hydrogen sulfide or thiophenol to form acyclic products (62), but 2-aryl compounds give 1,2-dithioles (63 or 64 Scheme 9) (75SST(3)54l, 77SST(4)339). 

Sodium or potassium hydrogen sulfite reacts with several thiiranes to give disulfides of /3-mercaptosulfonic acid salts (76EGP122086). Potassium thiocyanate in dimethylformamide or aqueous ethanol isomerizes thiiranes (Scheme 84) (72CJC3930). 1,2-Dithiols are obtained by treatment of thiiranes with NaBH2S3 obtained from sodium borohydride and sulfur (73TL1401). 

Dithiole-3-sulfonyl hydrazides alkali metal salts,... 

A carbonyl group can be protected as a sulfur derivative—for example, a dithio acetal or ketal, 1,3-dithiane, or 1,3-dithiolane—by reaction of the carbonyl compound in the presence of an acid catalyst with a thiol or dithiol. The derivatives are in general cleaved by reaction with Hg(II) salts or oxidation acidic hydrolysis is unsatisfactory. The acyclic derivatives are formed and hydrolyzed much more readily than their cyclic counterparts. Representative examples of formation and cleavage are shown below. 

Quite a number of mixed sulfur-nitrogen macrocycles have been prepared, but these have largely been by the methods outlined in Chaps. 4 and 5 for the respective heteroatoms. An alternative method, involves the formation of a Schiff base, followed by reduction to the fully saturated system, if desired. An interesting example of the Schiff base formation is found in the reaction formulated in (6.12). Dialdehyde 14 is added to ethylenediamine in a solution containing ferrous ions. Although fully characterized, the yield for the reaction is not recorded. To avoid confusion with the original literature, we note the claim that the dialdehyde [14] was readily prepared in good yield by reaction of the disodium salt of 3-thiapentane-l, 5-diol . The latter must be the dithiol rather than the diol. 

Thiophenedithiol (170) has been prepared by halogen-metal interconversion between the lithium salt of 4-bromo-3-thiophenethiol and n-butyllithium at —70°C, followed by reaction with sulfur/ IR, NMR, and UV spectra showed that this compound exists in the dithiol form (170). The compound obtained as a by-product in the... 

Reaction of disodium salt of pyridine-2,3-dithiol (385) with l-chloro-2-nitrobenzene provided in 45% yield the corresponding aza analog 386 (82JHC1441). Similar treatment with 2-chloro-3-nitropyridine (193) provided... 

Dithiol is a less selective reagent than thiocyanate for molybdenum. Tungsten interferes most seriously but does not do so in the presence of tartaric acid or citric acid (see Section 17.34). Tin does not interfere if the absorbance is read at 680 nm. Strong oxidants oxidise the reagent iron(III) salts should be reduced with potassium iodide solution and the liberated iodine removed with thiosulphate. 

Discussion. In acid solution, toluene-3,4-dithiol (dithiol) forms a red compound when warmed with tin(II) salts (compare molybdenum, Section 17.30). Tin(IV) also reacts, but more slowly than tin(II) thioglycollic acid may be employed to reduce tin(IV) to tin(II). The reagent is not stable, being easily reduced, and hence should be prepared as required. A dispersant is generally added to the solution under test. 

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