Ethylene trithiocarbonate

Carbon disulfide reacts with ethylene oxide to give ethylene trithiocarbonate (90), and isocyanates yield derivatives of 2-oxazohdinone (91). 

Thiocarbonyl compounds can be converted into difluoromethylene compounds usually under milder conditions than the conesponding carbonyl compounds Ethylene trithiocarbonate reacts smoothly with sulfur tetrafluoride at 110 °C in the absence of catalyst to give 2,2-difluoro-l,3-dithiolane in high yield. Thiuramsul/ides under similar conditions are readily converted into dialkyItrifluo-rometkylamines [11] (equations 13 and 14). 

Unexpectedly, upon reacting commercially available ethylene trithiocarbonate 111 with benzyne, the salt 103a was obtained as the major product along with a small amount of l,3-benzodithiole-2-thione 109a, as shown in Equation (31) <1996CC205> and <1996BCJ2349>. 

Alternatively, l,3-dithiol-2-ones have been obtained by reacting di-isopropylxanthogen disulfide with unsaturated substrates, such as disubstituted alkynes R2C2, in the presence of AIBN (azoisobutyrylnitrile), a radical initiator.78 Finally, vinylene dithiocarbonates can be obtained by reacting mer-cury(II) acetate with the corresponding trithiocarbonates, generated by reaction of electrophilic alkynes with ethylene trithiocarbonate.79 Analogously,... 

Simple large scale syntheses of 4-hydroxythiocoumarin and 2-methylthiochromone from 2-mercaptobenzoic acid have been devised <00SC1193> and efficient syntheses of various simple and fused thiopyran-4-ones and 4-thiones have been achieved through the reaction of ethylene trithiocarbonate and dibenzoylacetylene (Scheme 58) <00JCS(P1)1467>. 

Benzo[7]thiete 41 reacts in the ortho-qumoiA isomer 41 with cyclic trithiocarbonates such as l,3-dithiolane-2-thione, (ethylene trithiocarbonate), l,3-dithiole-2-thiones, and adamantanethione <1997LA1603>. In boiling toluene, 1,3 dithiolane and dithiole derivatives formed the spiro compound 42 and 43 in good yield. The related l,3-dithiole-2-thiones reacted chemoselectively at the C=S double bond. The use of adamantanethione yielded the polycyclic adduct 44 in a smooth and quantitative reaction (Scheme 3). 

Ethylene sulphide and propylene sulphide have been reported by Soga et ol. [249,250] to copolymerise with carbon disulphide in the presence of catalysts such as diethylzinc, diethylcadmium and mercury bis( -butanethiolatc), yielding poly(alkylene thioether-trithiocarbonate) copolymers (Table 9.4). The content of ethylene trithiocarbonate units in the ethylene sulphide/carbon disulphide copolymer obtained with the most efficient catalyst, mercury bis( -butanethiolate), was in the range 50-70 mol.-% [249]. 

In order to clarify the mechanism, the reaction of carbon disulphide with mercury bis(n-butanethiolate) was studied. On the basis of results obtained, it was suggested that this reaction involved the formation of a coordination complex, followed by the formation of active species containing the Hg-SC(S) bond. Moreover, the cyclic trithiocarbonate, ethylene trithiocarbonate, found to be present in trace amounts in copolymerisation products, was excluded as a possible intermediate for the copolymer formation, since it did not undergo any polymerisation under the given conditions [249],... 

Furthermore, alkynes bearing electron-withdrawing substituents react with 0,5-ethylene dithiocarbonate or ethylene trithiocarbonate giving ethylene and l,3-dithiol-2-ones (338 X = 0) or l,3-dithiole-2-thiones (338 X = S), respectively (74JOC2456, 72JCS(pl)4l,... 

In 1974 a multistep synthesis of TTF was published that starts from a readily available starting material, ethylene trithiocarbonate (2), and af-... 

Ethylene trithiocarbonate is reduced in DMF to the radical anion, which loses ethylene [294] the reaction is akin to other reductive elimination reactions. The sulfur-containing part reacts with another anion radical to a bis(trithiocarbonate) dianion. 

In contrast to the facile formation of ethylene trithiocarbonate (52) by the reaction of ethylene dibromide with sodium trithiocarbonate as shown in Equation (10) and Scheme 9, the major course of the reaction of ethylene dibromide with the selenodithiocarbonate ion (53) <71ZAAC(384)235> has been reported to lead to the precipitation of red selenium (75%), accompanied by the vigorous evolution of ethylene, and the expected thiaselenoranethione (54) was obtained only in 2% yield. The reaction process can be rationalized by assuming that the initially formed monoalkylated anion (55) is in equilibrium with carbon disulfide and the /i-bromoethylselenide ion (56) the latter can rapidly cyclize to the extremely thermolabile ethylene episelenide (1). 

Figure 3.2. Absorption spectrum of ethylene trithiocarbonate in different solvents2- ...

Bis(methylcarboxy)-l,3-with dimethyl acetylenedicarboxylate in tolume at reflux temperature. Methylcarboxyl- l,3-dithiole-2-thione(3)[1031 and selenium-ana-log (4) [l()4],have been prepared by treatment of ethylene trithiocarbonate and selenium analog, respectively, with methyl propiolate in toluene at reflux temperature for several hours followed by silica gel coliunn chromatography separation (CgHg-cyclohexane 1 1). 

A high-pressure shaker vessel lined with Hastelloy stainless steel charged with ethylene trithiocarbonate and a little over 2 moles of sulfur tetrafluoride heated 8hrs. at 110° 2,2-difluoro-l,3-dithiolane. Y 82%. F. e. s. R. J. Harder and W. C. Smith, Am. Soc. 83, 3422 (1961). 

Dithioesters have been studied by several workers [49, 77, 78] and there is general agreement that these absorb between 1225— 1190cm-. Trithiocarbonates absorb at lower frequencies [48] with ethylene trithiocarbonate at 1083 cm-. Xanthates have a series of bands in the ranges 1250—1200, 1140—1110, and 1070— 1020 cm-. All have some C=S content but none of them can be xmequivocably assigned to this structure. 

The C=S group in ethylene trithiocarbonate has a C=S stretch band at 1064 cm" as seen in spectrum 218 in Ch. 13. This can be compared with the C=0 stretch in ethylene carbonate at 1804 cm in spectrum 217 in Ch. 13. In both cases, the high frequency C=X group is attached to two low frequency C—X groups. This means that the single bonded X atoms are nearly stationary, dius isolating the double bond vibration. 

Oxidation of internal acetylenes with ruthenium tetroxide gives the corresponding diketones with some of the acids resulting from cleavage. DMAD reacts with ethylene trithiocarbonate (134) to give ethylene and the l,3-dithiole-2-thione (135). Further study has indicated that acetylenes... 

The reaction of ethylene trithiocarbonate with dimethyl acetylenedicarboxylate has been modified so as to provide useful syntheses of the l-selena-3-thiole-2-selone (40 R = C02Me, X = S, Y = Z = Se), the l,3-diselole-2-selone (40 R = COaMe, X = Y = Z = Se), and other analogues. ... 

Treatment of 4,5-bis(methylthio)-l,3-dithiole-2-thione (21) with morpholine gave a complex mixture of products among which was a mixture of cis- and trans-thiirans (22), obtained in moderate yield. A thiiren intermediate was suggested. Photolysis of ethylene trithiocarbonate produces... 

Condensation reactions yielding cyclic and/or linear oligosulfides were studied by four research groups [89-93]. In 1863, Husemann [89] prepared an intermediate by condensation of 1,2-dibromoethane with sodium sulfide. By heating he obtained the cyclic dimer, dithiane, as a volatile degradation product. Mansfeld [90] reinvestigated this reaction and interpreted the intermediate as polymer, but he speculatively assigned the formula of a cyclic trimer. Husemann also prepared poly(methylene sulphide) from dibromomethane and sodium sulfide. Furthermore, he performed condensations of dibromomethane and dibromoethane, respectively, with sodium trithiocarbonate, which was easily obtained from sodium sulfide and carbon disulfide. He isolated a five-membered cyclic ethylene trithiocarbonate, but a polymeric methylene trithiocarbonate the molar mass of which remained obscure. 

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