Dimethyl disulfur

When deprotonated dimethyl sulfone is reacted with 2 equiv of benzonitrile, compound 109 is obtained in low yield (Equation 91) <1973JOM(59)53>. Compounds of the general structure 179 can be prepared from two molecules of enamino esters 288 and sulfur dichloride or disulfur dichloride <1984JOG4780> or in low yield using chlorocarbo-nylsulfenyl chloride 289 as the source of sulfur <1985JHC1621> (Equation 92). A series of cycloadditions lead to the formation of 131 from 290 and two molecules of the ynamine 291 (Scheme 69) <1995LA1795>. 

Two other approaches beside Bergson s have been used to derive torsion barriers for S—S bonds namely, from the torsional frequency of the bond as observed in Raman spectra, and from measured thermodynamic data as compared with statistically calculated ones. According to Scott and coworkers the torsional frequencies in dimethyl disulfide (204), diethyl disulfide (205), and disulfur dichloride (139) correspond to barrier heights of 9.5, 13.2, and 14.2 kcal/mole, respectively. On the other hand, agreement between calculated and observed entropy and heat capacity of dimethyl disulfide was obtained (146) by use of 6.8 kcal/mole for the effective barrier height. From observed and calculated heat capacities, Feh r and Schulze-Rettmer (76) arrived at a value of 2.7 kcal/mole for the barrier height in hydrogen disulfide. 

Poly (S-leucinato-AT, 0) cobalt (III) -u- [3,3 -dithiobis (2,4-pentanedion-ato-0,0 )]).—Initially, 1.7460 g disulfur dichloride (12.93 mmol) in 6 mL dry dichloroethane was added dropwise to 5.0088 g Co(leu)(acac)2 (12.93 mmol) in 20 mL dimethylacetamide (DMAC) with 0.7095 g sodium carbonate (6.69 mmol) as a slurry in the dimethylacetamide solution under argon and with vigorous stirring. The mixture was stirred for 24 - 36 h and then precipitated with diethyl ether. Alternatively, the solvent was removed in vacuo at 45 C. The product was collected on a fritted funnel, washed with water, and dried in vacuo at lOO C yield, 5.5 g 95%. The polymer was fractionated (three times) by a DMAC/acetone or dimethyl sulfoxide/acetone solvent/nonsolvent precipitation to remove low molecular-weight material. 

Related Reagents. Benzenesulfenyl Chloride 2-(Methyl-thio)- li/-isoindole-1,3(2/ -dione N- ferf-Butylthiophthalimide 7V-Phenylthiophthaliinide Dimethyl(methylthio)sulfoniumTetra-fluoroborate Ethyl Thiosulfinate Disulfur Dichloride. 

In the reaction of the tropothione -sulfide 34, obtained from tropone hydrazone and disulfur dichloride, at -78 °C in the presence of dimethyl acetylenedicarboxylate, the [IOtt + 7t] cycloadduct 35 was obtained in 23 % yield... 

Sulfuric acid dimethyl ester) see Dimethyl sulfate Sulfur monochloride (Sulfur chloride or Disulfur dichloride) 10025-67-9 TCx... 

---