Carbon disulfide reagent

A further consequence of association of acylating agents with basic compounds is an increase in the bulk of the reagent, and greater resistance to attack at the more stericaHy hindered positions of aromatic compounds. Thus acylation of chrysene and phenanthrene in nitrobenzene or in carbon disulfide occurs to a considerable extent in an outer ring, whereas acylation of naphthalene leads to extensive reaction at the less reactive but stericaky less hindered 2-position. 

The most important hazard ia the manufacturiag of xanthates is the use of carbon disulfide (qv) because of its low flash poiat, ignition temperature, and its toxicity. A report on the manufacture of sodium ethyl xanthate at Keimecott Nevada Mines Division discusses the various safety problems and the design of a faciUty (81). A plant layout and a description of the reagent preparations are also given. 

Carbon disulfide reacts with Grignard reagents to prepare the corresponding dithiocarboxyHc acids ... 

Modem plants generally produce carbon disulfide of about 99.99% purity. High product quaUty is ensured by closely controlled continuous fractional distillation. Reagent and U.S. Federal specifications, and typical commercial-grade quaUty are Hsted in Table 5. 

A number ot aryl trifluoromethyl ethers are synthesized by fluormation of aryl chlorothioformates with molybdenum hexafluoride. The reagents are progressively heated from -25 to 130 C, and the products are distilled off. Molybdenum disulfide and carbon disulfide are the by-products [12] (equation 16)... 

DeoxygendQon from rutro ilkdnes is possible by other vanous reagents, including TiCU," Me-Sil, carbon disulfide in the presence of base, Me-SiSiMe-., " andSnfSPhij-PhSH-Et-jN fEq 6 62)... 

A few chemicals are based on the direct reaction of methane with other reagents. These are carbon disulfide, hydrogen cyanide chloromethanes, and synthesis gas mixture. Currently, a redox fuel cell based on methane is being developed. ... 

Hydrazine 835 underwent ring closure with one carbon cyclizing reagents to afford 837 and/or /V-acyl derivatives 836. The N-acyl derivatives underwent cyclization on treatment with phosphorus oxychloride. They were also prepared by the reaction of hydrazones 838 with thionyl chloride (84JHC1565). Compound 835 underwent ring closure with carbon disulfide and ethyl chloroformate to give 839 (Scheme 169). 

After refluxing, disconnect the trapping tube, and transfer the yellow solution into a 25-mL volumetric flask. Rinse the mbe with ethanol, and adjust the solution to volume with ethanol. Measure the absorbance of the solution at 435 nm against a blank prepared by diluting 15 mL of color reagent to 25 mL with ethanol. Determine the carbon disulflde content from a calibration curve obtained by plotting carbon disulfide concentrations of different standard solutions on the abscissa versus the absorbance on the ordinate. 

Deoxygenation from nitroalkanes is possible by other various reagents, including TiCl3,119 Me3SiI,63 carbon disulfide in the presence of base,120 Me3SiSiMe3,121 and Sn(SPh)2-PhSH-Et3N (Eq. 6.62).122... 

The complex also undergoes a variety of addition reactions with reagents such as methyl iodide, hydrochloric acid, benzoyl chloride, and allyl chloride.8 In a reaction similar to that of the decarboxylation of aldehydes, the complex will abstract CS from carbon disulfide to give the irans-thiocarbonyl complex rans-RhClCS[P(C8H6)5]2.9... 

Phosphorus pentasulfide is used to replace oxygen atoms with sulfur atoms the reaction is commonly carried out in a solvent heated under reflux. Solvents employed include carbon disulfide, aromatic hydrocarbons, and pyridine. If an oxygen atom is part of a heterocycle, then the reagent may replace it with sulfur, as in the formation of 2,1-benzisothiazoles from 2,1-benzisoxazoles.119 Such replacements are, however, not general some prior ring opening appears to be necessary before the reagent can act. For example, under normal conditions furan is not attacked. 

The thiadiazolopyrimidine derivative 39 reacts with ethoxycarbonyl isothiocyanate and carbon disulfide. In the former case the bicyclic derivative 40 is formed, and with the latter reagent the pyrimido dithiazole 41 is formed (Scheme 4) <2004JHC99>. 

Dithioacids have been generated from carbon disulfide with Grignard reagents or alkyl lithium at 0 °C. Subsequent treatment with sulfonamide in situ gives the corresponding both aliphatic as well as aromatic thioamides in 70-90% yields (Scheme 10).31... 

The free dithiocarboxylic acids can be isolated, but their salts are preferred. In some cases their metal complexes can be prepared directly by insertion of carbon disulfide into metal-carbon bonds. Thus, the reaction of Grignard reagents, RMgX, with CS2, followed by acid treatment gives the dithiocarboxylic acids RCSSH and metal complexes in good yields.311... 

Transformation of the thiadiazolopyrimidine compound 138 to the fused dithiazole 140 also follows a fairly complicated pathway <2004JHC99>. When the derivative 138 is treated with carbon disulfide, a cyclization reminiscent of 1,3-dipolar cyclization takes place with the reagent acting as a dipolarophile to give a />OT-fused tricyclic intermediate containing a hypervalent sulfur atom 139. This intermediate can undergo isothiocyanate elimination to furnish 140. It is interesting to note that the sulfur atom of the thione moiety in the product is derived from carbon disulfide. 

Most of the cyclizations of the five-membered ring relating this type of fused [l,2,4]triazines concern the synthesis of [l,3,4]thiadiazolo[2,3-c][l,2,4]triazines. These synthetic approaches are similar in respect to the starting compound, which is a substituted 4-amino-3-mercapto[l,2,4]triazine-5(477)one 218 in each case. The ring-closure reactions can be classified into four related categories according to the reagent used aldehyde, isothiocyanate, carbon disulfide, or an acid. 

The same starting compound 270 was also subjected to ring closure by using other reagents <2003PS1143> reaction of 270 with acetic anhydride afforded the methyl-substituted 272, whereas reaction with carbon disulfide yielded the 3-mercapto derivative 273. 

The solvents and coupling reagents were reagent grade materials. The tricaprylmethylammonium chloride (Adogen 464) was not purified further. Intrinsic viscosities were measured in chloroform at 25. Infrared spectra for hydroxyl analysis were measured on 2.5% solutions in carbon disulfide (vs. carbon disulfide2.in a cell with a 1.00 cm path length. The absorbance at 3610 cm was subtracted from a similar spectrum of 2 which had been quantitatively acetylated. 

Special attempts were made to identify carbonyl sulfide as a metabolite of dichlofluanld because it would help us understand the metabolic pathway. In a previous investigation into the metabolism of captan, CS was found as a metabolite (4), while in a latter study, COS was reported ( 17). Viles reagent (18) often used by many investigators for this purpose, proved to be unsuitable because of the possible presence of carbon disulfide. Both COS and CS2 give colored copper chelates that can not be quantitatively separated by tic. Furthermore, analysis of the mixtu-... 

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