Carbon disulfide Subject

The reaction of 2-amino-guanidine-1 -acetic acid hydroiodide 331 with carbon disulfide, heating the substrates in DMF at 130-140 °C for 12 h, produces compound 332 in 76% yield. This compound was subjected to cyclization reaction with acetic anhydride to give 6,7-dihydro-5-oxo-imidazo[2,l-f][l,2,4]triazole 102 in 76% yield (Scheme 32) <1998MI1>. 

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. 

CASRN 12427-38-2 molecular formula C4ff6MnN2S4 FW 265.31 Chemical/Physical. When soil containing maneb was subjected to a stream of moist air, carbon disulfide was formed. Carbon disulfide was also formed when maneb was suspended in a O.IM phosphate buffer at pff 7.0 and air was drawn through the system. The rate of carbon disulfide was higher at neutral and acidic solutions but lower under alkaline conditions. When the air was replaced by nitrogen, no carbon disulfide was evolved. Decomposition products in the reaction vessel identified by TLC were ethylene thiourea, ethylene thiuram monosulfide, elemental sulfur, and trace amounts of ethylenediamine (ffylin, 1973). 

Fig (19) Octalin ketal (163) is converted to kete dithioacetal (164) by the cleavage of ketal function and condensation with carbon disulfide and methyl iodide. Subjection of (164) to the action of dimethylsulfonium niethylide and acid hydrolysis leads to the formation of unsaturated lactone (165).lts furan silyl ether derivative is caused to undergo Diets-Atder reaction with methyl acrylate to obtain salicyctic ester (166) which is converted by standard organic reactions toabietane ether (167). It is converted to aiiylic alcohol (168) by epoxidation and elimination. Alcohol (169) obtained from (168) yields orthoamide which undergoes transformation to amide (170). Its conversion to the previously reported intermediate has been achieved by epoxidation, elimination and hydrolysis. 

Thermal Desorption Thermal desorption is an alternative GC inlet system particularly used for VOC analysis. However, the analytes subjected to thermal desorption must be thermally stable to achieve successful analysis. Otherwise, decomposition occurs. This technique is mainly used for determination of volatiles in the air. Such a methodology requires sample collection onto sohd sorbents, then desorption of analytes and GC analysis. Traditionally, activated charcoal was used as a sorbent followed by extraction with carbon disulfide. However, solvent desorption involves re-dilution of the VOCs, thus partially negating the enrichment effect. Therefore, the sampling method is to pump a sample of gas (air) through the sorbent tube containing certain sorbents in order to concentrate the VOC. Afterwards, the sample tube is placed in thermal desorber oven and the analytes are released from the sorbent by application of high temperature and a flow of carrier gas. Additionally, desorbed compounds are refocused in a cold trap and then released into the GC column. Such a two-step thermal desorption process provides a narrow chromatographic band at the head of the column. 

Properties Light-yellow drying oil. D 0.932-0.945, saponification value 191-193, iodine value 187-202, refr index 1.4841. Soluble in alcohol, ether, chloroform, and carbon disulfide. Combustible. Subject to spontaneous heating. 

The experiments I to III demonstrate the pyrophoric nature of the white modi ficaiion of phosphorus (melting point 44.1 °C). The reactivity of P4 is mainly due to the extremely small bond angles in the tetrahedral Ph molecule, which is thus subject to considerable ring strain. White phosphorus is oxidised to P Oic via various intermediate phosphorus oxides. During the oxidation a pale light emission is observed. When white phosphorus is dissolved in carbon disulfide the molecules are dispersed in the solveiu, and the rapid evaporation of CS2 (boiling point 46.2""C) is also accompanied by the oxidation of the phosphorus. Red phosphorus, 111 contrast, does not melt until about 600 C and... 

White phosphorus is known to exist as a P4 molecule wliich is in a tetrahedral configuration containing an atom of phosphorus and an unshared pair of electrons at each apex. Therefore, this allotrope of phosphorus should be subject to easy attack by electrophilic reagents. It is somewhat surprising that only one such reaction has been reported When a solution of wliite phosphorus in carbon disulfide and one molar equivalent of AICI3 at -10 °C was treated witli... 

Gastrointestinal Effects. Gastrointestinal symptoms are commonly reported in workers exposed to carbon disulfide (Rubin and Arieff 1945 Vanhoome et al. 1992b Vigliani 1954). These symptoms are subjective, however, and cannot be identified with a specific exposure level. No animal studies have been done that address effects on the gastrointestinal system. 

The combined effect of carbon disulfide exposure and ethyl alcohol has been examined to determine if carbon disulfide exposure results in the Antabuse syndrome, an intolerance to alcohol. The metabolism of Antabuse, disulfuram, or tetraethylthiuram disulfide (TETD) produces carbon disulfide and diethylamine. The metabolites of Antabuse inhibit the enzymes necessary to metabolize ethyl alcohol (aldehyde dehydrogenase and catalase), which results in the Antabuse syndrome due to a buildup of aldehyde. Symptoms include a sensation of heat, a fall in blood pressure, nausea, and in extreme cases circulatory collapse (Djuric 1971). Research by Freundt et al. (1976) on rats and humans of the combined effects of carbon disulfide exposure and ethanol ingestion indicate that, at low (20 ppm) and medium (400 ppm) levels of carbon disulfide exposure and blood alcohol levels of approximately 0.75%, there is a carbon disulfide inhibition of aldehyde dehydrogenase with an increase in acetaldehyde concentrations in the blood. However, these increased acetaldehyde concentrations were not considered great enough to indicate the Antabuse syndrome. The study authors asserted that the Antabuse syndrome is not likely to occur in subjects who have blood alcohol levels of up to 0.8% and are exposed to 10 ppm carbon disulfide. 

Breath and air collected at sites in and around New York City were measured for carbon disulfide by Phillips (1992). The group tested consisted of four types (male smokers, male nonsmokers, female smokers, and female nonsmokers) with no significant divergence observed among any of the different group types (see Table 5-2). Carbon disulfide was detected in all air and breath samples taken from both indoor air and outdoor locations (see Table 5-3). A general population survey in Italy found low levels of carbon disulfide in the blood of all 208 subjects tested and in the urine of all 1,256 samples taken (Bmgnone et al. 1994). 

Cassitto MG, Bertazzi PA, Camerino D, et al Subjective and objective behavioural alterations in carbon disulphide workers. Med Lav 69 144-150, 1978 Cassitto MG, Camerino D, Imbriani M, et al Carbon disulfide and the central nervous system a 15-year neurobehavioral surveillance of an exposed population. Environ Res 63 252-263, 1993... 

Trace Level Extraction. To provide a challenging sample for evaluation of off-line SEE, activated carbon was spiked at 50 ppm with several polar and higher molecular weight polycyclic aromatic compounds. A one-gram sample was subjected to 16 h of Soxhlet extraction using carbon disulfide and then followed with a second similar extraction using methylene chloride. Another sample was extracted for 1 h with supercritical carbon dioxide at 125 and 400 bar. As shown in Table I, no detectable levels of the compounds were recovered in the combined Soxhlet extracts. However, low levels of the compounds were recovered with supercritical carbon dioxide extraction of the activated carbon. Although only low levels of the... 

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