1,3-Ethylene-2-thiourea

Finelli PF, Morgan TF, Yaar I, et al Ethylene oxide-induced polyneuropathy A clinical and electrophysiologic study Arch Neurol 40 419 21, 1983 

Kuzuhara S Ethylene oxide polyneuropathy Report of 2 cases with biopsy studies of nerve and muscle. Clin Neurol 22 707-713, 1982 

Ohnishi A et ah Ethylene oxide induces central peripheral distal axonal degeneration of the lumbar primary neurones in rats. Br J Ind Med 2-311,-1,19, 1985 

Setzer JV, Brightwell WS, Russo JM, et ah Neurophysiological and neuropathological evaluation of primates exposed to ethylene oxide and propylene oxide. Toxicol Ind Health 12(5) 667-682, 1996 

Hogstedt C, Malmqvist N, Wadman B Leukemia in workers exposed to ethylene oxide.241 1132-1133, 1979 

Submitted by C. F. H. Allen, C. O. Edens, and James VanAllan. Checked by R. L. Shmnxr and Curtis D. Snow. 

In a 2-1. round-bottomed flask are placed 120 g. (1.83 moles) of 92% ethylenediamine (Note 1), 300 ml. of 95% ethanol, and 300 ml. of water. The flask is attached to an efficient reflux condenser, and 121 ml. of carbon disulfide is placed in a separatory funnel attached to the top of the condenser by means of a notched cork. About 15 to 20 ml. of the carbon disulfide is added, and the flask is shaken to mix the contents. A vigorous reaction takes place (Note 2), and it may be necessary to cool the flask. After the reaction has started, a water bath at 60° is placed under the flask and the balance of the carbon disulfide is added at such a rate that the vapors reflux about one-third the way up the condenser. About 2 hours are required for the addition of the carbon disulfide. At this time the bath temperature is raised to about 100°, and the mixture is allowed to reflux for 1 hour. Then 15 ml. of concentrated hydrochloric acid is added, and the mixture is refluxed under a good hood (bath at 100°) for 9 to 10 hours. The mixture is cooled in an ice bath, and the product is filtered by suction on a Buchner funnel and washed with 200-300 ml. of cold acetone (Note 3). A yield of 156-167 g. (83-89%) of white crystals is obtained melting at 197-198° (Note 4). 

If commercial ethylenediamine is used, it should be redistilled. The concentration of the ethylenediamine may be deter- 

Care should be exercised to make certain that the reaction starts, before an additional quantity of carbon disulfide is added. In one experiment in which the carbon disulfide was added all at once, a very violent reaction occurred. 

Since all the likely contaminants are readily volatile, extensive washing is unnecessary. 

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Sulfur Compounds. Ethylene thiourea [96-45-7] a suspected human carcinogen, is prepared by reaction of carbon disulfide [75-15-0] CS[) in aqueous EDA (47). 

If tertiary chlorine atoms are indeed critical to heat resistance, then reactions that consume them should improve polymer stabiUty. This is indeed the case. Post-reaction of polychloroprene with dodecyl mercaptan (111), use of higher levels of ethylene thiourea for curing (112), and inclusion of reactive thiols such as mercaptobenzimidazole in cure systems (113) all improve heat resistance. This latter technique is especially effective in improving the heat resistance of mercaptan modified polychloroprene. 

The organic accelerator most frequendy used is ethylene thiourea. However, concerns about the toxicity of this material have led to its use as a dispersion ia an iaert elastomer, or to replacement by other materials. 

Ethylenethiourea reacts to form monosulftde cross-links (117). A number of alternative curatives have been proposed to avoid use of ethylene thiourea. These iaclude polyhydric phenols (118), hydroxyphenyl and mercapto substituted tria2oles (119), thiolactams (120), thia2o1idinethiones as Vulkacit CRV (121), and alkanethioamides (122). Among these, Vulkacit CRV is the most widely used. An accelerator is ordinarily used ia combination with a retarder to control premature cross-linking. Tetramethylthiuram disulfide [137-26-8] is ordinarily used for this purpose when the accelerator is either ethylenethiourea [96-45-7] or a thia2o1idinethione. 

Ethylene thiourea (2-imidazolidinethione) [96-45-7] M 102.2, m 203-204". Crystd from EtOH or amyl alcohol. 

Ethylene glycol Ethylene glycol dinitrate Ethylene oxide Ethylene thiourea Ethylenimine... 

The Pd-catalysed Heck reaction performed with thiourea as the Ugand exhibit good activities for some catalysts. As for carbene ligands [104], steric hindrance improves catalytic results. Thus, thioureas wearing bulky substituents afford the formation of air- and moisture-stable Pd complexes [105]. For example, the catalyst obtained with 2mol% Pd(dba)2 and Ar,M -dimesitylene-ethylene thiourea (Scheme 24) was still active even after 2 months in an air atmosphere. 

The main method of crosslinking the homopolymer and copolymer is by use of thioureas, and, as the cure reaction requires basic conditions, an acid acceptor is also added. Litharge, red lead, magnesium oxide and dibasic lead phosphite are commonly used acid acceptors, and the most commonly used thiourea is ethylene thiourea, but this has a tendency to promote mould fouling. 

The W types require additional acceleration and ethylene thiourea (ETU), gives the best balance of all properties. However, the use of this accelerator is increasingly being restricted due to fears of its effects on pregnant women, and more recently men. DETU, thiurams and guanidines can also be used. Sulphur is sometimes used to increase the degree of cure in the W types, but this detracts from the ageing performance of the vulcanisate. 

Plant. Major plant metabolites are ethylene thiourea, thiram monosulfide, ethylene thiram disulfide, and sulfur (Hartley and Kidd, 1987). 

Cyclohexanol, Cyclopentane, Cyclopentene, 1,2-Dichloroethane, Diethyl phthalate, 1,4-Dioxane, Ethephon. Ethylamine, Ethylene dibromide, Ethylenimine, p-Propiolactone, Tetraethyl pyrophosphate, TCDD, 1,1,1-Trichloroethane, Trichloroethylene, Vinyl chloride Ethylene chlorohydrin, see Bis(2-chloroethyl) ether Ethylenediamine, see Ethylene thiourea. Maneb Ethylene glycol, see Bis(2-chloroethyl) ether, 1,2-Dichloroethane, Ethylene chlorohydrin. Ethylene dibromide... 

Ethylene thiourea, see Ferbam. Mancozeb. Maneb. Thiram... 

Ethyleneurea see Ethylene thiourea Ethyl formate, see 2-Ethoxyethanol, Ethyl ether s-Ethyl formic acid, see EPTC 5-Ethyl A-formyl-A-propylthiocarbamate, see EPTC 5-Ethyl hexahydro-2-0X0-1 //-azepine-1 -carbothioate, see Molinate... 

ChemicaPPhysical Hwang et al. (2003) studied the chemical oxidation of mancozeb (100 ppm) in aqueous solution using ozone (continuously supplied at a concentration of 3 ppm) and chlorine dioxide (20 ppm). Ozonation of the solution for 60 min yielded several degradation compounds including ethylene thiourea as the major product. Degradation of mancozeb by chlorine dioxide also yielded ethylene thiourea. After 60 min of treatment, mancozeb was still detected suggesting that chlorine dioxide was less effective as an oxidant than ozone. However, the investigators... 

Decomposes in acids releasing carbon disulfide. In oxygenated waters, mancozeb degraded to ethylene thiuram monosulfide, ethylene diisocyanate, ethylene thiourea, ethylenediamine, and sulfur (Worthing and fiance, 1991). 

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). 

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