Ethyl- carbamate

When the addition reactions were performed in the presence of (2-ethyl carbamate, 2-(0-ethylcarbamoylamino)-l-alkyl and 2-((2 -ethylcarbamoylamino)-alkyl phenyl tellurium oxides were formed. The tellurium oxides were once again not isolated but reduced with hydrazine hydrate to the corresponding alkyl phenyl telluriums. ... 

NHjCOOCHj) Ethyl carbamate (urethane) n-Propyl carbamate. n-Butyl carbamnte n-Amyl carbamate t o-Amyl carbamate. N-Methylurethane... 

Urethane [51-79-6] (ethyl carbamate) occurs as a natural by-product in fermented products such as wine, Hquors, yogurt, beer, bread, oHves, cheeses, and soy sauces. Whereas urethane has a known cancer etiology in experimental animals, no such relationship has yet been proven in humans (108,109). Alcohol may act by blocking the metaboHsm of urethane, and thus exert a protective effect in humans consuming alcohoHc beverages (110). 

Second-generation juvenoids incorporate more substantial stmctural departures from neotenin and are more resistant to metaboHc and environmental degradation. Epiphenonane, 2-ethyl-3-[3-ethyl-5-(4-ethylphenoxy)-pent-3-en-yl] 2-methyloxirane (131), has a rat oral LD q of 4000 mg/kg. It and similar juvenoids are used in China and Japan to prolong the last larval instar of the silkworm so that silk production is increased 10—15%. Fenoxycarb, ethyl [2-(4-phenoxyphenoxy)ethyl] carbamate (132) (mp 53°C, vp 0.0078 mPa at 20°C), is soluble in water to 6 mg/L. The rat oral LD q is >16,800 mg/kg. Fenoxycarb has a wide spectmm of activity, interfering with the developmental processes of fleas, cockroaches, and ants. 

Bourbon Distillation. The basic distiUation system for the production of bourbon and other straight whiskeys consists of a beer stiU and a beer heater, thumper, or doubler (Fig. 4). The whiskey stiU consists of between 14 and 21 stripping trays. The upper portion of the stiU is fitted with either a bubble cap section or a section packed with copper rings to enhance the removal of unwanted flavors and ethyl carbamate precursors. The reduction of carbamate precursors requites strict adherence to a cleaning protocol with a 5% caustic solution as often as twice a week. 

Ethyl Carbamate. In November 1985, the Canadian Government indicated that it had detected ethyl carbamate [51-79-6] (urethane), a suspected carcinogen, in some wines and distilled spirits. Since that time, the U.S. distilled spirits industry has mounted a serious effort to monitor and reduce the amount of ethyl carbamate (EC) in its products. In December 1985, the Canadian Government set limits of 150 ppb in distilled spirits and 400 ppb in fmit brandies, cordials, and Hqueurs. The FDA accepted a plan in 1987 from the Distilled Spirits Council of the United States (DISCUS) to reduce ethyl carbamate in whiskey to 125 ppb or less, beginning with all new production in January 1989. 

Ethyl carbamate, C2HyN02, is developed naturally during the fermentation of alcohoHc beverages. It also appears in foods such as bread and yogurt. Since ethyl carbamate is not easily distilled, its formation most likely involves a distillable precursor. The mechanism of ethyl carbamate formation probably involves cyanate produced from the oxidation of cyanide or from urea-based compounds in the beer. Cyanate reacts with alcohol to form ethyl carbamate as follows ... 

There are at least three gc methods employed by the ATF, industry, and the government to detect ethyl carbamate. 

Distillers employ a somewhat unique process to make various products and have tailored approaches to control and reduce ethyl carbamate to their own particular process. Some of the methods used are the use of copper packing in the rectifying section of stills, increased frequency of cleaning stills and other equipment, and using a cool-down period in the cleaning procedure. Increased rectification also reduces ethyl carbamate. Keeping the system clean is critical to minimising ethyl carbamate. 

Methyl Carbamate 5. 9-Fluorenylmethyl Carbamate 8. 2,2,2-Trichloroethyl Carbamate 11. 2-Trimethylsilylethyl Carbamate 16. 1,1-Dimethylpropynyl Carbamate 20. 1-Methyl-1-phenylethyI Carbamate 22. 1-Methyl-l-(4-biphenylyl)ethyl Carbamate 24. 1,1 -Dimethy 1-2-haloethyl Carbamate 26. l,l-Dimethyl-2-cyanoethyl Carbamate 28. r-Butyl Carbamate... 

Ethyl carbamate (urethane) [51-79-6] M 88.1, m 48.0-48.6 . Crystd from benzene. 

A. Ethyl N- p-tolylsulfonylmethyl)carhamate,[Carbamic acid, (4 -methyl-phenylsulfonylmethyl)-, ethyl ester]. A solution of 178 g. (1.0 mole) of sodium p-toluenesulfinate (Note 1) in 1 1. of water is placed in a 3-1., three-necked daak, equipped with a condenser, an efficient mechanical stirrer, and a thermometer. After addition of 100 ml. (108 g.) of a 34—37% solution of formaldehyde ca. 1.2-1.4 moles) (Note 2), 107 g. (1.2 moles) of ethyl carbamate (Note 3), and 250 ml. of formic acid (Note 4), the stirred solution is heated to 70°. Soon after this temperature is reached, the reaction mixture becomes turbid by separation of the... 

Ethyl carbamate (J, T. Baker Chemical Company), melting point reported to be 48-50 (but 46-49° was found) was used without purification. The solid was added to the reaction mixture. 

To a solution of 20.8 g. (0.3 mole) of hydroxylamine hydrochloride and 20.6 g. (0.5 mole) of sodium hydroxide (98%) in 100 ml. of water is added 22.26 g. (0.25 mole) of ethyl carbamate. After 3 days at room temperature the solution is cooled in an ice bath and carefully neutralized with concentrated hydrochloric acid (Note 1). If necessary (Note 2), the solution is filtered and then extracted with ether the aqueous phase is evaporated on a water bath under reduced [iressurc as rapidly as possible at a temperature not aliove 50 60 . 

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