Ethyl decomposition

The additives for improving the cetane number, called pro-cetane, are particularly unstable oxidants, the decomposition of which generates free radicals and favors auto-ignition. Two families of organic compounds have been tested the peroxides and the nitrates. The latter are practically the only ones being used, because of a better compromise between cost-effectiveness and ease of utilization. The most common are the alkyl nitrates, more specifically the 2-ethyl-hexyl nitrate. Figure 5.12 gives an example of the... 

Hase W L and Buckowski D G 1982 Dynamics of ethyl radical decomposition. II. Applicability of classical mechanics to large-molecule unimolecular reaction dynamics J. Comp. Chem. 3 335-43... 

Dissolve 13 g. of sodium in 30 ml. of absolute ethanol in a 250 ml. flask carrying a reflux condenser, then add 10 g. (9 5 ml.) of redistilled ethyl malonate, and place the flask on a boiling water-bath. Without delay, add a solution of 5 3 g. of thiourea in a minimum of boiling absolute ethanol (about 100 ml.). The sodium salt of thiobarbituric acid rapidly begins to separate. Fit the water-condenser with a calcium chloride guard-tube (Fig. 61, p. 105), and boil the mixture on the water-bath for 1 hour. Cool the mixture, filter off the sodium salt at the pump and wash it with a small quantity of cold acetone. Dissolve the salt in warm water and liberate the acid by the addition of 30 ml. of concentrated hydrochloric acid diluted with 30 ml. of water. Cool the mixture, filter off the thiobarbituric acid, and recrystallise it from hot water. Colourless crystals, m.p. 245 with decomposition (immersed at 230°). Yield, 3 5 -4 0 g. 

Ethyl acetoacetate may be prepared by the action of sodium upon dry ethyl acetate and decomposition of the resulting sodio compound with dilute acetic acid. Most samples of ethyl acetate contain some ethyl alcohol and it is usually assumed that sodium ethoxidc is the condensing agent ... 

Ethyl acetoacetate decomposes slightly (with the formation of dehydracetio acid C,H,0,) when distilled at atmospheric pressure. The extent of decomposition is reduced if the distillation is conducted rapidly. The b.p, is 180°/760 mm. and a 6° fraction should be collected. Normal pressure distillation is not recommended if a pure product is desired. 

Ben2onitri1e [100-47-0] C H CN, is a colorless Hquid with a characteristic almondlike odor. Its physical properties are Hsted in Table 10. It is miscible with acetone, ben2ene, chloroform, ethyl acetate, ethylene chloride, and other common organic solvents but is immiscible with water at ambient temperatures and soluble to ca 1 wt% at 100°C. It distills at atmospheric pressure without decomposition, but slowly discolors in the presence of light. 

Other acetyl chloride preparations include the reaction of acetic acid and chlorinated ethylenes in the presence of ferric chloride [7705-08-0] (29) a combination of ben2yl chloride [100-44-7] and acetic acid at 85% yield (30) conversion of ethyUdene dichloride, in 91% yield (31) and decomposition of ethyl acetate [141-78-6] by the action of phosgene [75-44-5] producing also ethyl chloride [75-00-3] (32). The expense of raw material and capital cost of plant probably make this last route prohibitive. Chlorination of acetic acid to monochloroacetic acid [79-11-8] also generates acetyl chloride as a by-product (33). Because acetyl chloride is cosdy to recover, it is usually recycled to be converted into monochloroacetic acid. A salvage method in which the mixture of HCl and acetyl chloride is scmbbed with H2SO4 to form acetyl sulfate has been patented (33). 

Dibromoacetic acid [631-64-1] (Br2CHCOOH), mol wt 217.8, C2H2Br202, mp 48°C, bp 232—234°C (decomposition), is soluble in water and ethyl alcohol. It is prepared by adding bromine to boiling acetic acid, or by oxidi2ing tribromoethene [598-16-3] with peracetic acid. 

Tribromoacetic acid [75-96-7] (Br CCOOH), mol wt 296.74, C2HBr302, mp 135°C bp 245°C (decomposition), is soluble in water, ethyl alcohol, and diethyl ether. This acid is relatively unstable to hydrolytic conditions and can be decomposed to bromoform in boiling water. Tribromoacetic acid can be prepared by the oxidation of bromal [115-17-3] or perbromoethene [79-28-7] with fuming nitric acid and by treating an aqueous solution of malonic acid with bromine. 

Triiodoacetic acid [594-68-3] (I CCOOH), mol wt 437.74, C2HO2I3, mp 150°C (decomposition), is soluble in water, ethyl alcohol, and ethyl ether. It has been prepared by heating iodic acid and malonic acid in boiling water (63). Solutions of triiodoacetic acid are unstable as evidenced by the formation of iodine. Triiodoacetic acid decomposes when heated above room temperature to give iodine, iodoform, and carbon dioxide. The sodium and lead salts have been prepared. 

Beryllium Hydride. BeryUium hydride [13597-97-2] is an amorphous, colorless, highly toxic polymeric soHd (H = 18.3%) that is stable to water but hydroly2ed by acid (8). It is insoluble in organic solvents but reacts with tertiary amines at 160°C to form stable adducts, eg, (R3N-BeH2 )2 (9). It is prepared by continuous thermal decomposition of a di-/-butylberylhum-ethyl ether complex in a boiling hydrocarbon (10). 

Low boiling isocyanates, such as methyl isocyanate [624-83-9] are difficult to prepare via conventional phosgenation due to the fact that the A/-alkyl carbamoyl chlorides are volatile below their decomposition poiat. Interestingly, A/-ethyl carbamoyl chloride decomposes at its boiling poiat whereas the A/-propyl carbamoyl chloride is thermoly2ed cleanly into isocyanate and hydrogen chloride. 

Alkoxyall l Hydroperoxides. These compounds (1, X = OR , R = H) have been prepared by the ozonization of certain unsaturated compounds in alcohol solvents (10,125,126). 2-Methoxy-2-hydroperoxypropane [10027-74 ] (1, X = OR , R" = methyl), has been generated in methanol solution and spectral data obtained (127). A rapid exothermic decomposition upon concentration of this peroxide in a methylene chloride—methanol solution at 0°C has been reported (128). 2-Bromo-l-methoxy-l-methylethylhydroperoxide [98821-14-8]has been distilled (bp 60°C (bath temp.), 0.013 kPa) (129). Two cycHc alkoxyaLkyl hydroperoxides from cyclodecanone have been reported (1, where X = OR R, R = 5-oxo-l, 9-nonanediyl) with mp 94—95°C (R" = methyl) and mp 66—68°C (R" = ethyl) (130). Like other hydroperoxides, alkoxyaLkyl hydroperoxides can be acylated or alkylated (130,131). 

A (4-Hydroxyphenyl)glycine. This derivative (23) forms aggregate spheres or shiny leaflets from water. It turns brown at 200°C, begins to melt at 220°C, and melts completely with decomposition at 245 —247°C. The compound is soluble in alkaU and mineral acid and sparingly soluble in water, glacial acetic acid, ethyl acetate, ethanol, diethyl ether, acetone, chloroform, and benzene. 

Other by-products include acetone, carbonaceous material, and polymers of propylene. Minor contaminants arise from impurities in the feed. Ethylene and butylenes can form traces of ethyl alcohol and 2-butanol. Small amounts of / -propyl alcohol carried through into the refined isopropyl alcohol can originate from cyclopropane [75-19-4] in the propylene feed. Acetone, an oxidation product, also forms from thermal decomposition of the intermediate sulfate esters, eg. 

The heavy metal salts, ia contrast to the alkah metal salts, have lower melting points and are more soluble ia organic solvents, eg, methylene chloride, chloroform, tetrahydrofiiran, and benzene. They are slightly soluble ia water, alcohol, ahphatic hydrocarbons, and ethyl ether (18). Their thermal decompositions have been extensively studied by dta and tga (thermal gravimetric analysis) methods. They decompose to the metal sulfides and gaseous products, which are primarily carbonyl sulfide and carbon disulfide ia varying ratios. In some cases, the dialkyl xanthate forms. Solvent extraction studies of a large number of elements as their xanthate salts have been reported (19). 

Further hydrolysis of the carbon disulfide and the trithiocarbonate produces hydrogen sulfide, etc (33). In another study of the decomposition of sodium ethyl xanthate [140-90-9] in flotation solutions, eleven components of breakdown were studied. The dependence of concentration of those components vs time was examined by solving a set of differential equations (34). 

Because of hydrate formation, the sodium salts tend to be difficult to dry. Excess water over that of hydration is beheved to accelerate the decomposition of the xanthate salts. The effect of heat on the dryiag of sodium ethyl xanthate at 50°C has been studied (84) ... 

Although in the dry state carbon tetrachloride may be stored indefinitely in contact with some metal surfaces, its decomposition upon contact with water or on heating in air makes it desirable, if not always necessary, to add a smaH quantity of stabHizer to the commercial product. A number of compounds have been claimed to be effective stabHizers for carbon tetrachloride, eg, alkyl cyanamides such as diethyl cyanamide (39), 0.34—1% diphenylamine (40), ethyl acetate to protect copper (41), up to 1% ethyl cyanide (42), fatty acid derivatives to protect aluminum (43), hexamethylenetetramine (44), resins and amines (45), thiocarbamide (46), and a ureide, ie, guanidine (47). 

Ethyl chloride can be dehydrochlorinated to ethylene using alcohoHc potash. Condensation of alcohol with ethyl chloride in this reaction also produces some diethyl ether. Heating to 625°C and subsequent contact with calcium oxide and water at 400—450°C gives ethyl alcohol as the chief product of decomposition. Ethyl chloride yields butane, ethylene, water, and a soHd of unknown composition when heated with metallic magnesium for about six hours in a sealed tube. Ethyl chloride forms regular crystals of a hydrate with water at 0°C (5). Dry ethyl chloride can be used in contact with most common metals in the absence of air up to 200°C. Its oxidation and hydrolysis are slow at ordinary temperatures. Ethyl chloride yields ethyl alcohol, acetaldehyde, and some ethylene in the presence of steam with various catalysts, eg, titanium dioxide and barium chloride. 

Chloro-l,2-propanediol [96-24-2] HOCH2CHOHCH2CI, a liquid with = 1.4831 (6), boils at 213°C and 101.3 kPa (1 atm) with decomposition. It can be distilled at 114—120°C at 1.87 kPa (14 mm Hg). Synonyms for this compound include 3-chloro-l,2-dihydroxypropane, glycerol monochlorohydrin, a-chlorohydrin, and 3-chloropropylene glycol. It is miscible in water, ethanol, ethyl ether, and acetone [67-64-1] (8) and is soluble in hot... 

Cobalt salts are used as activators for catalysts, fuel cells (qv), and batteries. Thermal decomposition of cobalt oxalate is used in the production of cobalt powder. Cobalt compounds have been used as selective absorbers for oxygen, in electrostatographic toners, as fluoridating agents, and in molecular sieves. Cobalt ethyUiexanoate and cobalt naphthenate are used as accelerators with methyl ethyl ketone peroxide for the room temperature cure of polyester resins. 

Acryhc elastomers are normally stable and not reactive with water. The material must be preheated before ignition can occur, and fire conditions offer no hazard beyond that of ordinary combustible material (56). Above 300°C these elastomers may pyrolize to release ethyl acrylate and other alkyl acrylates. Otherwise, thermal decomposition or combustion may produce carbon monoxide, carbon dioxide, and hydrogen chloride, and/or other chloiinated compounds if chlorine containing monomers are present ia the polymer. 

Concentration Effects. The reactivity of ethyl alcohol—water mixtures has been correlated with three distinct alcohol concentration ranges (35,36). For example, the chromium trioxide oxidation of ethyl alcohol (37), the catalytic decomposition of hydrogen peroxide (38), and the sensitivities of coUoidal particles to coagulation (39) are characteristic for ethyl alcohol concentrations of 25—30%, 40—60%, and above 60% alcohol, respectively. The effect of various catalysts also differs for different alcohol concentrations (35). 

Pyridinium iodide, l-ethyl-4-methoxycarbonyl-UV spectrum, 2, 127 Pyridinium iodide, 1-methyl-decomposition, 2, 300 Pyridinium iodide, 6-pterinylmethyl-synthesis, 3, 312... 

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