Ethanol additives

The rearrangement discovered by Kolosova et al. probably involves such reactivit (159). This reaction provides a good preparative method for various 5-amino-methylthiazoles (Scheme 43). No mechanism is proposed in the report, and it is not easy to understand how the C-5 enamine-like position competes with the very nucleophilic thiocarbonyl group of the formed A-4-thiazoline-2-thione. An alternative mechanism could start with ethanol addition at C-2. leading to the A-4-thiazoline (90) (Scheme 44). In this intermediate, C-5 nucleophilic reactivity would be favored bv the true enaminic structure. After alkylation on C-5,... 

Mole fraction profiles of C3H3 in a series of fuel-rich propene flames (C/O = 0.5) doped with ethanol, measured by EI-MBMS (left) and VUV-PI-MBMS (right). The inset shows the effect of ethanol addition on the peak mole fraction, normalized to the value in the undoped flame r, mole fraction, h. height. 

Kohse-Hoinghaus, K. et al.. The influence of ethanol addition on premixed fuel-rich propene-oxygen-argon flames, Proc. Combust. Inst., 31,1119, 2007. 

Thiols, Phosphines, Amines, and Silanes. With these ligands, ethanol addition clearly gives a precipitate that can be isolated and readily redispersed in toluene or any other non-polar solvent again. 

As stated previously, the photolysis of cyclobutanone in ethanol solution results in an 8% yield of an acetal, presumably formed from ethanol addition to a carbene intermediate. Alkylation of the a positions of cyclobutanone increases the yield of this rearrangement product,(22)... 

FIGURE 9.15 Separation of poly(styrene-comethyl methacrylate)s on a silica gel column with 5 p.m particles using a solvent gradient including using chloroform with 3.5% ethanol added as the desorption promoting solvent and CO2. Flow rates CO2,0.5 mL/min chloroform with ethanol additive (0.25-2.5 mL/min in 30 min) at 333 K and back pressure 20 MPa. (Reprinted from E. Kawai et al., J. Chromatogr. A, 991 197 (2003). With permission.)... 

Assay and Purification of p-Mannanases. p-Mannanase can be specifically measured in crude enzyme mixtures with a dye-labelled carob galactomannan substrate (6), This substrate has a galactose content high enough (23%) to impart solubility to the substrate, but sufficiently low as not to interfere with the action of p-mannanases on the D-mannan backbone. The soluble dye-labelled substrate is incubated with enzyme preparation under controlled conditions and the reaction is terminated and unreacted dyed polysaccharide precipitated by ethanol addition. 

To a cooled solution of 3,4-dimethoxyphenylethylamine 5.4 g in 20 cc of acetic acid, 4.8 g of bromine in 15 cc of acetic acid is slowly added with stirring. Separation of the product will begin rapidly, and after setting overnight the crystals can be collected and recrystallized from ethanol. Addition of sodium hydroxide to an aqueous solution will precipitate the free base as white plates. Yield 7 g, mp 202-204°. 

TABLE 3-8. Effect of Ethanol Addition on Gasoline Properties... 

When you combined R2C=0H+ with ethanol you formed an adduct (8b) which is the product of ethanol addition to a ketone. The steps you drew are therefore part of the acid catalysed addition of ethanol to a ketone. Draw out the whole of this reaction. 

Brazil s Alcohol Program. In Brazil, the enactment of legislation in 1931 made ethanol addition to gasoline compulsory at a level of 5% (86). Excess molasses and sugar were converted to alcohol in distilleries attached to sugar mills as a means to stabilize sugar prices. Production of fuel ethanol in the 1990s is mosdy from biomass. 

Phenyltrimethyldisilene (15) and ( )- and (Z)-l,2-dimethyl-l,2-diphenyldisilene (16) were also generated (equation 4) by the photolysis of precursors 13, ( )-14 and (Z)-14, respectively28. Absorption maxima of 15, ( )-16 and (Z)-16 were observed at 386, 417 and 423 nm, respectively. These absorption bands are also observed in an organic glass (3-MP, EPA), the ethanol addition products being detected after annealing of the EPA matrix, similar to the case of 11. 

Fink and coworkers showed, however, that the ethanol addition to the sterically highly hindered silacyclobutadiene 296 is a stereospecilic syn addition process163. When 296 is... 

It has been demonstrated that when uracils are iodinated with electrophilic iodine (using chloroamine-T and iodide or Iodo-Gen) in aqueous solution, or NIS in ethanol or chloroform-ethanol, addition products (47 or 48) form initially, eliminating water or ethanol when heated (81RTC267) (Scheme 41). 

Ethanol. Addition of Pt-black, catalyst to ethanol caused ignition.2 Hydrazine. Violently decomposed by Pt-black and H2 evolved may ignite.6 Hydrogen and Air. Explosion occurred when platinized alumina catalyst was purged with air instead of with inert gas after being treated with H2.2... 

A mixture of 3-methylphenylacetonitrile and dry ethanol was cooled in an ice-bath and dry hydrogen chloride was passed. The mixture was allowed to stand at room temperature for 3 days and then treated portionwise, with vigorous shaking and occasional cooling, with a saturated solution of ammonia in dry ethanol. Addition was continued until a smell of ammonia persisted. The mixture was allowed to stand at room temperature for 2 days and then filtered. The fitltrate was treated with a saturated aqueous solution of 1.1 equivalents of sodium p-toluene-sulfonate and diluted with water. The crystalline precipitate was removed and 3-methylphenylacetamidine p-toluenesulphonate (recrystallised from ethanol) was obtained. 

In their stability to dialysis, ethanol addition, heating, and applied pressure, the artificial micelles generally were more similar to native micelles than micelles made with Ca2+ alone (Schmidt and Koops, 1977 Schmidt et al., 1979). 

The (T of ethanol is 22.3 dyn cm-1 and that of pure water is 71.97 dyn cm-1 at 25°C the latter is the highest or ordinary solvents, varying only slightly with temperature. Any ethanol additions to water (o) therefore lower less than that of liquids. 

The ratio of solvent solute is also important as noted by Stuart and Wills (2000b). They noted that as the solvent solute ratio increased from 2 1 to 8 1, alkamide in the extract increased from 37 to 68% for the roots and from 27 to 53% for the aerial parts. As the ratio of solvent solute increases, so does the ethanol level thus enhancing alkamide recovery. In SF extractions, the addition of ethanol (10-12%) as a modifier to the supercritical carbon dioxide enhances the total extract or oleoresin yield but does not significantly influence the alkamide concentrations (Catchpole et al., 2002). Sun et al. (2002) also noted that a 5% ethanol addition did not significantly affect the alkamide recovery. 

Possible toxic reactions of sulfur dioxide are also indicated in Table I. The reaction of bisulfite with aldehydes has a classic position in biochemistry since Neuberg demonstrated in 1918 that the products of fermentation by yeast were altered by the addition of sodium sulfite, which caused the production of equal amounts of the bisulfite addition compound of acetaldehyde and of glycerol. This was concomitant with the blockage of conversion of acetaldehyde to ethanol. Addition compounds can also be formed with quinones and with ,/ -unsaturated compounds. None of these reactions has been adequately assessed as a possible contributor to toxicity. 

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