Water 1-butanol, 210 Table

The prediction of yAB from this rule is approximate but found to be useful in a large number of systems (such as alkanes water), with some exceptions (such as water butanol) (Table 2.3). For example,... 

Note that control and maintenance of low water contents during esterification progress was a difficult task only for reactions carried out with ferf-butanol (Table 2). Besides affecting reaction yields, high water contents favors the reverse reaction (ester hydrolysis) by decreasing even more the amount of ester formed (1,4). 

The hydroxylation of n-hexane on TS-1, in contrast to the epoxidation of propene, reached its maximum rate in the least polar solvent, t-butanol (Table 18.13). Acetonitrile behaved quite similarly to methanol and water [24, 25, 169]. On the assumption that t-butanol was comparable to i-propanol for the effects on adsorption, a clear relationship between rates and partition coefficients was lacking. Considering that hydroxylation and epoxidation involve different active species and mechanisms, a diverse role of the solvent in the two active species could contribute to the differences, whereas the partition coefficients alone could not... 

In order to improve the resolution efficiency, i. e. to increase the yield of the less-soluble three-component diastereomeric salt without any deterioration in the diastereomeric purity, the effect of water in ethanol was examined for a range of 2-75% (w/w) water contents. Table 5.10 shows that the enantiomeric excess of the amine recovered from the less-soluble diastereomeric salt increased and then decreased with decreasing water content, until finally no crystal was obtained. This result indicates that the presence of water in a solvent is essential for the formation of the less-soluble diastereomeric salt and that the three-component salt could possibly deposit in a larger quantity from a solvent less polar than ethanol. On the basis of this consideration, less polar alcohols were used as solvents in the presence of a small amount of water (Table 5.11). When 2-butanol containing two moles of water was used as a solvent, the highest resolution efficiency was achieved. The diastereomeric salt crystals, obtained in all the systems shown in Table 5.11, contained an equimolar amount of water as a component. These results obviously show that water plays a very important role in the formation of stable diastereomeric salt crystals with satisfactory diastereomeric purity. The recrystaUization of the crude salt once from aqueous 2-butanol gave the diastereomeric three-component salt with diastereomeric purity of more than 95 %. The final product (S)-3-(methylamino)-l-(2-thienyl)propan-l-ol with more than 99.5% ee was obtained upon treatment of the recrystaUized salt with aqueous sodium hydroxide, followed by extraction with 2-butanol and crystallization from toluene [21]. 

Table 3.2. Physical properties of water, butanol, and xylene...

Conditions as 17 but with solvent n-butanol-water Cf. Table 115 [170 a]... 

The (15 4 solvent systems were as follows Sj, S2 5) + 4% (w/v) sodium dodecyl sulfate (. S3, S4, and S7 as with respeci to water) in Table 5 S5, n -butanol-glacial acetic acid-water ... 

Figure 3.10 Liquid-liquid equilibria data for three alcohol-water systems. The immiscibility increases from butanol to pentanol and so does the alcohol-water interfacial tension (see Table 3.2 water-butanol 1.8 mN m water-pentanol 6 mN m ). Reprinted from Kontogeorgis and Folas (2010), with permission from John Wiley Sons...

Acute oral LD q data for nitro alcohols in mice are given in Table 1. Because of their low volatiHty, the nitro alcohols present no vapor inhalation ha2ard. They are nonirritating to the skin and, except for 2-nitro-1-butanol, are nonirritating when introduced as a 1 wt % aqueous solution in the eye of a rabbit. When 0.1 mL of 1 wt % commercial-grade 2-nitro-1-butanol in water is introduced into the eyes of rabbits, severe and permanent corneal scarring results. This anomalous behavior may be caused by the presence of a nitro-olefin impurity in the unpurifted commercial product. 

Like the lower alcohols, amyl alcohols are completely miscible with numerous organic solvents and are excellent solvents for nitrocellulose, resia lacquers, higher esters, and various natural and synthetic gums and resius. However, iu contrast to the lower alcohols, they are only slightly soluble iu water. Only 2-methyl-2-butanol exhibits significant water solubiUty. As associated Hquids, amyl alcohols form a2eotropes with water and//or a variety of organic compounds (Table 3). 

Table 8 summarizes domestic consumption by use for amyl alcohols. About 55% of the total 1-pentanol and 2-methyl-1-butanol production is used for zinc diamyldithiophosphate lubrication oil additives (150) as important corrosion inhibitors and antiwear additives. Amyl xanthate salts are useful as frothers in the flotation of metal ores because of their low water solubiUty and miscibility with phenoHcs and natural oils. Potassium amyl xanthate, a collector in flotation of copper, lead, and zinc ores, is no longer produced in the United States, but imports from Germany and Yugoslavia were 910 —1100 t in 1989 (150). 

Propylene oxide is a colorless, low hoiling (34.2°C) liquid. Table 1 lists general physical properties Table 2 provides equations for temperature variation on some thermodynamic functions. Vapor—liquid equilibrium data for binary mixtures of propylene oxide and other chemicals of commercial importance ate available. References for binary mixtures include 1,2-propanediol (14), water (7,8,15), 1,2-dichloropropane [78-87-5] (16), 2-propanol [67-63-0] (17), 2-methyl-2-pentene [625-27-4] (18), methyl formate [107-31-3] (19), acetaldehyde [75-07-0] (17), methanol [67-56-1] (20), ptopanal [123-38-6] (16), 1-phenylethanol [60-12-8] (21), and / /f-butanol [75-65-0] (22,23). 

Nicotinamide is a colorless, crystalline solid. It is very soluble in water (1 g is soluble in 1 mL of water) and in 95% ethanol (1 g is soluble in 1.5 mL of solvent). The compound is soluble in butanol, amyl alcohol, ethylene glycol, acetone, and chloroform, but is only slightly soluble in ether or benzene. Physical properties are Hsted in Table 1. 

The butanols are all colorless, clear Hquids at room temperature and atmospheric pressure with the exception of /-butyl alcohol which is a low melting soHd (mp 25.82°C) it also has a substantially higher water miscibility than the other three alcohols. Physical constants (1) of the four butyl alcohols are given in Table 1. 

Not all organic compounds that contain —OH groups are soluble in water (Table 10.1). As molar mass increases, the polar —OH group represents an increasingly smaller portion of the molecule. At the same time, the nonpolar hydrocarbon portion becomes larger. As a result, solubility decreases with increasing molar mass. Butanol, CH3CH2CH2CH2 OH, is... 

The diastereoselection of the Diels Alder reaction of methyl acrylate with cyclopentadiene was investigated [74] in microemulsions prepared with isooctane oil, CTAB as surfactant and 1-butanol as cosurfactant, and the results were compared with those found in pure solvents and water (Table 6.12). In emulsions rich in 1-butanol and formamide (entries 1 and 4) the reaction was slow (72 h) and the diastereoselectivity was practically the same as that... 

Surfactants employed for w/o-ME formation, listed in Table 1, are more lipophilic than those employed in aqueous systems, e.g., for micelles or oil-in-water emulsions, having a hydrophilic-lipophilic balance (HLB) value of around 8-11 [4-40]. The most commonly employed surfactant for w/o-ME formation is Aerosol-OT, or AOT [sodium bis(2-ethylhexyl) sulfosuccinate], containing an anionic sulfonate headgroup and two hydrocarbon tails. Common cationic surfactants, such as cetyl trimethyl ammonium bromide (CTAB) and trioctylmethyl ammonium bromide (TOMAC), have also fulfilled this purpose however, cosurfactants (e.g., fatty alcohols, such as 1-butanol or 1-octanol) must be added for a monophasic w/o-ME (Winsor IV) system to occur. Nonionic and mixed ionic-nonionic surfactant systems have received a great deal of attention recently because they are more biocompatible and they promote less inactivation of biomolecules compared to ionic surfactants. Surfactants with two or more hydrophobic tail groups of different lengths frequently form w/o-MEs more readily than one-tailed surfactants without the requirement of cosurfactant, perhaps because of their wedge-shaped molecular structure [17,41]. 

Example 4.6 Mixtures of water and 1-butanol (n-butanol) form two-liquid phases. Vapor-liquid equilibrium and liquid-liquid equilibrium for the water-1-butanol system can be predicted by the NRTL equation. Vapor pressure coefficients in bar with temperature in Kelvin for the Antoine equation are given in Table 4.136. Data for the NRTL equation are given in Table 4.14, for a pressure of 1 atm6. Assume the gas constant R = 8.3145 kJ-kmoL -K-1. 

Table 4.14 Data for water (1) and 1-butanol (2) for the NRTL equation at 1 atm6.

Table 15.16 Physical property data for n-butanol and water.

C. Each Figure shows titration data for compositions inside of the miscibility gap (where the "curve" is linear), as well as enthalpies in a single-phase region. Data from the literature are also shown for comparison with the present results (13-161. Table I shows values of the compositions of the aqueous and amphiphilic phases for n-butanol/water at 30.0 and 55.0 °C and for n-butoxyethanol/water at... 

The separation of synthetic red pigments has been optimized for HPTLC separation. The structures of the pigments are listed in Table 3.1. Separations were carried out on silica HPTLC plates in presaturated chambers. Three initial mobile-phase systems were applied for the optimization A = n-butanol-formic acid (100+1) B = ethyl acetate C = THF-water (9+1). The optimal ratios of mobile phases were 5.0 A, 5.0 B and 9.0 for the prisma model and 5.0 A, 7.2 B and 10.3 C for the simplex model. The parameters of equations describing the linear and nonlinear dependence of the retention on the composition of the mobile phase are compiled in Table 3.2. It was concluded from the results that both the prisma model and the simplex method are suitable for the optimization of the separation of these red pigments. Multivariate regression analysis indicated that the components of the mobile phase interact with each other [79],... 

The partition coefficients of non-ionic monomeric contrast agents in the system water/n-butanol are in the range 0.03-0.15. Dimers are more hydrophilic, e.g. with a P value of 0.005 for iotrolan (Table 2). 

The nickel oxide electrode is generally useful for the oxidation of alkanols in a basic electrolyte (Tables 8.3 and 8.4). Reactions are generally carrried out in an undivided cell at constant current and with a stainless steel cathode. Water-soluble primary alcohols give the carboxylic acid in good yields. Water insoluble alcohols are oxidised to the carboxylic acid as an emulsion. Short chain primary alcohols are effectively oxidised at room temperature whereas around 70 is required for the oxidation of long chain or branched chain primary alcohols. The oxidation of secondary alcohols to ketones is carried out in 50 % tert-butanol as solvent [59], y-Lactones, such as 10, can be oxidised to the ketoacid in aqueous sodium hydroxide [59]. 

Solutions are gently mixed according to Table 2.9 in the indicated order and filled up with ddH20. Start the polymerization by addition of Soln. F and pour the mixture immediately into the gel cassette. When the appropriate height is reached, cover the liquid with water or n-butanol to get a smooth surface. Prepare the stacking gel as short as possible before starting the electrophoresis to avoid a decrease of the pH jump between stacking and separation gel by diffusion. 

The hydrated chloride, bromide and iodide (Table 9) are soluble in ethanol, butanol and other organic solvents, but in many systems traces of water cause oxidation, hydrolysis or failure to complex with weak donor ligands. Water can be avoided by dissolving the metal in THF, ethanol or diethyl ether through which hydrogen chloride is bubbled.24,74 75 It is also possible to dissolve or suspend in organic solvents the anhydrous acetate or the halides CrX2 (Table 9), and dehydration of the hydrated halides with 2,3-dimethoxypropane in ethanol, followed by vacuum removal of the liquid, produces mixed alcoholates suitable for use in water-free conditions.76 Triethyl orthoformate may be used similarly. 

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