Isopropanol advantages

This indicator possesses the advantage that it may be used under aerobic conditions, in contrast to dyes such as methylene blue (115). Resazurin has also been applied in the study of the dehydrogenation of isopropanol and sorbitol (103), (118). 

Much emphasis has been placed on the selectivity of quaternary ammonium borohydrides in their reduction of aldehydes and ketones [18-20]. Predictably, steric factors are important, as are mesomeric electronic effects in the case of 4-substituted benzaldehydes. However, comparison of the relative merits of the use of tetraethyl-ammonium, or tetra-n-butylammonium borohydride in dichloromethane, and of sodium borohydride in isopropanol, has shown that, in the competitive reduction of benzaldehyde and acetophenone, each system preferentially reduces the aldehyde and that the ratio of benzyl alcohol to 1-phenylethanol is invariably ca. 4 1 [18-20], Thus, the only advantage in the use of the ammonium salts would appear to facilitate the use of non-hydroxylic solvents. In all reductions, the use of the more lipophilic tetra-n-butylammonium salt is to be preferred and the only advantage in using the tetraethylammonium salt is its ready removal from the reaction mixture by dissolution in water. 

Soluble polymer supports, like their insoluble counterparts, offer the advantage of ease of separation. After carrying out a chemical process, the polymer reagent, catalyst, or substrate can be isolated by adding a nonsolvent, for instance, by adding isopropanol for PEG supports. 

The introduction of an inert liquid may have an advantage in equilibrium-controlled reversible reactions. Tf the product is selectively more soluble in the liquid than the reactant, then the composition of the reacting mixture shifts from the equilibrium composition and better conversions are obtained. Zabor et al.58 have shown this to be the case during equilibrium conversion of propylene to isopropanol in the presence of an excess of water and tungsten oxide catalyst. Isopropanol is selectively more soluble in water than propylene, causing reduction of product concentration at the catalyst surface and resulting in better conversions of propylene. 

In the case of a still less reactive halide, or one with a tendency to undergo dehydrohalogenation, it is advantageous to add a reactive halide such as 1-bromo-naphthalene or n-butyl bromide for entrainment. Thus the reaction of 0.05 mole of eyclohexyl chloride and 0.05 mole of 1-bromonaphthalene with 0.33 g. atom of magnesium and isopropanol (0.3 mole) in 50 + 20 ml. of decalin afforded a mixture of 83% of cyclohexane and 10% of cyclohexene (removable with sulfuric acid). By this procedure cyclohexyl fluoride gives cyclohexane (33%) and benzotrifluoride gives toluene (10%). Fluorobenzene is inert. 

Jonkman et al.155 reported the use of a non-polar mobile phase (chloroform - heptane -absolute ethanol - water - acetic acid (600 400 32 1.5 0.8)) in combination with an octadecyl type of stationary phase. The advantage of this method is that chloroform - isopropanol extracts of serum can be injected directly on the column. 

Catalytic hydrogen transfer from a hydrogen donor molecule to an unsaturated substrate sometimes presents advantages over hydrogenation by molecular hydrogen. This type of reaction can be catalyzed by a number of ruthenium or rhodium catalysts. Cycloocta-1,5-diene and hexa-1,5-diene can be selectively reduced to cyclooctene and a mixture of hexenes, respectively, by Rh6(CO)16 via hydrogen transfer from isopropanol.The reaction proceeds at 145°C and a CO pressure of 45 bar. For cycloocta-1,5-diene... 

A preconcentration method that bears some resemblance to SDE consists of isolating the volatile phenols by steam distillation, followed by freeze-drying of the distillate. End analysis was by HPLC with ELD. The method was applied for determination of such phenolic components in foodstuffs and packing materials. Determination of phenolic antioxidants in polyolefins was carried out by dissolving the polymer sample in a hep-tane-isopropanol mixture (1000/5, v/v), at 160-170 °C, in an autoclave. The polymer precipitated on cooling the solution, and the dissolved antioxidant could be determined by LC with UVD. The advantage of the method is the relatively short time of analysis (about 2 h) and its reproducibility (RSD 3-5%) . 

The transformation of the anhydrous sodium warfarin, an amorphous substance, into the solvate, which is crystalline, demonstrates the utilization of technology for some commercial advantages. The amorphous sodium warfarin is crystallized from isopropanol to form a clathrate with a molecular ratio of 2 1. This formation was awarded a patent extension because of the material crystallized out of the solution, resulting in purity improvement. " ... 

A common method for the electrodeposition of Am is from isopropanol solutions containing small quantities of dilute acid stock solutions of Am ions. Aqueous deposition methods have also been employed, but the organic electrolyte medium is more advantageous in that it tends to produce more uniform coatings [151[. Zhi etal. prepared relatively thick targets of Am from a mixture of isopropanol and dilute (0.1 N) nitric acid stock solutions pf [152]. The electrolysis... 

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