Isopropanol as a solvent

The reaction proceeds by a chain mechanism involving various radical intermediates. Ferric tetraarylporphyrins act as effective light-absorbing catalysts. Using the complex Fe(TDClP)Cl and isopropanol as a solvent, a turnover number, TN, as high as 130000 was achieved. 

Used for the precolumn preparation of fluorescent derivatives of aldehydes, using isopropanol as a solvent in the presence of ammonium acetate Reference 17... 

In pharmaceutical applications the choice of polymorphic modification for formulation depends very much on the robustness of the crystallization process as well as the properties and characteristics of the preferred modification. Hence, considerable effort is expended in gaining control over the polymorphic form obtained under various conditions. As noted above, up to four polymorphic modifications and three monohydrates have been reported for cimetidine (SmithKline Beecham s Tagamet ) (Bavin et flZ.1979 Prodic-Kojic et al. 1979 Shibata etal. 1983 Hegedus and Gorog 1985). In experiments to selectively crystallize the A form in preference to the more stable B congener it was found that with isopropanol as a solvent, A crystallizes exclusively at high supersaturation, in the presence or absence of seeds (Sudo et al. 1991). 

This reaction has the important advantage of not involving hydrogen gas but on the downside the reaction is reversible in some cases, leading to incomplete conversions and racemisation of 39. This problem is minimised by performing the reaction in isopropanol as a solvent. There are few results with P-stereo-genic ligands, listed in Table 7.12. 

Because of its balance between alcohol, water, and hydrocarbon-like characteristics, isopropanol is an excellent, low-cost solvent free from government regulations and taxes that apply to ethanol. The lower toxicity of isopropanol favors its use over methanol. Consequently, isopropanol is used as a solvent in many consumer products and industrial products. It is used widely as a solvent for cosmetics, and many aerosol products contain isopropanol as a solvent. Because it is a good solvent for a variety of oils, gums, waxes, resins, and alkaloids, isopropanol is used for preparing cements, primers, varnishes, paints, and printing inks (Logsdon and Loke 1996). 

Three major non-polymer propylene derivatives are isopropanol, acetone, and acrylic acid. Isopropanol (isopropyl alcohol) is used mainly as a solvent. It has been made from propylene by reaction with sulfuric acid and water for at least the last 75 years, making its manufacture the oldest, still-running commercial organic chemical process. It is used in household rubbing alcohol because, unlike ethanol, it is unfit for human consumption even in small amounts. About 25 % of the isopropanol produced is used for making acetone, in competition with a route based on isopropylbenzene. 

Isopropyl alcohol org chem (CH3)2CH0H A colorless liquid that boils at 82.4°Q soluble in water, ether, and ethanol used in manufacturing of acetone and its derivatives, of glycerol, and as a solvent. Also known as isopropanol 2-propanol sec-propyl alcohol. T-s3 pro-p3l al-k3,h6l ... 

Isopropanol is manufactured in the United States by the indirect hydration of propylene in processes which may involve the use of concentrated or dilute sulfuric acid, whereas, in European countries and Japan, a direct hydration process is used in which propylene reacts with water in the presence of a catalyst. It is used mainly for the production of acetone, but also as a solvent and in the manufacture of other chemicals and in pharmaceutical and cosmetic formulations (lARC, 1977). 

Exposure to isopropanol may occur in its production, in the production of acetone and during its use as a solvent. 

The high pressure, liquid-phase hydrogenation of 3-methyl crotonaldehyde was carried out in a well-stirred batch autoclave under 4 MPa Ha (Air Liquide, 99.995% purity) pressure using 0.1 mol of 3-methyl crotonaldehyde (UAL) (Merck) and 0.6 g catalyst. Isopropanol (37.5 cc) was used as a solvent. The catalyst was activated by stirring under 4 MPa Ha pressure at 373K for two hours prior to introduction of the unsaturated aldehyde UAL reactant at the same temperature. The reaction products were monitored by repetitive sampling and gas chromatographic analysis. Since this was a batch reaction, data are reported as selectivity vs. conversion. Time of reaction to reach about 30% conversion was close to 60 minutes for Ru/NaY and 150 minutes for Ru/KY. 

In this method the sample is reacted with a measured excess of aq KOH, using isopropanol as a mutual solvent, if required (but not for EtAcet). The amt of KOH consumed, which is detd by titrating the excess with std mineral acid, is a measure of the ester originally present. Since this detn is based on acidimetric... 

Isopropanol is used as a solvent in numerous industrial and commercial products including synthetic resins, coatings, lacquers, and paint removers. It is also used in drug and cosmetic formulations, including many toiletries, perfumes, and colognes. It is also found in consumer products such as windshield cleaning fluids and glass cleaners. Because of its... 

Phase solubility analysis is carried out using isopropanol as the solvent. A typical example is shown in Figure 4 which also lists the conditions under which the equilibration took place . However, the inherent instability of acidic solutions of chlordiazepoxide such as the hydrochlorides may result in some decomposition during phase analysis. 

About two-thirds of the isopropanol produced is used as an intermediate to form other chemicals, mostly for acetone production. The remainder is used as a solvent in paints and coatings and other chemical processes. 

Preparation of Extracts. Leffler (L2) and others have previously used isopropanol as a lipid solvent for determining cholesterol. Connerty et al. (C6) and Lofland (L4) also showed that triglycerides and phospholipids are extracted quantitatively. Under our extraction conditions, complete recovery of these lipid fractions is obtained at a serum-to-solvent ratio of 1 10 through 1 25. We routinely use 1 20 dilution (0.5 ml of sera+ 9.5 ml of isopropanol). We find that the addition of Lloyd s reagent removes bilirubin and other chromogenic material present in serum, as well as approximately 80% of the phospholipids present. 

In deacylation, as the enzyme cleaved the phenylacyl group, phenylacetic acid was formed, which lowered the pH of the reaction medium. Base was added to maintain the starting pH. (Note Use of ammonium hydroxide led to the formation of desilylated byproducts desilylation was eliminated when bicarbonates were used.) This approach was not required in the acylation reaction. At pH above 7.5 the (R)-and (S)-amines are practically insoluble in water. Organic solvents were used to extract the free amines from the aqueous reaction medium at pH 8.0. p-Fluoro-benzoyl, 1-naphthoyl, and phenylacetyl derivatives of the racemic amine were prepared and their behavior on the chiral HPLC column was studied. Based on ease of preparation and HPLC analysis, the 1-naphthoyl derivatives (Fig. 7) were preferred. Reversed phase HPLC analysis on a Vydac-C18 analytical column used a gradient of acetonitrile (0.1% triethylamine) in water (0.05% phosphoric acid) to quantify the total amide in the reaction mixture. Chiral HPLC analysis on (S,S) Whelk-O Chiral column used isopropanol hexane (30 70) as a solvent system to separate and quantify the (R)- and (S)-enantiomers. 

Methanol is a toxic alcohol that is used as a solvent. Ethanol is the alcohol consumed in beer, wine, and distilled liquors. Isopropanol is used as a disinfectant. Ethylene glycol (1,2-ethanediol) is used as antifreeze, and glycerol (1,2,3-propanetriol) is used in cosmetics and pharmaceuticals. 

One hundred pounds per hour of a solution containing 35% isopropanol, 65% water are to be reduced to 2% isopropanol with toluene as a solvent. Equilibrium data at 25 C. are available [Washburn and Beguin, J. Am. Chem. Soc. 62, 579 (1940)]. 

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