Isopropyl alcohol solutions

Dimenhydrinate. Dimenhydrinate [523-87-5] (Dramamine) (18) is a white crystalline, odorless powder that melts between 102 and 107°C. It is sparingly soluble in water, freely soluble in ethanol and chloroform, and sparingly soluble in diethyl ether. Dimenhydrinate is prepared by combining dimethylaminoethyl ben2hydryl ester with 8-ch1orotheophy11ine and refluxing in an isopropyl alcohol solution. The crystalline precipitate of dimenhydrinate that forms on cooling is collected by filtration, washed with cold ethyl acetate, and dried. 

Medical Usage. Isopropyl alcohol is also used as an antiseptic and disinfectant for home, hospital, and industry (see Disinfectants and antiseptics). It is about twice as effective as ethyl alcohol in these appHcations (153,154). Rubbing alcohol, a popular 70 vol % isopropyl alcohol-in-water mixture, exemplifies the medicinal use of isopropyl alcohol. Other examples include 30 vol % isopropyl alcohol solutions for medicinal liniments, tinctures of green soap, scalp tonics, and tincture of mercurophen. It is contained in pharmaceuticals, eg, local anesthetics, tincture of iodine, and bathing solutions for surgical sutures and dressings. Over 200 uses of isopropyl alcohol have been tabulated (2). 

The TYZOR AA, which is a 75% isopropyl alcohol solution, is unstable in cold storage. The titanate complex precipitates from solution and causes handling difficulties. The addition of small amounts (0.05—0.15 mol water/mol titanate) of water gives a solution, TYZOR AA75, that is stable in cold-temperature storage (95). 

Alcohol holdout tests, which are also used to measure aqueous fluid repeUency, iavolve placing drops of aqueous isopropyl alcohol solutions of concentrations 10, 20,. .. 100 wt % on a fabric surface. The rating for the fabric is based on the most concentrated solution that does not penetrate the fabric ia the specified time frame (3M Water RepeUency Test II, Water/Alcohol Drop Test (41) INDA Standard Test 80.6). 

The silica forms of MCM-41, MCM-48, KIT-1, HMS, and SBA-1 were prepared by hydrothermal synthesis following the methods reported in the literature [1,2,3,4,7]. The calcined mesoporous materials were slurried in absolute isopropyl alcohol solution containing TIPOT (10wt%) with magnetic stirring at room temperature for 3h. The solid products obtained were then washed with absolute isopropyl alcohol, dried and calcined in air at 823K... 

A diamagnetic rose complex formulated as the iridium(II) species IrCl PCy, i Ir-Cl) 317 cm-1, prepared from aqueous isopropyl alcohol solutions containing IrCle3- and PCy3 (4), must be the hydride complex, 3. 

Irradiation (A, > 280 nm) of a hexane/isopropyl alcohol solution of the disilene precursor ( )-14 (Scheme 8) in a quartz tube at room temperature produced threo-1-isopropoxy-1,2-dimethyl-1,2-diphenyldisilane 37a, which is the product of syn addition of isopropyl alcohol to ( )-16 together with a small amount of the erythro-isomer 38a (37a/38a => 99/1, 62% yield). High syw-addition diastereoselectivity was also found... 

Colorless liquid odor of hyacinths bp, 121 128°C.1 Isopropyl alcohol solution (67% by weight) has strong odor.2... 

To an isopropyl alcohol solution of the above free base of the title compound is added in equal molar amount of 37% (cone.) hydrochloric acid. A salt is... 

The reduction of aldehydes and ketones is carried out very easily. The carbonyl compound and aluminum isopropoxide, prepared from aluminum and isopropyl alcohol, are heated in boiling isopropyl alcohol solution with provision for slow distillation until no more acetone is formed. The general equation may be represented as follows. 

Sabina ketone (XXIV)26 and the esters of chelidonic acid (XXV)6 are reported not to be reduced by aluminum isopropoxide in boiling isopropyl alcohol solution. Apparently no attempts have been made to... 

The reagent also is conveniently kept and used as an isopropyl alcohol solution. The molten alkoxide after distillation is weighed and dissolved in sufficient dry isopropyl alcohol to give a 1M solution. This may be kept yrithout deterioration in a glass-stoppered bottle sealed with paraffin. On standing the solution deposits large crystals of the alkoxide, but these redissolve slowly when the mixture is warmed to 60-70°,... 

Unless otherwise stated, the reduction was carried out with aluminum isopropoxide in boding isopropyl alcohol solution. C refers to clarified but undistilled aluminum isopropoxide) D, to distilled reagent and U, to an untreated solution of the aikoxide (see p. 199)... 

What compounds were left behind in the isopropyl alcohol solution after spooling the DNA ... 

Optical methods have found a wide usage for quantitative determination of medical drugs, like tinidazole [1134,1454], metronidazole [1455-1458], In particular, a spectrophotometric method for the estimation of metronidazole and its benzoate in pure form and in pharmaceutical preparations has been used [1458], The method is based on the development of a stable pink color with potassium hydroxide in methanol-isopropyl alcohol solution which can be quantitatively measured at 370 nm. The authors of the work [1457] have stated that the method proposed by them has less error (3 4%) and is less complicated than the used before. The optical properties of organic luminescent microcrystals on the basis of nitrobenzofurazans have been studied [1459],... 

Note 4. Scalbert and Monties (1986) have titrated DMF solutions (20 ml) of lignin in concentrations ranging from 0.25 mg to 1.25 mg ml 1 with 0.05 M TnBAH in isopropyl alcohol solution (Fluka Chemical Corp.). p-Hydroxybenzoic acid (2.5 mg in each lignin solution titrated) was used as an internal standard. 

High-concentration isopropyl alcohol is recovered by the use of per evaporation techniques. Briefly, perevaporation is basically a membrane separation in which the mixture to be separated is vaporized and the vapors are passed over a membrane. The smaller molecule, in this case water, permeates the membrane into a vacuum area where it is condensed and removed. In this manner aqueous isopropyl alcohol solutions can be concentrated above the azeotropic concentration to approximately 99%, if desired (177). Texas A M has also reported that their process works equally well on soybeans. Both alcohol processes are investigations into alternative procedures should petroleum-based solvents no longer be available. Neither process has been put into commercial operation. 

Ketotetrahydrochrysene (XXII) does not undergo reduction with aluminum isopropoxide in boiling isopropyl alcohol but can be reduced to the carbinol in 76% yield by substituting toluene as the solvent. Although no reduction of l-menthen-4-one-3 (XXHI) occurs in isopropyl alcohol solution, substitution of the hi er-boiling isobutyl alcohol results in an 84% yield of stereoisomeric carbinols. 

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