67-63-0 Isopropanol

Isopropanol is used in certain applications, but owing to its stronger intrinsic odour and slower evaporation characteristics is generally considered technically inferior to ethanol for most applications. The decision to use isopropanol is usually cost driven and related to the tax position for ethanol in that particular country. 

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A fonn of anisotropic etching that is of some importance is that of orientation-dependent etching, where one particular crystal face is etched at a faster rate than another crystal face. A connnonly used orientation-dependent wet etch for silicon surfaces is a mixture of KOH in water and isopropanol. At approximately 350 K, this etchant has an etch rate of 0.6 pm min for the Si(lOO) plane, 0.1 pm min for the Si(l 10) plane and 0.006 pm miiG for the Si(l 11) plane [24]. These different etch rates can be exploited to yield anisotropically etched surfaces. 

Collision-induced dissociation mass spectrum of tire proton-bound dimer of isopropanol [(CH2)2CHOH]2H. The mJz 121 ions were first isolated in the trap, followed by resonant excitation of their trajectories to produce CID. Fragment ions include water loss mJz 103), loss of isopropanol mJz 61) and loss of 42 anui mJz 79). (b) Ion-molecule reactions in an ion trap. In this example the mJz 103 ion was first isolated and then resonantly excited in the trap. Endothennic reaction with water inside the trap produces the proton-bound cluster at mJz 121, while CID produces the fragment with mJz 61. 

Acetone when treated in ethanol with sodium undergoes reduction mainly to isopropanol. By modifying the conditions, however, acetone may be induced to undergo a bimolecular reduction to pinacol. 

Dissolve 1 g. of powdered benzophenone in 6-7 ml. of cold isopropanol with shaking, add 1 drop of glacial acetic acid, and then confine the solution either in a glass receiver having a ground-glass stopper, or in a tube which is sealed... 

When aldehydes or ketones are heated with an excess of isopropanol in the... 

In view of the boiling points of acetone (57°) and isopropanol (82 ), the acetone can be steadily distilled off from the reaction-mixture, and the reduction ultimately becomes virtually complete. 

In the following preparation to illustrate the Meen.vein-Pormdorf-Verley reduc tion, a solution of benzophenone in isopropanol is rapidly reduced in the presence of aluminium isopropoxide to benzhydrol (CaHs)2CO (C Hj)jCH OH. It is clear that the aluminium isopropoxide must take some essential part in this reaction, for benzophenone when dissolved even in cold isopropanol with a trace of acetic acid is reduced to tetraphenylethyleneglycol (p. 150). 

It is advisable in any case before an experiment to place the weighed aluminium isopropoxide overnight in a shallow dish in a vacuum desiccator over sodium hydroxide. The isopropanol should be dried over anhydrous sodium sulphate, and the clear liquid decanted off before use. 

The powdered isopropoxide and the isopropanol must be dried as described above. 

Place in the flask 2 g. of benzophenone, 15 ml. of isopropanol and 2 5 g. of aluminium isopropoxide. This mixture has now to be heated gently under reflux so that the temperature registered by the thermometer in the column does not exceed 80°, i.e., so that only acetone distils. For this purpose, the flask should preferably be heated in an oil-bath direct heating, even over an asbestos sheet, may cause local overheating and decomposition the use of a water-bath on the other hand may make the column undesirably damp. 

The following preparation of triethyl phosphite illustrates the interaction of phosphorus trichloride and ethanol in the presence of dimethylaniline the preparation of di-isopropyl hydrogen phosphite illustrates that of phosphorus trichloride and isopropanol in the absence of a tertiary amine. 

Isopropanol has been used in the above experiment because it gives a greater yield of the phosphite than ethanol gives of diethyl hydrogen phosphite. The latter, b.p. 74 /i4 mm., can be prepared by replacing the isopropanol in the above experiment by 29 ml. (23 g.) of ethanol. 

Place 38 ml. of isopropanol in a two-necked 500 ml. round-bottomed flask fitted with (a) a reflux water-condenser having a calcium chloride tube at the top, and (b) a dropping-funnel. Cool the flask in ice-water and then run 13 5 ml. of phosphorus trichloride in from the dropping-funnel during 15 minutes. Then allow the reaction-mixture to attain room temperature. Now replace the condenser and the... 

Methanol ethanol n-propanol (propan-i-ot) isopropanol (propan-2-ol)i n butanoU glycol, glycerol, benzyl alcohol, cyclohexanol. 

By a similar reaction ethanol gives acetaldehyde (tests, p. 341) and isopropanol gives acetone (tests, p. 345). -Butanol gives butyr dehyde (pleasant characteristic odour and precipitate with 2,4-dinitrophenyl-hydrazine, m.p. 122 ). 

Iodoform Reaction. To 0 5 ml. of ethanol add 3 ml. of 10% KI solution and 10 ml. of NaOCl solution. Warm gently fine yellow crystals of CHI3 separate. Isopropanol gives CHIj in the cold. Pure methanol and the other alcohols in this section go not give the reaction. 

Alkylation of 2-methylaminothiazole (204) with ROH in 85% sulfuric acid gives 2-methylimino-3-alkyl-4-thiazoIine (54). 2-Amino-4-rnethyl-thiazoie alkylated with an excess of isopropanol, however, gives 95% of 2-isopropylamino-4-methyl-5-isopropylthiazole (56). The same result is obtained with cyclohexanol (242). These results and those reported in Sections III.l.C and IV.l.E offer interesting new synthetic possibilities in thiazole chemistry. The reactive species in these alkylations is the conjugate acid of 2-aminothiazole. and the diversity of the products obtained suggests that three nucleophilic centers may be operative in this species. 

Iminothiobutyramide (30), containing four nucleophilic centers (only two of which might react with two electrophilic sites in phenacylbromide), undergoes the Hantzsch reaction preferentially, yielding the enamine (31) in dry dioxane or (4-phenylthiazol-2-yl)acetone (32) in isopropanol. Other enamines are obtainable from the ketone (32) by standard methods (626) (Scheme 15). 

Similarly, 5-thiazole alkanoic acids and their salts are obtained from thioamides and /3-halo -y-keto acids (695). Thus thioarylamides condensed with 3-aroyl-3-bromopropionic acid (88) in isopropanolic solution in the presence of Na COs give first 4-hydroxy-2-aryl-A-2-thiazoline-5-acetic acid intermediates (89), which were dehydrated in toluene with catalytic amounts of p-toluene sulfonic acid to 2,4-diaryl-5-thiazole acetic acid (90) (Scheme 39) (657), with R = H or Me Ar = Ph, o-, m- or p-tolyl, o-, m-, or P-CIC6H4, 0-, m-, or p-MeOC(iH4, P-CF3C6H4, a-thienyl, a-naphthyl (657). 

The reduction of thiazole carboxaldehydes with isopropanol and aluminium isopropoxide gives the corresponding alcohols (37, 107, 108). 

Extracting the aqueous urine sample with a mixture of chloroform and isopropanol separates the quinine and chloride, with the chloride remaining in the urine sample. 

Reversed-phase chromatography is widely used as an analytical tool for protein chromatography, but it is not as commonly found on a process scale for protein purification because the solvents which make up the mobile phase, ie, acetonitrile, isopropanol, methanol, and ethanol, reversibly or irreversibly denature proteins. Hydrophobic interaction chromatography appears to be the least common process chromatography tool, possibly owing to the relatively high costs of the salts used to make up the mobile phases. 

C. Sbeely, Jr., Kinetics of Cataljtk Dehydrogenation of Isopropanol, University Microfilms, Arm Arbor, Michigan, 1953, p. 3. 

Eyrol 51 is a water-soluble Hquid containing about 21% phosphoms. It is made by a multistep process from dimethyl methylphosphonate, phosphoms pentoxide, and ethylene oxide. The end groups are principally primary hydroxyl and the compound can thus be incorporated chemically into aminoplasts, phenoHc resins, and polyurethanes. Eyrol 51, or 58 if diluted with a small amount of isopropanol, is used along with amino resins to produce a flame-retardant resin finish on paper used for automotive air filters, or for backcoating of upholstery fabric to pass the British or California flammabiHty standards. 

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