Isopropyl alcohol effect

Isopropyl alcohol is prepared from petroleum by hydration of propene With a boil mg point of 82°C isopropyl alcohol evaporates quickly from the skin producing a cool mg effect Often containing dissolved oils and fragrances it is the major component of rubbing alcohol Isopropyl alcohol possesses weak antibacterial properties and is used to maintain medical instruments m a sterile condition and to clean the skin before minor surgery... 

Diphenoxylate Hydrochloride. l-(3-Cyano-3,3-diphenylpropyl)-4-phenyl-4-piperidinecarboxyhc acidmonohydrochlorhydrate [3810-80-8] (Lomotil) (13) is a white, odorless, crystalline powder that melts at 220—226°C. It is soluble ia methanol, spariagly soluble ia ethanol and acetone, slightly soluble ia water and isopropyl alcohol, freely soluble ia chloroform, and practically iasoluble ia ether and hexane. The method of preparation for diphenoxylate hydrochloride is available (11). Diphenoxylate hydrochloride [3810-80-8] (13) is an antidiarrheal that acts through an opiate receptor. It has effects both on propulsive motility and intestinal secretion. Commercial forms are mixed with atropiae to discourage abuse. 

Aqueous solutions can be stabilized against viscosity loss by addition of 5—10 wt % anhydrous isopropyl alcohol, ethanol, ethylene glycol, or propylene glycol. The manganous ion (Mn " ) also is an effective stabilizer at concentrations of 10 -10 wt% of the solution. 

Use of isopropyl alcohol in industrial appHcations does not present a health hazard. The alcohol produces anesthetic effects in high vapor concentration. Consequently, the OSHA permissible exposure limit (PEL) and the ACGIH threshold limit value (TLV) have been estabUshed at 400 ppm (0.098 mg/L) for an 8-h exposure (TWA) (138). This level causes a mild irritation of the eyes, nose, and throat (139). However, the TLV level does not produce symptoms of anesthesia (140). The OSHA and ACGIH short-term exposure limits (STELs) are 500 ppm. The odor threshold for isopropyl alcohol ranges from 3 to 200 ppm, which is the minimum concentration having identifiable odor (141). 

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). 

Generally, monochloroacetic acid [79-11-8] (MCA) is added to the reaction slurry containing sufficient excess sodium hydroxide to neutralize the MCA and effect its reaction. The use of esters of MCA has also been reported (52). Common reaction diluents are isopropyl alcohol, /-butyl alcohol, or ethyl alcohol (53,54). Dimethoxyethane has also been reported to be effective (55). The product is isolated and washed with aqueous alcohol or acetone to remove by-product salts. Unpurified cmde grades are generally prepared in the absence of diluents (56—59). 

The substitution of one hydroxyl radical for a hydrogen atom in propane produces propyl alcohol, or propanol, which has several uses. Its molecular formula is C3H7OH. Propyl alcohol has a flash point of 77°F and, like all the alcohols, bums with a pale blue flame. More commonly known is the isomer of propyl alcohol, isopropyl alcohol. Since it is an isomer, it has the same molecular formula as propyl alcohol but a different structural formula. Isopropyl alcohol has a flash point of 53 F. Its ignition temperamre is 850°F, while propyl alcohol s ignition temperature is 700 F, another effect of the different stmcture. Isopropyl alcohol, or 2-propanol (its proper name) is used in the manufacture of many different chemicals, but is best known as rubbing alcohol. 

Undissolved substances were removed by filtration and the filtrate was concentrated on a steam bath to a volume of about 125 ml and cooled to effect crystallization. After 20 hours at room temperature the crystals that had formed were recovered, washed with isopropyl alcohol, and dried, yielding 15.61 grams (46.2%) of crystalline 5-[bis(2-hydroxy-ethyl)amino] uracil having a MP of 157° to 163°C. An analytical sample, obtained by several recrystallizations from isopropyl alcohol, melted at 166° to 168°C. 

Hurley and Testa (Ref 17) exposed nitrobenzene in isopropyl alcohol, degassed and in air, to a mercury lamp at 3660A Products in the absence of air were acetone and phenyl-hydroxylamine (PHA). In air PHA was oxidized to nitro sob enzene which couples with PHA to form azoxybenzene. They hypothesized that the triplet molecule abstracted H-atoms from the solvent no effect was noted with ben zene as solvent. They also worked with nitrobenzene in isopropyl alcohol-water mixts containing HC1 with a mercury lamp at 3660A (Ref 18), and found that the quantum yields depended on pH and isopropyl alcohol content, but were independent of oxygen with acid present. Their conclusion was that the quantum yield consisted of two parts, H abstraction by the triplet, and protonation of the triplet... 

Baltrop and Bunce (Ref 20) employed a variety of radiation wavelengths, nitrocompds and solvents. For wavelengths less than 2900A, aniline was the main product, while above 2900A, bimolecular species such as azobenzene predominated. Since oxygen had little effect on aniline production, expts were performed in the presence of oxygen. For nitrobenzene in isopropyl alcohol, no azoxybenzene was produced as with Hurley and Testa (See above Ref 17). They concluded that the excited state abstracts H-atoms, and suggest that the nitrobenzene triplet is in tt, ti, and that nitrosobenzene is an unobserved intermediate... 

To obtain more information on this point, let us examine the data given in Table 3.6<42-47> for some substituted benzophenones. The data in Table 3.6 indicate that benzophenone derivatives having lowest triplet states of n->TT character undergo very efficient photoreduction in isopropyl alcohol. Those derivatives having a lowest it- -it triplet, on the other hand, are only poorly photoreduced, while those having lowest triplets of the charge-transfer type are the least reactive toward photoreduction. In additon, in some cases photoreduction is more efficient in the nonpolar solvent cyclohexane than in isopropanol. This arises from the solvent effect on the transition energies for -> , ir- , and CT transitions discussed in Chapter 1 (see also Table 3.7). 

All efforts of trying to extract the sodium salt into an organic solvent were unsuccessful, and, thus, a salting out procedure using the common ion effect was used. The product at this stage is in the aqueous phase and addition of 15 g of sodium chloride /100 mL of the reaction mixture, completely precipitates all the coupled sodium salt which is filtered. The filtered crude product is dewatered by washing with isopropyl alcohol or drying under vacuum. The mother liquors... 

The decomposition of methanesulphonyl azide in isopropyl alcohol could be effected by selective irradiation of 2-acetonaphthone instead of benzophenone 21>. Since 2-acetonaphthone triplets are incapable of hydrogen abstraction from isopropyl alcohol 22>, initiation must occur via transfer of excitation energy to the azide. A marked difference was observed from benzophenone sensitization in that the reaction was extremely slow, gave a nitrogen yield of only 68%, and produced a yellow solution 21>. 

Alcoholic KOH. We have reported on the use of isopropyl alcohol as an H-donor solvent in coal conversion, and specifically on the effects of the addition of strong bases such as KOH to the system (la). We found that i-PrOH brought about a conversion of Illinois No. 6 coal very similar to the conversion level obtained by Tetralin under the same conditions. These results are listed in Table IV in text, along with the results of more recent experiments using methanol as the solvent and adding KOH to the system (lb). 

Toluene alkylation with isopropyl alcohol was chosen as the test reaction as we can follow in a detail the effect of zeolite structural parameters on the toluene conversion, selectivity to cymenes, selectivity to para-cymene, and isopropyl/n-propyl ratio. It should be stressed that toluene/isopropyl alcohol molar ratio used in the feed was 9.6, which indicates the theoretical toluene conversion around 10.4 %. As you can see from Fig. 2 conversion of toluene over SSZ-33 after 15 min of T-O-S is 21 %, which is almost two times higher than the theoretical toluene conversion for alkylation reaction. The value of toluene conversion over SSZ-33 is influenced by a high rate of toluene disproportionation. About 50 % of toluene converted is transformed into benzene and xylenes. Toluene conversion over zeolites Beta and SSZ-35 is around 12 %, which is due to a much smaller contribution of toluene disproportionation to the overall toluene conversion. A slight increase in toluene conversion over ZSM-5 zeolite is connected with the fact that desorption and transport of products in toluene alkylation with isopropyl alcohol is the rate controlling step of this reaction [9]... 

Figure 13.6. Effects of stress concentration on breakability. Scanning electron micrographs (top frames) showing breaks of anchored silicon beams etched with (a) plasma, (b) KOH and isopropyl alcohol, and (c) KOH and optical micrographs (bottom frames) of printing results that demonstrate the relative ease of breakability, or the ability for a stamp to separate elements from the anchoring structures in each system. (Reprinted with permission from Ref. 54. Copyright 2007 American Institute of Physics.)...

Surface disinfectants Compounds containing phenolics, chlorhexidine (not effective against bacteria spores), quaternary ammonium salts (additional activity if bis-n-tributyltin oxide present), hypochlorites such as household bleach, alcohols such as 70-95% ethanol and isopropyl (not effective against bacteria spores), potassium peroxymonosulfate, hydrogen peroxide, iodine/iodophores, and triclosan. 

Complexes of N-N bonded dinitrogen dioxide, such as depicted in pathway B of Scheme 5, would appear to be necessary in order to effect the formation of the N-N bond. This has been treated theoretically as a metal promoted reductive coupling of 2 NO to form a hyponitrite complex (79). The Cu Tp112) system was also shown to catalyze NO oxidations of benzyl and isopropyl alcohol to benzaldehyde and acetone (Eq. (37)). Electrospray mass spectrometry indicated that higher... 

This method is very useful for separating amino acids found in food samples. The most effective matrix for separation is an absorbent cellulose-based filter paper. A very effective mobile phase is 70% isopropyl alcohol in water. Although the 20 amino acids are chemically very similar, they may be successfully separated by this method. Amino acids interact with the stationary phase to different extents, thus moving at different speeds. Chemical differences among amino acids that determine migration speed include molecular weight, charge, and polarity. 

TLC has similar applications to paper chromatography. The stationary phase is a coating, such as silica gel, on a glass or plastic plate. Depending on the TLC plate used, components may be separated based on differences in molecular weight, charge, or polarity (see Chapter 11). TLC with a 70% isopropyl alcohol mobile phase and a silica gel plate is an effective substitute for paper chromatography separation of amino acids. Nucleotides may be separated on a special silica gel plate and a 20% ethanol (in water) mobile phase. 

As a result, therefore, acetaldehyde is converted into isopropyl alcohol. Quite generally it may be said that the Grignard reaction consists in the addition to the unsaturated linkage—as H and R—of the hydrocarbon corresponding to the halide used. In effect a synthesising hydrogenation occurs. 

Hunter DM, Timerding BL, Leonard RB, et al. 1992. Effects of isopropyl alcohol, ethanol, and polyethylene glycol/industrial methylated spirits in the treatment of acute phenol bums. Ann Emerg Med 21 1303-1307. 

Similar to Voltaren" Emulgel, oily droplets of an eutectic mixture of lidocaine and prilocaine are dispersed in a hydrogel to provide local anesthesia to the skin for injections and siugical treatment (Emla cream). A further possibility is the dermal administration of a liposome dispersion as a spray (Heparin PUR ratiopharm Spriih-gel "). After administration, water and isopropylic alcohol evaporate partially resulting in an increase of concentration and in a transition from the initial liposome dispersion into a lamellar liquid crystal [32]. The therapeutic effect appears to be influenced favorably by the presence of lecithins rather than by the degree of liposome dispersion. 

Fig. 10.2 Effect of buffer composition on the ESI-FTICR-MS spectrum of a 27mer RNA construct representing the 16S A-site. The spectrum in (a) was acquired from a solution comprised of 33% isopropyl alcohol and 25 mM piperidine/imidazole with an approximate pH of 8.5. The spectrum in (b) was acquired from a solution containing the...

Different stereoselectivities caused by solvent effects are demonstrated in the reduction of dihydroisophorone (3,3,5-trimethylcyclohexanone) with sodium borohydride which gave less stable tranj-3,3,5-trimethylcyclohexanol (with axial hydroxyl) by reduction in anhydrous isopropyl alcohol (55-56%), in anhydrous tert-butyl alcohol (55%), in 65% aqeuous isopropyl alcohol (59.5%), in anhydrous ethanol (67%), and in 71% aqueous methanol (73%) (the balance to 100% being the more stable cis isomer with equatorial hydroxyl) [849]. 

Since sodium borohydride usually does not reduce the nitrile function it may be used for selective reductions of conjugated double bonds in oc,/l-un-saturated nitriles in fair to good yields [7069,1070]. In addition some special reagents were found effective for reducing carbon-carbon double bonds preferentially copper hydride prepared from cuprous bromide and sodium bis(2-methoxyethoxy)aluminum hydride [7766], magnesium in methanol [7767], zinc and zinc chloride in ethanol or isopropyl alcohol [7765], and triethylam-monium formate in dimethyl formamide [317]. Lithium aluminum hydride reduced 1-cyanocyclohexene at —15° to cyclohexanecarboxaldehyde and under normal conditions to aminomethylcyclohexane, both in 60% yields [777]. 

On the basis of acute animal studies, n-propyl alcohol appears to be slightly more toxic than isopropyl alcohol. No chronic effects have been reported in humans, although a human fatality has been ascribed to ingestion. Exposure to 400 ppm for 3-5 minutes will reportedly... 

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