Alcoholic solutions generation

Cyclohexylamine is miscible with water, with which it forms an azeotrope (55.8% H2O) at 96.4°C, making it especially suitable for low pressure steam systems in which it acts as a protective film-former in addition to being a neutralizing amine. Nearly two-thirds of 1989 U.S. production of 5000 —6000 t/yr cyclohexylamine serviced this appHcation (69). Carbon dioxide corrosion is inhibited by deposition of nonwettable film on metal (70). In high pressure systems CHA is chemically more stable than morpholine [110-91-8] (71). A primary amine, CHA does not directiy generate nitrosamine upon nitrite exposure as does morpholine. CHA is used for corrosion inhibitor radiator alcohol solutions, also in paper- and metal-coating industries for moisture and oxidation protection. 

The most widely used reaction of organoboranes is the oxidation to alcohols, and alkaline hydrogen peroxide is the reagent usually employed to effect the oxidation. The mechanism, which is outlined below, involves a series of B to O migrations of the alkyl groups. The R—O—B bonds are hydrolyzed in the alkaline aqueous solution, generating the alcohol. 

To be of maximum synthetic value, the generation of the cationic site that initiates cyclization must involve mild reaction conditions. Formic acid and stannic chloride are effective reagents for cyclization of polyunsaturated allylic alcohols. Acetals generate oxonium ions in acidic solution and can also be used to initiate the cyclization of... 

The formation of hydrated electrons by the photolysis of halide ions in solution may be envisaged in two steps. The first step is the CTTS absorption leading to (X -). The second step is a slow, thermal process releasing the electron in competition with degradation and recapture. In the presence of acid and alcohol, photolysis of halide solutions generates H2 with a yield that increases both with acid and alcohol concentrations (seejortner et al., 1962, 1963, 1964). At 25°, the limiting quantum yields are 0.98 for Cl- at 185 nm, 0.6 and 0.5 for Brat 185 and 229 nm, respectively, and 0.3 and 0.25 for I- at 254 and 229 nm, respectively. Since most of these yields are less than 1, the direct reaction of HsO and (Xaq-) is ruled out. Instead, it is proposed that eh is produced from the... 

Adapalene (Differin) is a third-generation retinoid with comedolytic, kera-tolytic, and antiinflammatory activity, ft is available as 0.1% gel, cream, alcoholic solution, and pledgets. A 0.3% gel formulation is also available. 

Since the direct oxidation failed, Wieland used Nef s methods to synthesize oxy-isuretin (formoxyamidoxime), which is generated in situ when formamidoxime, HC(=N0H)NH2, is gently heated with hydroxylamine hydrochloride in methanol (Scheme 10). Oxyisuretin is only stable in solution and gives methylnitrosolic acid and formamidoxime (Scheme 11) upon treatment with an alcoholic solution of KOH. 

Aminolevulinic acid (ALA HCl, Levulan Kerastick) is indicated for the treatment of nonhyperkeratotic actinic keratosis of the face and scalp. It has two components, an alcohol solution vehicle and ALA HCl as a dry solid. The two are mixed prior to application to the skin. When applied to human skin, ALA is metabolized to protoporphyrin, which accumulates and on exposure to visible light produces a photodynamic reaction that generates reactive oxygen species (ROS).The ROS produce cytotoxic effects that may explain therapeutic efficacy. Local burning and stinging of treated areas of skin due to photosensitization can occur. 

The reduction of polyfunctional nitro compounds, nitroaryl as well as nitroalkyl compounds, to the corresponding amines in basic aqueous alcoholic solutions on Raney copper (RCu) is more selective if carried out by generating chemisorbed hydrogen by electroreduction of water (ECff method) than by generating it by leaching of the alloy in situ (CCff method) except in the case of o-iodonitrobenzene (2) for which the CCH method is more selective, ffowever, the most selective method in all cases studied is ECH in neutral medium (pff 3-7). 

The reaction patterns of arylcarbenes with solidified alcohol at 77 K are also completely different from those observed in alcohol solution. For example, generation of phenylcarbene (le) in methanol matrices at 77 K results in the formation of alcohol (63) at the expense of benzyl methyl ether (62), which is the exclusive product in the reaction in alcoholic solution at ambient temperatures (Scheme 9.14). A similar dramatic increase in the CH insertion products is observed in the reaction involving other carbenes with alcohols. ... 

When (trimethylsilyl)carbene (3a) is generated by photolysis of the diazo precursor 19 in an alcohol solution at room temperature, the rearrangement to the silene is so fast that only the addition products of the latter, but not the 0,H insertion product of the carbene, can be isolated (equation 4)34. The same holds true for photolysis in diethylamine38. 

Using a binary sensitizing system (phenanthrene P/DCNB /7-dicyanobenzene) in acetonitrile solution, O-aryl glycosides are transacetalized with alcohols after generation of aromatic radical cations [23], According to kinetic anomeric effects, the a-side attack of nucleophiles to cyclic oxocarbenium ions follows scheme 9. 

It is not clear what the chemical shift of -559 ppm corresponds to. It is close to that of monoanionic vanadate, -560 ppm, but cannot be said to correspond to that chemical shift. Possibly, it corresponds to some species that in the presence of water leads to vanadate but, in aqueous alcoholic solution, also generates an alkoxovanadate. 

In addition to the linear oligomers, cyclic derivatives (V33, V44, V/ ) are also known (see Section 2.2). The latter two are readily formed and are ubiquitous components of aqueous solutions. These compounds are relatively inert to complex-ation reactions that preserve their cyclic structure rather, the equilibria shift towards products of other vanadium stoichiometry. Presumably, one way to generate complexes of these oligomers would be to protonate one or more oxygens so that the reactivity is increased. However, neither protonated V4 nor V5 has been identified in solution, nor has there yet been any indication from studies in alcoholic solution that an alkoxo group can replace an oxo ligand, as might be expected if protonation occurs. 

Under anhydrous conditions, tetranuclear vanadium clusters such as [V404 (0CH2)3CCH3 3(0C2H5)3] can be generated in alcoholic solutions with l,l,l-tris(hydroxymethyl)ethane. The coordination does vary somewhat with the alcohol utilized in the preparation, but all retain the tetranuclear structure. Each vanadium nucleus in the complex has octahedral coordination. The clusters are not stable to hydrolysis and decompose in chloroform solution in the presence of just a few equivalents of water [5],... 

The generation of the free radicals in the photoreduction of anthraquinone by triethylamine was studied in alcoholic solutions by means of FT-EPR (Fourier... 

Sodium hydroxide forms fused solid pieces, granules, rods, or powder. It rapidly absorbs moisture and carbon dioxide from the air. Solutions of sodium hydroxide are very corrosive to animal tissue, and aluminum. It has a melting point of 318 Celsius. Sodium hydroxide is very soluble in water and alcohol. It generates large amounts of heat when dissolving in water, or when mixed with acid. Sodium hydroxide is toxic. Handle sodium hydroxide with care. Sodium hydroxide is a widely available commercial chemical, which is sold under a variety of names such as Lye . Sodium hydroxide is prepared on an industrial scale in a procedure called the chloro-alkali process. In the chloro-alkali process, a sodium chloride solution is electrolysized in a special cell composed of two compartments separated by a porous membrane. Chlorine gas is produced at the positive anode, and sodium hydroxide forms at cathode. 

Propargyl cations may also be generated by heterolytic fission of the C—X bond of allenyl derivatives (178). Early attempts to solvolyse chloride 178 (R = H R = Me) in alcoholic solution, even in the presence of silver nitrate, did not furnish reliable conclusions concerning the possibility of unimolecular solvolysis through the propargyl cation (Pudovik, 1951 Hennion and Maloney, 1951). The apparently slow... 

The conversion of the dithiocarbonates into alkenedithiolates involves base hydrolysis, which is usually effected with sodium alkoxides in alcohol. With the dianion in hand, the synthesis of complexes follows the usual course, as described above. Obviously, oxophilic metal centers, for example, Ti(IV) and Nb(V) (62), are incompatible with the usual alcohol solutions of in situ generated alkenedithiolates. In such cases, the anhydrous salts Na2S2C2R2 are employed in nonhydroxylic solvents, although after complex formation protic solvents are typically employed for cation exchange. 

Some of these cation-radicals have been generated in aqueous or alcoholic solutions by photolytic methods.196,197,209,216 ESR assignments for 1,3-dihydropyrimidiniumyl and 1,2-dihydropyridaziniumyl radicals as well as the isomeric 17 were obtained for aqueous solutions.196 The same three dihydrodiaziniumyl radicals have also been generated by pulse radiolysis, as was 1,4-dihydroquinoxaliniumyl, and spectroscopic, kinetic, and pK data... 

In the sol-gel synthetic method, the gel graduates from inert background material to product. The underlying chemistry remains the same. The silicon-dioxide network is often generated from tetraethyl orthosilicate (Si(OCH2CH3)4), commonly abbreviated TEOS. An alcoholic solution of TEOS undergoes hydrolysis and condensation when added to water to produce Si02( ) and ethanol ... 

Alcoholic solutions of ferric chloride are reduced by light,5 which acts, not as a catalyst, but as a generator of the necessary chemical energy. Ferrous chloride, hydrogen chloride, and formaldehyde are the primary products of the reaction.6... 

---