Alkaline earth metal alcoholates

New processes include synthesis of /V-alkylated anilines from olefins and aniline in an inert solvent with at least one catalyst from a range that includes alkali metal alcoholates, alkaline earth metal alcoholates, alkali metal amides and alkaline earth amides36. The uses for /V,/V-dimethylaniline (11) include in the manufacture of polyester resins, sulfur recovery (in copper refining), insecticides and fungicides, dyes, pharmaceuticals, explosives, rubber products, specialty isocyanates and petroleum additives. The /V-ethylaniline (26) is a dye intermediate and rubber additive, and is used for bum control in explosives, while /V,/V-diclhylaniline is used in production of polyester resins, pharmaceuticals, diazo prints (lithographic), and dyes, and as a petroleum additive37. 

Related Terms Alcohol, see Alcohols, p.5 Alkali metal alcoholates, self-heating, corrosive, n.o.s., see Organometallics and Related Compounds, p. 167 Alkaline earth metal alcoholates, n.o.s., see... 

Acrolein dimer, stabilized 2607 26 Alkaline Earth Metal Alcoholates, 3205 37... 

ALKALINE EARTH METAL ALCOHOLATES. n.o.s. 3231 52 SELF-RI-.ACTIVE LIQUID TYPE B. temperature controlled... 

Oxygen Acetaldehyde, acetone, alcohols, alkali metals, alkaline earth metals, Al-Ti alloys, ether, carbon disulflde, halocarbons, hydrocarbons, metal hydrides, 1,3,5-trioxane... 

Difluoroethanol is prepared by the mercuric oxide cataly2ed hydrolysis of 2-bromo-l,l-difluoroethane with carboxyHc acid esters and alkaH metal hydroxides ia water (27). Its chemical reactions are similar to those of most alcohols. It can be oxidi2ed to difluoroacetic acid [381-73-7] (28) it forms alkoxides with alkaH and alkaline-earth metals (29) with alkoxides of other alcohols it forms mixed ethers such as 2,2-difluoroethyl methyl ether [461-57-4], bp 47°C, or 2,2-difluoroethyl ethyl ether [82907-09-3], bp 66°C (29). 2,2-Difluoroethyl difluoromethyl ether [32778-16-8], made from the alcohol and chlorodifluoromethane ia aqueous base, has been iavestigated as an inhalation anesthetic (30,31) as have several ethers made by addition of the alcohol to various fluoroalkenes (32,33). Methacrylate esters of the alcohol are useful as a sheathing material for polymers ia optical appHcations (34). The alcohol has also been reported to be useful as a working fluid ia heat pumps (35). The alcohol is available ia research quantities for ca 6/g (1992). 

Other Additives. To provide and maintain the clarity of clear shampoos, the use of either ethyl or isopropyl alcohol maybe employed. Perfumes are added to make shampoos more pleasing in terms of odor, while dyes are incorporated to give visual aesthetics to the products. Salts of ethylenediaminetetraacetic acid are found to sequester and prevent formation of insoluble alkaline-earth metal salts. 

Alkaline earth metal alkoxides decompose to carbonates, olefins, hydrogen, and methane calcium alkoxides give ketones (65). For aluminum alkoxides, thermal stability decreases as follows primary > secondary > tertiary the respective decomposition temperatures are ca 320°C, 250°C, and 140°C. Decomposition products are ethers, alcohols, and olefins. 

From Metals and Alcohol. Alkali metals, alkaline earth metals, and aluminum react with alcohols to give metal alkoxides (2,3,65) ... 

The speed of the reaction depends both on the metal and on the alcohol, increasing as electropositivity iacreases and decreasiag with length and branching of the chain. Thus sodium reacts strongly with ethanol, but slowly with tertiary butyl alcohol. The reaction with alkaU metals is sometimes carried out ia ether, ben2ene, or xylene. Some processes use the metal amalgam or hydride iastead of the free metal. Alkaline earth metals and aluminum are often covered with an oxide film which hinders the reaction. 

Explosive reactions can occur between oxygen and a wide range of chemicals including organic compounds (such as acetone, acetylene, secondary alcohols, hydrocarbons), alkali and alkaline earth metals, ammonia, biological specimens previously anaesthetized with ether, hydrogen and foam rubber. 

Another marked physical difference between sulphides and sulphoxides (or sulphones) is that sulphoxides (and lower alkyl sulphones) are hygroscopic and dissolve quite readily in water or protic solvents such as alcohols, and even more so lower alkyl or alkyl aryl sulphoxides are almost freely miscible with water. This can be accounted for by the formation of the strong hydrogen bond between the S—O bond in the sulphoxides and water molecules. Moreover, lower alkyl sulphoxides and sulphones such as dimethyl sulphoxide (DMSO) or sulpholene can dissolve a number of metallic salts, especially those of alkali and alkaline earth metals, and hence these compounds have been widely utilized as versatile and convenient solvents in modern organic chemistry26 (Table 3). 

The alcohol sulfate salts of monovalent metals, such as sodium and potassium, crystallize as anhydrous salts from aqueous solutions, whereas salts of bivalent alkaline earth metals form hydrates with 1 mol of water less than that of the equivalent inorganic sulfate [68]. 

Krafft temperatures depend not only on chain length but on the cation. Eth-oxylation of the base alcohol reduces the Krafft temperature due to the higher solubility of the sulfate. Calcium and other earth alkaline metals produce an increase of the Krafft temperature that is significantly reduced by ethoxylation of the alcohol. The decrease is more significant for alkaline earth metals than for alkaline cations as shown in Table 6 [81,82], although it should be noted that, according to other workers, sodium dodecyl sulfate has a Krafft temperature of 16°C. 

Biodiesel is a mixture of methyl esters of fatty acids and is produced from vegetable oils by transesterification with methanol (Fig. 10.1). For every three moles of methyl esters one mole of glycerol is produced as a by-product, which is roughly 10 wt.% of the total product. Transesterification is usually catalyzed with base catalysts but there are also processes with acid catalysts. The base catalysts are the hydroxides and alkoxides of alkaline and alkaline earth metals. The acid catalysts are hydrochloride, sulfuric or sulfonic acid. Some metal-based catalysts can also be exploited, such as titanium alcoholates or oxides of tin, magnesium and zinc. All these catalyst acts as homogeneous catalysts and need to be removed from the product [16, 17]. The advantages of biodiesel as fuel are transportability, heat content (80% of diesel fuel), ready availability and renewability. The... 

Adsorption of a specific probe molecule on a catalyst induces changes in the vibrational spectra of surface groups and the adsorbed molecules used to characterize the nature and strength of the basic sites. The analysis of IR spectra of surface species formed by adsorption of probe molecules (e.g., CO, CO2, SO2, pyrrole, chloroform, acetonitrile, alcohols, thiols, boric acid trimethyl ether, acetylenes, ammonia, and pyridine) was reviewed critically by Lavalley (50), who concluded that there is no universally suitable probe molecule for the characterization of basic sites. This limitation results because most of the probe molecules interact with surface sites to form strongly bound complexes, which can cause irreversible changes of the surface. In this section, we review work with some of the probe molecules that are commonly used for characterizing alkaline earth metal oxides. 

The Guerbet reaction is an important industrial process for increasing the carbon numbers of alcohols. Thus, a primary or secondary alcohol reacts with itself or another alcohol to produce a higher alcohol (Scheme 23). Alkaline earth metal oxides have been used as catalysts for the condensation of alcohols. Ueda et al. (158,159) reported the condensation of methanol with other primary or secondary alcohols having a methyl or methylene group at the )S-position they used MgO, CaO, and ZnO as catalysts. The reactions were performed with gas-phase reactants at 635 K only MgO was found to be both active and selective (>80%). 

Conjugate addition of methanol to a,/l-unsaturated carbonyl compounds forms a new carbon-oxygen bond to yield valuable ethers (Scheme 26). Kabashima et al. (12) reported the conjugate addition of methanol to 3-buten-2-one on alkaline oxides, hydroxides, and carbonates at a temperature of 273 K. The activities of the catalyst follow the order alkaline earth metal oxides > alkaline earth metal hydroxides > alkaline earth metal carbonates. All alkaline earth metal oxides exhibited high catalytic activities and, as in alcohol condensations and nitroaldol reactions, their catalytic activities were not much affected by exposure to CO2 and air. 

By this approach, esters such as di(2-ethylhexyl) adipate and an oligomeric ester of neopentyl glycol have been synthesized recently by alcoholysis of dimethyl adipate ester and the corresponding alcohols, with alkaline earth metal compounds as the catalysts (171) (Scheme 30). These types of esters find application as lubricants, and it is suggested that they can be used as environment-friendly substitutes for petroleum-derived lubricants. The reactions were carried out with isooctane as a... 

According to the Lewis theory, alkaline earth metal hydroxides are weaker bases than their oxides, the order of the strength of the basic sites being Ba(OH)2> SrO(OH)2 > Ca(OH)2 > Mg(OH)2. The hydroxides have been used recently as solid catalysts for organic transformations, such as the conjugate addition of methanol to a, S-unsaturated carbonyl compounds (12), cyanoethylation of alcohols (163,164), and transesterification reactions (166,167,171,172) which are described above. The extensive work of Sinisterra et al. (282) on the number and nature of sites and on the catalytic activity of the most basic alkali metal hydroxide, Ba(OH)2, is emphasized. It was found that commercial barium hydroxide octahydrate can be converted into... 

The establishment of the equilibrium is often accelerated by acidic or basic catalysts, for example, by strong acids (p-toluenesulfonic acid), metal oxides (antimony trioxide), Lewis acids (titanium tetrabutoxide, tin acetates or tin oc-toates), weak acid salts of alkali metals or alkaline earth metals (acetates, benzoates), or by alcoholates. 

Cationic polymerization of alkylene oxides generally produces low molecular weight polymers, although some work [26] seems to indicate that this difficulty can be overcome by the presence of an alcohol (Fig. 1.3). Higher molecular weight polyethylene oxides can be prepared by a coordinated nucleophilic mechanism that employs such catalysts as alkoxides, oxides, carbonates, and carboxylates, or chelates of alkaline earth metals (Fig. 1.4). An aluminum-porphyrin complex is claimed to generate immortal polymers from alkylene oxides that are totally free from termination reaction [27]. 

The crystal structures of alkaline earth metal complexes of several (1 + 1) and (2 + 2) Schiff base macrocycles have been reported. These macrocycles are formed by the metal template-controlled condensation of the required heterocyclic dicarbonyl derivative and a, co functional diamine in alcoholic solution. (1 +1) complexes arise from the condensation reaction of one dicarbonyl with one diamine and (2 + 2) complexes from the condensation of two dicarbonyls with two diamines. 

The simplest method, in practice, for the production of the alkali polysulphides is supplied by the interaction of sulphur and the alkali sulphide in hot aqueous or alcohol solution.2 Liver of sulphur, obtained by fusing sulphur with potassium carbonate,3 is, when freshly prepared, mainly a mixture of potassium polysulphides with potassium thiosulphate. Solutions of the hydroxides of the alkali or alkaline earth metals also dissolve sulphur, yielding solutions of the polysulphides and thiosulphates of the corresponding metals (see p. 87). When a suspension of sulphur in aqueous ammonia is treated with hydrogen sulphide in the absence of air, a red solution is obtained, which on cooling yields yellow crystals of ammonium pentasulphide, (NH4)2S5.4 Bloxam claimed 5 to have separated tetra-, penta-, hepta- and nona-sulphides in this way, whilst Thomas and Riding,6 using alcoholic ammonia, obtained only what they considered to be di-, penta- and hepta-sulphides. Mills and Robinson, however, were unable to obtain evidence of the formation of any polysulphide other than the pentasulphide. 

When arsine is passed over a heated metal, such as the alkali and alkaline earth metals, zinc or tin, the decomposition of the gas is accelerated and the arsenide of the metal is formed. If platinum is used, the removal of arsenic from the gas is complete.3 The action of sodium or potassium on arsine in liquid ammonia yields 4 the dihydrogen arsenide (MHgAs). Heated alkali hydroxides in the solid form quickly decompose the gas, forming arsenites, and at higher temperatures arsenates and arsenides of the metals.5 The aqueous and alcoholic solutions have no appreciable action.6 When the gas is passed over heated calcium oxide the amount of decomposition is not more than that due to the action of heat alone. Heated barium oxide, however, is converted into a dark brown mixture of barium arsenite and arsenate, hydrogen being liberated.7 The gas is absorbed by soda-lime.8... 

Adducts of alkali metal salts prepared in anhydrous alcoholic media generally retain very little alcohol of solvation after being dried under vacuum at room temperature (see Table I). The unusual ability of adducts of D-glucitol to retain alcohol is probably due largely to the great ability of D-glucitol itself to retain solvent. Adducts of alkaline-earth metal salts, however, are more strongly solvated by alcohol than adducts of alkali metal salts. For example,21 lactose CaClj 4 MeOH is relatively stable at 60° at atmospheric pressure under vacuum (< 19 mm. of Hg), a molecule releases only two of the four molecules of methanol. From aqueous alcoholic media, adducts of alkaline-earth metal salts tend to crystallize as hydrates. 

In summary, the reaction between an alkali metal alkoxide and a poly-hydroxy compound in hot alcoholic media produces an alcoholate and, possibly, a small proportion of alkoxide adduct however, the conditions governing the ratio of alcoholate to adduct have not yet been well defined. Reactions with alkali metal hydroxides and cyanides produce mixtures (of alcoholate and adduct) that consist mainly of alcoholate. Occurrence of reactions between alkaline-earth metal hydroxides and polyhydroxy compounds in anhydrous alcoholic media has not been reported. 

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