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Metal alkoxide-acetic acid reaction

Zinc phthalocyanine (PcZn) is prepared from phthalonitrile in solvents with a boiling point higher than 200 C, e.g. quinoline277,278 or 1-bromonaphthalene,137 or without solvent in a melt of phthalonitrile.83,116 The zinc compound normally used is zinc(ll) acetate or zinc powder. The reaction of zinc(II) acetate with phthalic acid anhydride, urea and ammonium mo-lybdate(VI) is also successful.262 The metal insertion into a metal-free phthalocyanine is carried out in an alcohol (e.g.. butan-l-ol).127,141,290 This reaction can be catalyzed by an alkali metal alkoxide.112,129... [Pg.735]

From the preceding discussion, it is easily understood that direct polyesterifications between dicarboxylic acids and aliphatic diols (Scheme 2.8, R3 = H) and polymerizations involving aliphatic or aromatic esters, acids, and alcohols (Scheme 2.8, R3 = alkyl group, and Scheme 2.9, R3 = H) are rather slow at room temperature. These reactions must be carried out in the melt at high temperature in the presence of catalysts, usually metal salts, metal oxides, or metal alkoxides. Vacuum is generally applied during the last steps of the reaction in order to eliminate the last traces of reaction by-product (water or low-molar-mass alcohol, diol, or carboxylic acid such as acetic acid) and to shift the reaction toward the... [Pg.61]

Most often in these processes, compounds such as acetic acid, acetylacetone (acac, 2,4-pentanedione), or amine compounds are employed, since these compounds readily react with alkoxides.4M877 A typical reaction involves the formation of new chemical species that (hopefully) possess physical and chemical characteristics that are more attractive in terms of solution stability and film formation behavior. An example reaction between a metal alkoxide and acetic acid is shown below ... [Pg.46]

The generation of dichlorocarbene for addition to olefins has been realized by the use of chloroform and alkali metal alk-oxides4 6 (preferably potassium feri-butoxide), sodium trichloro-acetate,6 butyllithium and bromotrichloromethane,7 and the reaction of an ester of trichloracetic acid with an alkali metal alkoxide.2,8 The latter method, which is here illustrated by the preparation of 2-oxa-7,7-dichloronorcarane, generally gives higher yields of adducts. [Pg.40]

Common modifiers used in the sol-gel process are functional alcohols, acetic acid, and acetylacetone. Alcoholysis reactions are the most documented [LiNb(OEt)6] for instance, was converted to LiNb(0C2H40Me>6 in the presence of 2-methoxyethanol [91]. Assembling ligands, such as 2-methoxyethanol or acetic acid, seem more favorable than -diketones for the stabilization of mixed-metal alkoxides. However, the poorly controlled addition of an additive may sometimes modify the mixed-metal species by extracting, at least partially, one metal as an insoluble product or as a complex. [Pg.47]

The first stage of this reaction includes protonation of the imine nitrogen atom by dialkyl H-phosphonate. The reaction occurs at a low rate, while the addition of the so-formed phosphite anion to the electrophilic methine carbon atom (the second step) is a rapid process. Alkaline metals, alkoxides [52], concentrated hydrochloric, or glacial acetic acid [53] are used as catalysts in this addition process. For the basic catalysis with alkaline metals and alkoxides, the same mechanism as in the case of the addition of dialkyl phosphonates to unsaturated compounds has been suggested [52]. When hydrochloric or glacial acetic add are used as catalysts, their catalytic action involves protonation of the imine nitrogen atom [53]. [Pg.125]

However, the gels in this study must be treated under the temperature at which wood is not thermally degraded. Therefore, in a reaction medium of the metal alkoxide/alcohol (solvent)/acetic acid (catalyst), the moisture-conditioned wood or water-saturated wood is soaked at ambient temperature under reduced pressure or atmospheric pressure. The water present within the wood cells initiates the reaction of the hydrolysis and polycondensation of metal alkoxide. The soaked wood is subsequently treated at a temperature between 50 and 60 C for 24h, and at 105°C for another 24h to prepare wood-inorganic composites (Saka, 1992 Ogjso, 1993). [Pg.1765]

Metal alkoxo-acetates can be formed by the reaction of acetic acid (HOAc) with metal alkoxides [156-158], Whereas the addition of HOAc decreases the gel time of silicon alkoxide systems [159], the reverse effect is observed for Ti(OR)4 and Zr(OR)4 [113,158]. To understand this behavior in acetic acid-modified Ti(OR)4 systems, Livage and coworkers [160] and Sanchez and coworkers [148] have performed careful experiments combining XANES, C NMR, IR, and EXAFS. ... [Pg.35]

Reactions using picoline 1-oxides have been less successful than those using picolines. 2- and 4-Picoline 1-oxides did not react with aromatic aldehydes under various acidic and basic conditions, 199 but poor yields of stilbazole oxides were obtained using piperidine acetate in boiling tolu-ene . Under these conditions, the picolines performed no better than their oxides. 3-Methyl-4-nitropyridine 1-oxide reacted with benzaldehyde in presence of piperidine, circumstances under which 3-methyl-4-nitropyridine did not reacti 3 More successful have been reactions of the oxides catalysed by metal alkoxides or hydroxides (p. 383). [Pg.336]

In brief, the chemical principle of the TFA route mainly developed by Fujihara et al. [5] consists of the reaction of a metal alkoxide or acetate with trifluoroacetic acid in an organic, mainly alcoholic, solvent (Equation (6.1)) ... [Pg.136]

A similar mechanism might operate in the activation of an azolium salt by a transition metal compound forming the metal carbene complex. However, since a basic substituent on the metal (acetate, alkoxide, hydride) usually reacts with the H -proton, the proton is removed from the reaction as the conjugate acid and reductive elimination does not occur. [Pg.29]

Alkyl phenyl sulfones (piCj,27) are nearly as acidic as esters hence they are readily deprotonated by n-BuLi, LDA in THF, or EtMgBr in THF to give a-metalated sulfones. Their reaction with aldehydes gives a mixture of diastereomeric P-phenylsul-fone alkoxide adducts. Reductive elimination of the benzenesulfinate moiety from the adduct to produce the alkene is usually slow. To minimize side reactions, the hydroxyl group is first converted to an acetate, benzoate, mesylate, or /7-toluenesul-fonate and then treated with an excess of sodium amalgam [Na(Hg), prepared by adding small pieces of sodium to mercury] in methanol to furnish the trans-dlk n P... [Pg.385]


See other pages where Metal alkoxide-acetic acid reaction is mentioned: [Pg.383]    [Pg.68]    [Pg.71]    [Pg.241]    [Pg.180]    [Pg.217]    [Pg.383]    [Pg.118]    [Pg.140]    [Pg.99]    [Pg.436]    [Pg.537]    [Pg.996]    [Pg.280]    [Pg.24]    [Pg.37]    [Pg.383]    [Pg.142]    [Pg.308]    [Pg.60]    [Pg.388]    [Pg.243]    [Pg.210]    [Pg.175]    [Pg.142]    [Pg.1115]    [Pg.310]    [Pg.525]    [Pg.104]    [Pg.368]    [Pg.497]    [Pg.294]    [Pg.64]    [Pg.294]    [Pg.909]    [Pg.835]    [Pg.835]   
See also in sourсe #XX -- [ Pg.46 ]




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Acetic acid reaction

Acetic acid, metalation

Alkoxides reaction

Metal acetates

Metal alkoxide

Metal alkoxide reactions

Metal alkoxides

Metal alkoxides reactions

Reactions acid-metal

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