Formate salts

Salt Formation. Salt-forming reactions of adipic acid are those typical of carboxylic acids. Alkali metal salts and ammonium salts are water soluble alkaline earth metal salts have limited solubiUty (see Table 5). Salt formation with amines and diamines is discussed in the next section. 

Formic acid is currently produced iadustriaHy by three main processes (/) acidolysis of formate salts, which are ia turn by-products of other processes (2) as a coproduct with acetic acid ia the Hquid-phase oxidation of hydrocarbons or (3) carbonylation of methanol to methyl formate, followed either by direct hydrolysis of the ester or by the iatermediacy of formamide. 

The reaction of formate salts with mineral acids such as sulfuric acid is the oldest iadustrial process for the production of formic acid, and it stiU has importance ia the 1990s. Sodium formate [141-53-7] and calcium formate [544-17-2] are available iadustriaHy from the production of pentaerythritol and other polyhydric alcohols and of disodium dithionite (23). The acidolysis is technically straightforward, but the unavoidable production of sodium sulfate is a clear disadvantage of this route. 

World installed capacity for formic acid is around 330,000 t/yr. Around 60% of the production is based on methyl formate. Of the remainder, about 60% comes from Hquid-phase oxidation and 40% from formate salt-based processes. The largest single producer is BASF, which operates a 100,000 t/yr plant at Ludwigshafen in Germany. The only significant U.S. producer of formic acid is Hoechst-Celanese, which operates a butane oxidation process. 

Reactions of the carboxyl group include salt and acid chloride formation, esterification, pyrolysis, reduction, and amide, nitrile, and amine formation. Salt formation occurs when the carboxyUc acid reacts with an alkaline substance (22)... 

This series of prohibitions restricts how wastes subject to LDR requirements are handled. The most visible aspect of the LDR program is the disposal prohibition, which includes treatment standards, variances, alternative treatment standards (ATSs), and notification requirements. Land disposal means placement in or on the land, except in a corrective action unit, and includes, but is not limited to, placement in a landfill, surface impoundment, waste pile, injection well, land treatment facility, salt dome formation, salt bed formation, underground mine or cave, or placement in a concrete vault, or bunker intended for disposal purposes. The other two components work in tandem with the disposal prohibition to guide the regulated community in proper hazardous waste management. The dilution prohibition ensures that wastes are properly treated, and the storage prohibition ensures that waste will not be stored indefinitely to avoid treatment. 

Formic acid is a widely used hydrogen donor.240 Flowever, since the active species in formic acid is the formate anion, it has been demonstrated that formate salts are superior to formic acid. Ammonium formate is used frequently as a hydrogen donor.241-243... 

Transfer hydrogenolysis of benzyl acetate was studied on Pd/C at room temperature using different formate salts.244 Hydrogen-donating abilities were found to depend on the counterion K+ > NH4 + > Na+ > Li+ > H+. Formate ion is the active species in this reaction. Adsorption of the formate ion on the Pd metal surface leads to dissociative chemisorption resulting in the formation of PdH- and C02. The kinetic isotope effect proves that the dissociative chemisorption of formate is the rate-limiting step. The adsorption and the surface reaction of benzyl acetate occurs very rapidly. 

CAS 4368-28-9 39920-04-2 (Racemic mixture) 629653-73-2 (Acetate salt) 18660-81-6 (Citrate salt) 17522-62-2 (Formate salt) 4664-41-9 (Hydrobromide salt) 4664-40-8 (Picrate salt) 129497-92-3 (Trifluoroacetate salt)... 

The standard ruthenium arene and CATHy catalysts are insoluble in water, but are nevertheless stable in the presence of water. Reactions in the I PA system can be carried out in mixtures of isopropanol and water the net effect is a lower rate due to dilution of the hydrogen donor. The use of formate salts in water, with CATHy or other transfer hydrogenation catalysts dissolved in a second immiscible phase was shown to work well with a number of substrates and in some cases to improved reaction rates [34]. The use of water as reaction solvent will be discussed in more detail in Section 35.5. 

Other salts of formic acid have been used with good results. For example, sodium and preferably potassium formate salts have been used in a water/organic biphasic system [36, 52], or with the water-soluble catalysts discussed above. The aqueous system makes the pH much easier to control minimal COz is generated during the reaction as it is trapped as bicarbonate, and often better reaction rates are observed. The use of hydrazinium monoformate salts as hydrogen donors with heterogeneous catalysts has also been reported [53]. 

Triethylammonium formate-formic acid complex, (HC02NHEtj)2(HC02H)3, is used in a one-pot reductive aldol condensation of Meldrum s acid with aldehydes to produce the alkylated derivative [51]. Although feasible, the process has not been adapted for use with a quaternary ammonium formate salt. 

Some basinal evaporites appear to have been deposited by turbidity currents as shown in Figure 17.10c. In this mode of formation, salts originally deposited in shallow waters are transported into the basin by turbidity currents. These salts fill in the basin. The decline in water depth then promotes in situ precipitation of evaporites. Subsidence would have kept the basin floor below the sill. 

Pentaerythritol, used in the production of alkyds, is produced by a crossed Cannizzaro reaction of the aldol condensation product of formaldehyde and acetaldehyde. The by-product formate salt is a major source of formic acid. 

A significant improvement in the method was developed by Nitecki et al. (68JOC864). In this process, A-l-butyloxycarbonyl derivatives of dipeptide esters are deblocked by formic acid (room temperature, 2 h) and the excess formic acid is distilled off. The formate salt of the dipeptide ester left behind is heated with sec-butanol and toluene for 2-3 h under azeotropic distillation conditions to form the cyclodipeptide. The yields... 

Formic acid and formate salts are also effective reducing agents for 7r-allylpalladium complexes (equation 105).301-303... 

Hydrate Conditions for Gas in Pure Water and Forties Formation (Salt) Water... 

As a result of hydrate formation, salt concentration in the free water phases increased to 8.9 wt% from an initial value of 8.1 wt%. 

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