Cobalt benzoate

Methylene groups in the a positions with respect to carboxylic groups are changed to carbonyl groups thus oi-keto esters are formed. Methyl phenylacetate is oxidized with air in the presence of cobalt benzoate at 110-115 °C to methyl phenylglyoxylate in 86% yield [8], Diethyl malonate is converted by nitrogen sesquioxide (N2O3) into diethyl mesoxalate in 74-76% yield [450],... 

Addition of cobalt benzoate accelerates the rate of oxydecarboxylation however, it also leads to increased tar formation. Use of sodium and potassium... 

Cobaltous benzoate a-Ketocarboxylic from carboxylie acid esters s. lA, 219 (CeHfiOO) Co CH2COOR COCOOR... 

The three chemical reactions in the toluene—benzoic acid process are oxidation of toluene to form benzoic acid, oxidation of benzoic acid to form phenyl benzoate, and hydrolysis of phenyl benzoate to form phenol. A typical process consists of two continuous steps (13,14). In the first step, the oxidation of toluene to benzoic acid is achieved with air and cobalt salt catalyst at a temperature between 121 and 177°C. The reactor is operated at 206 kPa gauge (2.1 kg/cm g uge) and the catalyst concentration is between 0.1 and 0.3%. The reactor effluent is distilled and the purified benzoic acid is collected. The overall yield of this process is beheved to be about 68 mol % of toluene. 

Benzoic Acid. Ben2oic acid is manufactured from toluene by oxidation in the liquid phase using air and a cobalt catalyst. Typical conditions are 308—790 kPa (30—100 psi) and 130—160°C. The cmde product is purified by distillation, crystallization, or both. Yields are generally >90 mol%, and product purity is generally >99%. Kalama Chemical Company, the largest producer, converts about half of its production to phenol, but most producers consider the most economic process for phenol to be peroxidation of cumene. Other uses of benzoic acid are for the manufacture of benzoyl chloride, of plasticizers such as butyl benzoate, and of sodium benzoate for use in preservatives. In Italy, Snia Viscosa uses benzoic acid as raw material for the production of caprolactam, and subsequendy nylon-6, by the sequence shown below. 

The oxidation of cobaltioxalate by ceric and cobaltic ions which results in the quantitative reduction of the Co(III) to Co(II), simultaneously with the oxidation of the oxalate to CO2 (81), is an outstanding example of this type of reaction. Other analogous cases are the oxidations of cobalti-/>-aldehydo-benzoate by Co(III), MnOr and SsC -Ag (40), and of (NH3)6Co(III)(HCOO)+2 by MnOr yielding partially Co(III) (26). The last case is an example of an intermediate which is long lived enough to react with the oxidant if the latter is present in an appreciable excess. 

Methyl benzoate gives88 no carbonyl-containing products over potassium tetrafluoro-cobaltate(III) at 300 °C very low yields of perfluorocyclohexane and perfluorocyclohexene are obtained. 

A somewhat similar catalytic acetoxylation of ethylene to vinyl acetate by 02 has been carried out in acetic acid in the presence of a Pd(OAc)2-pyCo(TPP)N02 system.472 A stoichiometric epoxidation of alkenes such as 1-octene or propene by cobalt-nitro complexes has been shown to occur in the presence of thallium(III) benzoate. Oxygen labeling studies showed that the epoxide oxygen atom comes only from the nitro ligand (equation 197).473... 

Benzene and substituted benzenes are reduced under mild conditions using [Co(C3Hs) P(OMe)3 3] as catalyst. Benzene, anisole and alkylbenzenes are converted to cyclohexanes, while alkyl benzoates give l-alkoxycarbonylcyclohexenes. ° Interesting is the fact that benzene is more easily reduced than cyclohexene because of the special affinity of the benzene ring for cobalt. 

The first phenolic derivative of ferrocene to be reported, di(l-hy-droxy-3-methyl-cyclopentadienyl) iron, was prepared by the reaction between 3-methyl-2-cyclopentanone, sodamide, and ferrous chloride in liquid ammonia. This compound is remarkably unstable, being extremely sensitive to air. It is a yellow substance which sublimes at 130-140° at 0.1 mm pressure, and is readily soluble in methylene dichloride but insoluble in carbon tetrachloride and in n-heptane. In water saturated with nitrogen a yellow solution is produced which rapidly bec( nes blue-green on exposure to air. The compound forms a benzoate (mp 121-123.5°) which is stable in air. An analogous derivative of the dicyclo-pentadienyl cobalt (III) cation has also been obtained (6). 

Decomposition of methanesulphonyl azide in aromatic solvents (methyl benzoate or benzotrifluoride), in the presence of transition metal compounds (e.g. copper(ri) acetylacetonate, manganese(ii) acetylacetonate, di-cobalt octacarbonyl, tri-iron dodecacarbonyl, and iron pentacarbonyl) led to a marked decrease in the aromatic substitution product compared with thermolysis, and, with the iron carbonyls, to an increased yield of methanesulphonamide . In addition, the aromatic substitution products shifted from mainly ortAo-substitution with no additives to mainly w ia-substitution in the presence of the additives mentioned above. 

Reaction with unsaturated compounds (reviews Kharasch,Sosnovsky,andYang reported that, in the presence of a catalytic amount of a copper or cobalt salt, t-butyl perbenzoate reacts with an olefin to give an allylic benzoate with no allylic rearrangement with a terminal olefin the only product isolated was the allylic ester with a terminal double bond. A further example is the reaction with 1-methylene-4-f-butylcyclohexane. However, in contrast to these early reports, Kochi found by o... 

The rate behaviour for the reduction of salicylato and several substituted salicylato derivatives of [(NH3)5Co] was consistent with the intervention of chelated precursor complexes formed from the two cobalt(iii) centres with loss of H, after which internal electron-transfer competes with non-productive dissociation of the precursor. The kinetics of reduction by chromium(ii) of a series of 2-hydroxy-benzenato derivatives of [(NH3)5Co] were compared with those of the 2-amino-benzoate derivatives. A study of the kinetics of dissociation of oxalatobis(phenan-throline)cobalt(iii) into cis-d iaquobis(phenanthroline)cobalt(iii) in aqueous HCl-KCl media found the rate was first order with respect to The photo-redox... 

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