Ethane reaction with acetic acid

Analogously, in the presence of silica-supported palladium catalysts, benzene is oxidized under ambient conditions to give phenol, benzoquinone, hydroquinone and catechol [37b]. Palladium chloride, used for the catalyst preparation, is believed to be converted into metallic palladium. The synthesis of phenol from benzene and molecular oxygen via direct activation of a C-H bond by the catalytic system Pd(OAc)2-phenanthroline in the presence of carbon monoxide has been described [38]. The proposed mechanism includes the electrophilic attack of benzene by an active palladium-containing species to to produce a a-phenyl complex of palladium(ll). Subsequent activation of dioxygen by the Pd-phen-CO complex to form a Pd-OPh complex and its reaction with acetic acid yields phenol. The oxidation of propenoidic phenols by molecular oxygen is catalyzed by [A,A"-bis(salicylidene)ethane-l,2-diaminato]cobalt(ll)[Co(salen)] [39]. 

Selectivity in formation of protective groups may also be achieved by a proper choice of reaction conditions and catalyst. Thus formation of the 3-monothioketal from 3,6-diketones is achieved by dilution of the ethane-dithiol-boron trifluoride reaction mixture with acetic acid. 3-Monocyanohydrins are obtained in good yield from 3,20-diketo-(5a)-pregnanes by diluting the exchange reaction with ethanol. Similarly, dilution of the... 

Reaction mixture pH was maintained by use of 0.1 M 2-[N-Morpholino]ethane sulphonic acid adjusted to pH 6.5 with acetic acid. R.E. - repetitive efficiency (%). 

Deaeetylation. Treatment of the acetylpyrrole 1 with BF3 etherate and ethane-dithiol in acetic acid gives the pyrrole 2 in quantitative yield. This reaction was first observed with the coppcr(ll) complex of the acetylporphyrin 3, which was converted to 4 in this way. The proposed mechanism involves protonation of the dithio-kctnl in situ. 

In continuing this work Drugman 145 used air containing 10 per cent of ozone and found that although ethane was oxidized but slowly at 15° C the reaction was more rapid than with methane. At 100° C. with a large excess of ethane much less acetic acid was formed but more ethanol was recovered from the wash traps. In each instance acetaldehyde was the main reaction product. Drugman concluded from these results that... 

At present there are no well-documented examples of Reactions 2 and 3 although several known compounds could serve as excellent models for these types of reactions. For example, the compounds M2Me2(02-CNR2)4, when heated to > 150°C in vacuo, eliminate ethane and yield residues which, by elemental analyses, can be formulated as M2(02CNR2)4 compounds. Both Mo2(CH2SiMe3)6 and Mo2(OPr )e have been found to react with acetic acid to yield, upon vacuum sublimation (200°C, 10 cmHg), Moo(OAc)4. Here a M-M triple-to-quadruple bond transformation is achieved. Reaction 3, but the detailed reaction pathway and the nature of the eliminated organic compounds are not known. 

These reaction products can be explained on the basis of the pathway shown in Scheme 8.4. This pathway involves an initial photoinduced one-electron transfer in a uranyl formate complex to give UO2 and a formate radical, followed by disproportionation to give and carbon dioxide. The photochemistry of the uranyl ion with either acetic acid or its higher homologues follows a similar type redox pathway. Such a pathway with acetic acid leads to the formation of carbon dioxide, ethane, and carbon dioxide ... 

Thioketals are readily formed by acid-catalyzed reaction with ethane-dithiol. Selective thioketal formation is achieved at C-3 in the presence of a 6-ketone by carrying out the boron trifluoride catalyzed reaction in diluted medium. Selective protection of the 3-carbonyl group as a thioketal has been effected in high yield with A" -3,17-diketones, A" -3,20-diketones and A" -3,l 1,17-triones in acetic acid at room temperature in the presence of p-toluenesulfonic acid. In the case of thioketals the double bond remains in the 4,5-position. This result is attributed to the greater nucleophilicity of sulfur as compared to oxygen, which promotes closure of intermediate (66) to the protonated cyclic mercaptal (67) rather than elimination to the 3,5-diene [cf. ketal (70) via intermediates (68) and (69)]." " ... 

Aminotrimethanephosphonic acid is formed from formamide, acetamide, urea, or alkanenitriles with phosphorous acid [296]. By reaction of monoalkyl phosphite or P406 with glacial acetic acid or the corresponding anhydride ethane-1 -hydroxy-1,1-diphosphonic acid is formed after hydrolysis [297,298]. P406 can be obtained from P4 and 02 in a high yield of 85-90% [299]. 

Participation of adsorbed intermediates can also be shown by the prolonged decay of the potential 011 interruption of the current (Conway and Vijh, 1967a) or by measurement of the time-dependence of the formation of products by carrying out the reaction with pulses of potential of controlled duration (Fleischmann et al., 1966). Thus the formation of ethane in the Kolbe reaction of acetate ions in acid solutions is initially proportional to the square of time as would be predicted for the rate of the step (27) (Fleischmann et al., 1965). 

The photo-Kolbe reaction is the decarboxylation of carboxylic acids at tow voltage under irradiation at semiconductor anodes (TiO ), that are partially doped with metals, e.g. platinum [343, 344]. On semiconductor powders the dominant product is a hydrocarbon by substitution of the carboxylate group for hydrogen (Eq. 41), whereas on an n-TiOj single crystal in the oxidation of acetic acid the formation of ethane besides methane could be observed [345, 346]. Dependent on the kind of semiconductor, the adsorbed metal, and the pH of the solution the extent of alkyl coupling versus reduction to the hydrocarbon can be controlled to some extent [346]. The intermediacy of alkyl radicals has been demonstrated by ESR-spectroscopy [347], that of the alkyl anion by deuterium incorporation [344]. With vicinal diacids the mono- or bisdecarboxylation can be controlled by the light flux [348]. Adipic acid yielded butane [349] with levulinic acid the products of decarboxylation, methyl ethyl-... 

Not all C-H activation chemistry is mediated by transition metal catalysts. Many of the research groups involved in transition metal catalysis for C-H activation have opted for alternative means of catalysis. The activation of methane and ethane in water by the hexaoxo-/i-peroxodisulfate(2—) ion (S2O82) was studied and proceeds by hydrogen abstraction via an oxo radical. Methane gave rise to acetic acid in the absence of external carbon monoxide, suggesting a reaction of a methyl radical with CO formed in situ. Moreover, the addition of (external) CO to the reaction mixture led to an increase in yield of the acid product (Equation (ll)).20... 

Of the synthetic reactions of the alkyl halides that with potassium cyanide, which enabled H. Kolbe to synthesise acetic acid from a methane derivative, has already been mentioned (cf. the preparations on pp. 137 and 254). Of the simpler syntheses that of Wiirtz may be mentioned here. Metallic sodium removes the halogen from two molecules and the two radicles combine. Thus, in the simplest case, ethane is formed from methyl bromide ... 

Ti02, with a band gap of 3.2 eV, was successfully used for the photooxidation of acetate ion in acetic acid, a photochemical version of the Kolbe reaction (Kraeutler et al., 1978). The main products formed were methane and carbon dioxide, in addition to small amounts of ethane. The latter is the major product... 

Other methods for the preparation of acetic acid are partial oxidation of butane, oxidation of ethanal -obtained from Wacker oxidation of ethene-, biooxidation of ethanol for food applications, and we may add the same carbonylation reaction carried out with a cobalt catalyst or an iridium catalyst. The rhodium and iridium catalysts have several distinct advantages over the cobalt catalyst they are much fester and fer more selective. In process terms the higher rate is translated into much lower pressures (the cobalt catalyst is operated by BASF at pressures of 700 bar). For years now the Monsanto process (now owned by BP) has been the most attractive route for the preparation of acetic acid, but in recent years the iridium-based CATTVA process, developed by BP, has come on stream. 

Ozone also reacts with ethane in the gas phase at room temperature. Rather than a direct molecular reaction, however, evidence points to the initiation of radical-chain reactions by the very small O-atom concentrations present in ozone at room temperature. Added oxygen scavenges the radicals and slows the build-up, leading to induction periods which may be in excess of 3 h. Recent advances in mechanistic investigations of gas-phase ozonolysis of alkanes have been reviewed. Oligomeric peroxides dominate the products of oxidation of nitrotoluenes with ozone in acetic acid. °... 

The submitters employed 75 g. (0.5 mole) of the liquid 1 2 boron trifluoride-acetic acid complex obtained from Harshaw Chemical Company. Since the checkers were unable to obtain this complex from a commercial source, they prepared the solid 1 1 complex following published directions.3 4 A 2-1. threenecked flask is fitted with a mechanical stirrer, a gas outlet tube, and a gas inlet tube extending to the bottom of the flask. A solution of 230 ml. of acetic acid in 750 ml. of 1,2-dichloro-ethane is added to the flask and a stream of boron trifluoride gas is passed through the reaction flask while the solution is stirred and cooled with an ice bath. After approximately 1 hour, when the mixture is saturated, the addition of boron trifluoride is stopped and the insoluble 1 1 boron trifluoride-acetic acid complex is rapidly collected on a filter, washed with 200 ml. of... 

The stoichiometric equivalents of halofluorides have been recently applied to transform alkylene dithioacetals into gcm-difluorides.70-71 Dithioacetals such as 1,3-dithiolanes and 1,3-dithianes arc readily obtained from the corresponding carbonyl compounds by the reaction with ethane-1,2-dithiol or propane-1,3-dithiol in the presence of the complexes boron trifluoride-bis(acetic acid) or boron trifluoride-diethyl ether. Using a two-step procedure, a range of aldehydes and ketones can be converted into gem-difluorides under mild conditions. 

Acetone, Nitration. Krauz Stepanek(Ref 1) attempted to prepare terrani from ethane by nitration of acetone, but failed, instead, they obtained (after treating the resulting product with a silver salt) a very expl solid claimed to be Ag salt of acetylmethylnitrolic acid, also called a-nitro - a -isonitroso-acetone. Hass Hudgin(Ref 3) nitrated acet, using a vapor-phase nitration technique described in Ref 2. The high-boiling fractn from the nitration gave an odor of acetic acid, an acidic reaction in aq soln, a red color with ferric chloride and a yel salt with Ag nitrate soln,... 

Even methane, the least reactive alkane, was shown to undergo carboxylation under superacidic conditions.115,176 The formation of carboxylated products (acetic acid and methyl acetate) from methane was first observed by Hogeveen and coworkers by trapping methyl cation formed in SbF5 (60°C, 50 atm CO pressure) followed by quenching with H20 or MeOH. The intermediate methylcarboxonium ion (CH3CO+) and CH3CH2CO+ formed in a similar reaction of ethane were identified by NMR spectroscopy.176,177... 

Chloroacetic Acid (ClCHiCOOHf. [CAS 79-11-8 J. Chloroacelic acid can be synthesized by the radical chlorination of acetic acid, treatment of trichloroethylene with concentrated H S04. oxidation of 1.2-dichloro ethane or chloroaceialdehyde. amine displacement from glycine, or chlorination of ketene. It behaves as a very strong monobasic acid and is used as a strong acid catalyst for diverse reactions. The Cl function can be displaced in base-catalyzed reactions. For example, it condenses with alkoxides to yield alkoxyacetic acids CICH COOH... 

A prototype study for this issue was performed for the conversion of ethane to acetic acid [71] and the same group highlighted in an earlier comparative study of C3 oxidation [54] that, although initial propane activation is a difficult step, subsequent reactions associated with either excessive residence times of intermediates or with branching of reaction sequences into total oxidation may interfere with the overall selectivity to partial oxidation products. 

Table 9.1 summarizes catalyst compositions and corresponding performances. The oxidation of ethane to acetic acid is now commercial an industrial plant is installed, with the technology developed by Saudi Basic. Elements that have contributed to the successful development of the process are (1) the discovery of a catalytically active compound, the multifunctional properties of which can be modified and tuned to be adapted to reaction conditions through incorporation of various elements (2) the stability of the main products, ethylene and acetic acid, which do not undergo extensive consecutive degradation reactions (3) the possibility of recycling the unconverted reactant and the major by-product, ethylene (4) the use of reaction conditions that minimize the formation of CO and (5) an acceptable overall process yield. 

Similarly, with the same type of photocatalyst (Pt/TiC>2 or Fe2C>3) the decomposition of levulinic (4-oxopentanoic) acid in oxygen-free aqueous solution has been investigated in detail (60). In addition to the decarboxylation reaction, oxidative C-C scissions led to propionic and acetic acids (further converted into methane and ethane) and reductive cleavages to acetone and ethanal. The formation of acetone was apparently favoured by higher Pt contents (however product distributions referred to equal illumination durations and not to equal conversions). It was suggested that the variety of products resulted from the presence of two functional groups in levulinic acid. The quantum yield was probably of the order of 5 x IQ-3. 

Micro structured wells (2 mm x 2 mm x 0.2 mm) on the catalyst quartz wafer were manufactured by sandblasting with alumina powder through steel masks [7]. Each well was filled with mg catalyst. This 16 x 16 array of micro reactors was supplied with reagents by a micro fabricated gas distribution wafer, which also acted as a pressure restriction. The products were trapped on an absorbent plate by chemical reaction, condensation or absorption. The absorbent array was removed from the reactor and sprayed with dye solution to obtain a color reaction, which was then used for the detection of active catalysts by a CCD camera. Alternatively, the analysis was also carried out with a scanning mass spectrometer. The above-described reactor configuration was used for the primary screening of the oxidative dehydrogenation of ethane to ethylene, the selective oxidation of ethane to acetic acid, and the selective ammonoxidation of propane to acrylonitrile. 

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