Formats dimethoxymethane

The conventional electrochemical reduction of carbon dioxide tends to give formic acid as the major product, which can be obtained with a 90% current efficiency using, for example, indium, tin, or mercury cathodes. Being able to convert CO2 initially to formates or formaldehyde is in itself significant. In our direct oxidation liquid feed fuel cell, varied oxygenates such as formaldehyde, formic acid and methyl formate, dimethoxymethane, trimethoxymethane, trioxane, and dimethyl carbonate are all useful fuels. At the same time, they can also be readily reduced further to methyl alcohol by varied chemical or enzymatic processes. 

Still several problems remain unsolved to make the DSHP-HPPO process economically viable (i) safety the reaction of H2 with O2 in the presence of a flammable solvent (methanol) puts high hurdles on safety (ii) removal of acid and bromide the Bronsted acid and the bromide needed to produce HP from the elements have to be removed before the generated H P solution can be used for epoxidation (iii) solvent recycle after the generated H P solution has been used for epoxidation, the methanol has to be separated and recycled. During work-up some additional by-products are formed formaldehyde, acetaldehyde, propionaldehyde, methyl formate, dimethoxymethane, 1,1-dimethoxyethane and 1,1-dimethoxypro-pane. These compounds are difflcult to separate (many make azeotropes with methanol), so the recovered methanol will be contaminated. However, even small amounts of aldehydes or formates can poison the Pd or Pd/Au catalyst. Additional equipment needed to solve these problems will increase the investment costs. 

Palladium oxidizes methyl acrylate in the presence of methanol to form 3-methoxy methyl acrylate and equimolar amounts of water with a reaction rate R3. Reduced Pd is reoxidized by the Fe/Gu cocatalyst with a reaction rate R2 producing a reduced Fe/Gu cocatalyst, which is reoxidized by oxygen. The palladium catalyst is also responsible for the formation of by-products from oxidation of methanol (methyl formate, dimethoxymethane). 3-Methoxy methyl acrylate... 

Isoprene [78-79-5] (2-methyl-1,3-butadiene) is a colorless, volatile Hquid that is soluble in most hydrocarbons but is practically insoluble in water. Isoprene forms binary azeotropes with water, methanol, methylamine, acetonitrile, methyl formate, bromoethane, ethyl alcohol, methyl sulfide, acetone, propylene oxide, ethyl formate, isopropyl nitrate, methyla1 (dimethoxymethane), ethyl ether, and / -pentane. Ternary azeotropes form with water—acetone, water—acetonitrile, and methyl formate—ethyl bromide (8). Typical properties of isoprene are Hsted in Table 1. 

Zn, (CH30)2CH2, BrCH2C02Et, 80-82% yield. Formation of the meth-oxymethyl thioether with dimethoxymethane avoids the use of the carcinogen chloromethyl methyl ether. The reaction forms an intermediate zinc thiolate, which then forms the monothioacetal. 

In 1911, Ame Pictet and Theodor Spengler reported that P-arylethyl amines condensed with aldehydes in the presence of acid to give tetrahydroisoquinolines. Phenethylamine 6 was combined with dimethoxymethane 7 and HCl at elevated temperatures to give tetrahydroisoquinoline 8. Soon after, the Pictet-Spengler reaction became the standard method for the formation of tetrahydroisoquinolines. 

Surface-enhanced infrared study of catalytic electrooxidation of formaldehyde, methyl formate, and dimethoxymethane on platinum electrodes in acidic solution. 

Miki A, Ye S, Sensaki T, Osawa M. 2004. Surface-enhanced infrared study of catal)4ic electio-oxidation of formaldehyde, methyl formate, and dimethoxymethane on platinum electrodes in acidic solution. J Flectroanal Chem 563 23-31. 

A conmercial catalyst frcm Harshaw was used, a 3 1 mixture of molybdenum trioxide and ferric molybdate, as well as the two separate phases. Kinetic experiments were done previously in a differential reactor with external recycle using these same catalysts as well as several other preparations of molybdenun trioxide, including supported samples. Hie steady state kinetic experiments were done in the temperature range 180-300 C, and besides formaldehyde, the following products were observed, dimethylether, dimethoxymethane, methyl formate, and carbon-monoxide. Usually very little carbon dioxide was obtained, and under certain conditions, hydrogen and methane can be produced. 

In particular, 1,3-dithiane prepared from dimethoxymethane (methylal) and pro pane-1,3-dithiol in the presence of boron trifluoride-etherate,237 and 2-alkyl-1,3-dithianes prepared similarly from aldehydes,2383 are important acyl anion equivalents. These and other uses are discussed in Sections 5.7.5, p. 596, and 6.6.1, p. 909. A wide-ranging review of the reversal of polarity of the carbonyl group through the formation of these sulphur-containing reagents has emphasised their value in organic synthesis.2388... 

PC = propylene carbonate DN = 1,3-dioxolane EC = ethylene carbonate 3-MeS-3 = methyl sulfolane DME = dimethoxy ethane THF = tetrahydrofuran S = sulfolane DMSO = dimethyl sulfoxide, DEE = diethyl ether, 2-Me-F = 2 methyl furan 2-MeDN = 2-methyl 1,3-dioxolane MA = methylacetate DMM = dimethoxymethane 2-MeOTHF = 2 methoxytetrahydrofuran BL = y-butyrolactone NM = nitromethane AN = acetonitrile MF = methyl formate DEC = diethyl carbonate DMC = dimethyl carbonate. 

One of the mildest methods for preparing methylene acetals involves reaction of a diol with dimethoxymethane in the presence of a suitable activating agent such as phosphorus pentoxide,176 trimethylsilyl Inflate.177 or lithium bromide and p-toluenesulfonic acid.178 The reaction is also used to make methoxymethyl ethers (see section 4.4,1) from alcohols. Scheme 3,95 illustrates the simultaneous formation of a methoxymethyl ether and a methylene acetal from Shikimic Acid.169 The reaction was adapted to the synthesis of the methylene acetal moiety of the marine antitumour agent Mycalamide B [Scheme 3.96],179... 

DME, Dimethyl ether MF, methyl formate DMM, dimethoxymethane. Including a small amount of C2 and Cj hydrocarbons. 

Early studies on titania powders showed that methanol generated methyl formate as the principle photooxidation product. Molybdena- and vanadia-modified Ti02 catalysts demonstrated at least an eighty percent drop in activity relative to pure titania, although selectivity to dimethoxymethane (and thus suppression of further oxidation products) was almost total [87]. 

First, the electrochemical reduction of COj on the Cu electrode was studied in a COj-methanol medium at various pressures of COj. Under both atmospheric and high pressure, CO, CH, CjHj, and Hj were detected as products in the gas phase. In the liquid phase, methyl formate, HCOOCHy and dimethoxymethane, CH3OCH2OCH3, were detected. Cyclic voltammograms at various CO pressures are presented in Figure 3. The cathodic current was observed with an onset potential of -1.0 V under 1 atm of N. A shoulder was observed around -1.2 V during the scan in the negative direction. When was replaced with 1 atm of... 

Performances obtained in the ODH of methanol to formaldehyde Depending on the operative conditions adopted, the main products observed were formaldehyde and dimethoxymethane while lower amounts of methyl formate and CO2 were also found. In Fig.2, a comparison of the conversion, obtained with the catalysts containing an increasing amount of vanadium on the same support TSm, is reported. At a fixed temperature, the increase in vanadium content results in an increase of methanol conversion. Fig.3 reports... 

A comparison of the i>E response for the three fuels investigated is illustrated in Fig 1.45. Since both trimethoxymethane and dimethoxymethane behave in a similar manner to concentrated solutions of methanol, the comparison of fuels was made using less concentrated solution of the formates compared with the standard 1.0 M methanol solution, in addition, since the permeation of energetic fuels such as trimethoxymethane and dimethoxymethane to the cathode result in greater parasitic current densities compared to methanol, the lower concentrations were found desirable due to the lower crossover rates. As shown in Fig. 1.45, dimethoxymethane performed almost identically at low current densities (>150 mA/cm 90 0) with methanol. At higher current densities, the methanol shows the best... 

Acetone, bromoethane, butane, chloroethane, 2-chloropropane, 1,3-cyclopenta-diene, dibromodifluoromethane, 1,1-dichloroethane, 1,1-dichloroethene, 1,2-di-chloro-l,l,2,2-tetra luoroethane, diethylether, dimethoxymethane, dimethylpro-pane, 1,3-epoxypropane, ethyl formate, glyoxal, methyl acetate, methylbutane, methyl formate, methylpropane, -pentane, propanal. 

A system has been described for the formation of dimethyl carbonate via the phosgene-free route of oxidative carbonylation of methanol [(Eq. (8)] catalyzed by PdCl2 in [BMIMKPFjj (110 C, total pressure 10 MPa, 1 h) [48]. Conversions were generally low (< 7%) and did not improve with increased reaction time, although the selectivity to dimethyl carbonate dropped. Dimethoxymethane was the major product but selectivities of dimethyl carbonate of up to 25% were possible with an O2/CO2 ratio of 29 71. Neither the pressure nor the temperature had dramatic effects upon the yield or selectivity, although the reaction was slower at lower temperatures. The reaction was repeated three times under the optimum conditions in a repetitive batch process. The rate remained constant, but there was a slight drop in selectivity. 

The first work [64] described the synthesis of nonadecane-l,19-diol and tricosane-1,23-diol from oleic acid and erucic acid, respectively. For the synthesis of diacetals starting from diols and dimetoxymethane, use of 20 mol% methanesulfonic acid as a catalyst produced the desired 2,4,24,26-tetraoxaheptacosane from nonadecane-1,19-diol at 85% yield. Also, use of 20 mol% trifluoromethanesulfonic acid as a catalyst led to the formation of 2,4,28,30-tetraoxahentriacontane from tricosane-1,23-diol at 79% yield. Difunctional acetal monomers were then subjected to AMP at 80-100 "C, 2-4 mol% of p-toluenesulfonic acid as a catalyst, and reduced pressure to remove the dimethoxymethane byproduct. Authors obtained polymers with Mn values of 17 and 22 kDa, with the higher value arising from the longer-chain diol/diacetal. 

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