Synthesis of Carbonates

The development of environmental processes based on the utilization of naturally abundant carbon resources such as carbon dioxide has gained considerable attention in recent years. Organic carbonate synthesis using carbon dioxide is one of the promising reactions in this respect. Organic carbonate compounds have been used as both a reactive intermediate and an inert solvent. 

Dimethyl carbonate (DMC) can be synthesized from epoxide compounds such as ethylene oxide or propylene oxide by a two-step reaction (Fig. 13.1). In the first step the epoxide reacts with CO2, producing a corresponding cyclic carbonate. In the second step, the carbonate is transesterified with methanol to DMC and a corresponding glycol. 

CeOg with several of the metal oxides does not appear to be a good catalyst for this reaction. Basic metal-oxide catalysts have high activity and selectivity in the reaction of epoxides and COg to the corresponding cyclic carbonates and in transesterification with methanol. Of the catalysts examined, MgO and CeOg are the best catalysts and are active 

Step 2 cyclic carbonate 25 mmol methanol 200 mmol CO, 8 MPa catalyst 0.5 g (DMF 2 ml) temperature 150°C reaction time 4 h. 

Abimanyu etal. studied the synthesis of DMC by ethylene carbonate transesterification with methanol (step 2) with various MgO-CeOs mixed oxide catalysts at 150°C. They showed that a high ethylene carbonate conversion of 64% (DMC selectivity of 95%) could be obtained by a catalyst with a cerium content around 25 mo %P 

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The chemical synthesis of carbon-containing molecules has been a very important field of scientific work and endeavor for over a centuiy However, the subject is still far aw ay from being fully developed. One of the major reasons for this is the almost unlimited number of organic structures which can exist as discrete compounds. On the other hand there has been a continuing growth in the ability of chemists to construct increasingly complex molecules. 

R. Engel, Synthesis of Carbon—Phosphorus Ponds, CRC Press, Boca Raton, Fla., 1988. 

The earliest method for manufacturiag carbon disulfide involved synthesis from the elements by reaction of sulfur and carbon as hardwood charcoal in externally heated retorts. Safety concerns, short Hves of the retorts, and low production capacities led to the development of an electric furnace process, also based on reaction of sulfur and charcoal. The commercial use of hydrocarbons as the source of carbon was developed in the 1950s, and it was still the predominate process worldwide in 1991. That route, using methane and sulfur as the feedstock, provides high capacity in an economical, continuous unit. Retort and electric furnace processes are stiU used in locations where methane is unavailable or where small plants are economically viable, for example in certain parts of Africa, China, India, Russia, Eastern Europe, South America, and the Middle East. Other technologies for synthesis of carbon disulfide have been advocated, but none has reached commercial significance. 

The catalytic method provides the basis for synthesis of carbon tubules of a large variety of forms. Straight tubules, as well as bent and helically wound tubules, were observed. The latter regular helices of fullerene diameter can be of special interest from both theoretical and practical points of view. 

The use of a stable glow discharge for the synthesis of carbon nanotubes... 

Large-Scale Synthesis of Carbon Nanotubes by Pyrolysis... 

Hernadi, H., Fonseca, A., Nagy, J. B. and Bemaerts, D., Catalytic synthesis of carbon nanotubes. In Supercarbon, Synthesis, Properties and Applications, ed. S. Yoshimura and R. P. H. Chang. Springer-Verlag, Heidelberg, 1998, pp. 75 91. 

Fowler, J S, Wolf, A P The Synthesis of Carbon-II, Fluorine 18 and Nitrogen 13 Labeled Radiotracers for Biomedical Applications, Mono graph NAS-NS-3601, Technical Information Center, U S Department of Energy... 

Use data in Table 7.3 or Appendix 2A to calculate the standard entropy change for each of the following reactions at 25°C. For each reaction, interpret the sign and magnitude of the reaction entropy, (a) The synthesis of carbon disulfide from natural gas (methane) CH4(g) + 4 S(s, rhombic) - CS2(1) +... 

Engel, R. Synthesis of Carbon-Phosphorus Bonds, CRC Press Boca Raton, FL 1988, and references cited therein. 

Husein, F., Imad, Zhou, YuanZhong, Li, Fan, Ryne, C., AUen, Chung Chan, Jacob, I., Kleiman, Yu, Gudimenko, and Clark, V, Cooper, Synthesis of Carbon Nitride Thin Film by Vacuum Arcs, Mater. Sci. Eng., A, Vol. 209,1996, pp. 10-15. 

If in the synthesis of carbonic esters with CDI one alcohol component is replaced by a hydroperoxide, peroxycaibonates are formed. 2651 More details on this reaction are given in Section 3.11. 

West TO, Marland G. A Synthesis of Carbon Sequestration, Carbon Emissions and Net Carbon Flux in Agriculture Comparing Tillage Practices in the United States. Agriculture, Ecosystems and Environment. 2002 91(l-3) 217-232. Doi 10.1016/ S0167-8809(01)00233-X... 

Wang M, Gao M, Miller KD et al (2009) Simple synthesis of carbon-11 labeled styryl dyes as new potential PET RNA-specific, living cell imaging probes. Eur J Med Chem 44 2300-2306... 

Figure 8.4 Nitrilase-catalyzed conversion of (5)-3-(thiophen-2-ylthio)butanenitri le to (S)-3,3,3-trifluoro-2-hydroxy-2-methyl-propionamide, an intermediate in the synthesis of carbonic anhydrase inhibitor Dorzolamine ...

The geological process of the formation of serpentine from peridotite probably involves the synthesis of carbon compounds under FTT conditions (see Sect. 7.2.3). The hydrogen set free in the serpentinisation process can react with CO2 or CO in various ways. The process must be quite complex, as CO2 and CO flow through the system of clefts and chasms in the oceanic crust and must thus pass by various mineral surfaces, at which catalytic processes as well as adsorption and desorption could occur. 

Engel R (1988) Synthesis of carbon-phosphorus bonds. CRC, Boca Raton, FL... 

New simple methods for synthesis of carbon-carbon, as well as carbon-carbon-Ti02 composites and carbon nanoscrolls were proposed making use of readily available graphite intercalation compounds. 

The aluminum is incorporated in a tetrahedral way into the mesoporous structure, given place to Bronsted acidic sites which are corroborated by FTIR using pyridine as probe molecule. The presence of aluminum reduces the quantity of amorphous carbon produced in the synthesis of carbon nanotubes which does not happen for mesoporous silica impregnated only with iron. It was observed a decrease in thermal stability of MWCNTs due to the presence of more metal particles which help to their earlier oxidation process. 

The synthesis of carbon templated mesoporous tin MFI catalysts with different Si/Sn was carried out using microwave and in typical synthesis methodology TEOS, TPAOH, [Sn(C5H70)2]2]Cl2, ethanol and water were employed where the molar composition of the reaction mixture was 0.06 TPAOH 0.67 H20 0.028 TEOS 1.3 g EtOH X mg of tin precursor (X = 85, 63, 42, 21 mg). This synthesis mixture was stirred for 90 min at room temperature and then Black pearl 2000 carbon (10% wt. of TEOS) was added and again stirred for 4 h vigorously. The crystallization of C-meso-Sn-Silicalite was performed in a Teflon cup placed in a microwave oven (MARS-5, CEM, maximum power of 1200 W). 

A rapid synthesis of carbon-14 labeled [l-14C]levulinic acid from simple building blocks has been demonstrated by Johansen and coworkers (Scheme 6.172) [324], In all three of the synthetic steps, starting from bromo[l-14C]acetic acid, microwave heating was used to accelerate the reactions, allowing a total preparation time of less than 1 h. The labeled levulinic acid was subsequently transformed into (5Z)-4-bromo-5-(bromomethylene)-2(5H)-furanone in a bromination/oxidation sequence (not shown), a potent quorum sensing inhibitor. 

Synthesis of carbon-phosphorus bonds / Robert Engel, JamieLee Iolani Cohen — 2nd ed. p. cm. 

It has been nearly 17 years since Synthesis of Carbon-Phosphorus Bonds was written. In the interim, numerous significant advances have been made regarding approaches toward the syntheses of organophospho-rus compounds. While these new approaches have not necessarily replaced the older, established methods, they provide a major supplement to them. 

Synthesis of Carbon-Phosphorus Bonds, Engel, R., CRC Press, Boca Raton, FL, 1988 — The first edition of the current work, it presents a survey of methods for forming carbon-phosphorus bonds with detailed examples to the date of publication. 

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