Carbon acetates

Bromination of aldehydes (qv) is more compHcated because bromination can take place on the aldehyde carbon as weU as the a-carbon. Acetals are brominated satisfactorily in cold chloroform solution in the presence of calcium carbonate, which reacts with the hydrogen bromide formed (24). 

Sodium carbonate Acetic anhydride Hydrogen chloride Ethylene oxide... 

Quantitative analysis of anions from a prenatal vitamin formulation chloride, sulfate, nitrate, citrate, fumarate, phosphate, carbonate, acetate (see also cations)... 

Nitric acid. Kerosene, Ammonium picramate. Ethanol Sodium picramate. Hydrochloric acid. Sodium nitrate Nitric acid. Diethanolamine, Acetic anhydride. Acetyl chloride. Acetone, Potassium carbonate Acetic anhydride. Hydrochloric acid. Diethanolamine, Methylene chloride. Nitric acid. Sodium bicarbonate Nitric acid. Diethanolamine, Hydrogen chloride. Sodium bicarbonate Diisopropylamine, Nitric acid... 

The third form of C02 coordination involves a generally irreversible reaction with other ligands or external reactants, leading to C02 coordination as carbonate, acetate, etc. Much of this coordination mode will be dealt with in the sections on C02 insertion reactions. 

V-Formylkynurenine is one of the 16 autoxidation products of tryptophan (51) (Fig. 8). The dye-sensitized photo-oxygenation of tryptophan in sodium carbonate - acetic acid buffer (pH 7) gave TV-for my Iky n urenine as the major product (52). This is also the oxidation product of tryptophan with hydrogen peroxide (53) and with ozone (54). This is an interesting case the same degradation impurity can be obtained in different ways, probably... 

Sodium carbonate Acetic anhydride Cinchonidine Hydrogen... 

The conversion was quantitative (>95%). The methanolic solution was cooled and neutralized with a small excess of sodium carbonate. Acetals were extracted from methanol with light petroleum. For structural studies, acetals were oxidized to the corresponding acids by the action of chromic oxide in glacial acetic acid. The esters produced by the esterification with methanolic HC1 were chromatographed and compared with standards. Schogt et al. [66] used silver oxide for the oxidation and diazomethane for the esterification. 

The fatty adds of common triglycerides are long, unbranched carboxylic acids with about 12 to 20 carbon atoms. Most fatty acids contain even numbers of carbon atoms because they are derived from two-carbon acetic acid units. Some of the common fatty acids have saturated carbon chains, while others have one or more carbon-carbon double bonds. Table 25-1 shows the structures of some common fatty acids derived from fats and oils. 

Which of these are strong acids Hydrochloric, sulfuric, carbonic, acetic (2)... 

By holding uniform-sized PVC samples at constant temperatures and periodically weighing them, we were able to show differences in release rates of 14-carbon acetates, alcohols, and aldehydes. Table V summarizes these data, and shows that the aldehyde component is released about twice as fast as the acetate, with the alcohol being emitted at an intermediate rate. 

Table V. Release rates of 14-carbon acetate, alcohol, and aldehyde pheromone components from a PVC matrix.

Various fluorides may be precipitated from aqueous solution for use as constituent powders in solid state reactions. Co-precipitation offers very elegant access to intimate mixtures, but the actual products are strongly dependent on the fluoride ion activity within the solution but also on the stability constants of the respective metal complexes. Accordingly, not only anhydrous fluorides are obtained, but also hydrated fluorides or hydroxide fluorides, which may be very difficult to convert to pure fluorides. As noted already [3], reactive compounds, e.g. carbonates, acetates, oxalates, hydroxides etc., which quite easily dissolve in acidic HF solutions, are the preferred starting materials for fluoride syntheses. In contrast, many oxides which have been heated to rather high temperature are frequently unreactive and may not dissolve at all. To enhance reactivity but also improve crystallinity of the product, it has proved useful to perform reactions above the boiling point of water in adapting the hydrothermal method, which has already been shown to be useful in the recrystallisation of materials which are more or less insoluble at ambient temperatures and pressures. Up to about 240°C even PTFE vessels may be used. A number of selected examples with respective reaction conditions are listed in Table 3. 

Aqua ions are known but not very stable. Substitution of Pt in aqueous solution is sometimes zero-order in the added ligand, L, or can have both L-dependent and L-independent contributions to the rate, probably because intermediate formation of an unstable aqua complex is the rate-determining step for the L-independent pathway. A large number of O-donors, particularly anionic ones, give stable complexes, for example, carbonate, acetate, oxalate, acetylacetonate, and alkoxide. Tetrameric platinum(II) acetate is formed by formic acid reduction of Pt solutions in acetic acid. It does not appear to be a very useful synthetic precursor for Pt chemistry. The acetylacetonate [Pt(acac)2] is monomeric and square planar. 

These by-products are suppressed by hydrogenating in an acid medium, e.g., in the presence of carbonic, acetic, or oxalic acids. ... 

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