From inorganic halides Esters

In particular cases the reaction of electrophilic cyclopropanes with inorganic halides gives rise to ring cleavage products. In DMF-0.1 M LiBr at 126°C in a sealed tube the cyclopropane 488 affords a mixture of 670 and 671. The latter product arises from bromide ion attack on the methyl group of the ester to produce methyl bromide and the carboxylate anion which cyclizes, while the former cyclopropane compound 670 results... 

Photoinitiation is not the only access to this chemistry, e.g., cathodic induced reduction or the use of alkali metals or other inorganic reducing reagents are also possible, but irradiation often is advantageous for preparative purposes. Since this is a chain process, the use of low-power lamps or a low quantum yield initiation step are not necessarily a limitation. Due to the requirement of a fast cleavage at the radical anion stage, aryl halides are by far the most used reagents, in particular iodides and, to a lower extent, bromides. Nucleophiles are carbanions from sufficiently acidic hydrocarbons, e.g., 1, 3-diphenylindane, fluorene or triphenylmethane [35-37] or, more commonly enolates from ketones [38], esters [39], MA -dialkylamides [40], nitriles [41]. C-C bond formation is obtained also with phenoxide or naphthoxide anions [42,43]. A few representative examples of synthetic applications of the S l... 

Strictly speaking the alkyl halides are esters of the halogen acids, but since they enter into many reactions (t.g., formation of Grignard reagents, reaction with potassium cyanide to yield nitriles, etc.) which cannot be brought about by the other eaters, the alkyl halides are usually distinguished from the esters of the other inorganic acids. The preparation of a number of these is described below. 

These reactions are most important for the preparation of acyl fluorides. " Acyl chlorides and anhydrides can be converted to acyl fluorides by treatment with polyhydrogen fluoride-pyridine solution" or with liquid HF at — 10°C. Formyl fluoride, which is a stable compound, was prepared by the latter procedure from the mixed anhydride of formic and acetic acids. Acyl fluorides can also be obtained by reaction of acyl chlorides with KF in acetic acid or with DAST. Carboxylic esters and anhydrides can be converted to acyl halides other than fluorides by the inorganic acid halides mentioned in 10-77, as well as with PhsPXa (X = Cl or but this is seldom done. Halide exchange can be carried out in a... 

The esters of a number of inorganic acids are known. Those derived from the strong acids may be prepared directly from the acid and alcohol. In the case of the weak acids the esters can be prepared as the result of the interaction of the silver salt of the acid with an alkyl halide for example, ethyl sulphite may be made by the reaction expressed by the equation,... 

The distribution of dissolved substances in two solvent phases is employed on a large scale in the industrial separation of mixtures of substances. Examples are the removal of unsaturated constituents from vegetable oils with furfurol or methanol, the purification of animal and vegetable oils with liquid propane, and the removal of waxes from lubricants with liquid propane or ketones. Penicillin is similarly concentrated with methyl isobutyl ketone, and aqueous glycerol is purified with xylene. Preparative and analytical separations are also performed by liquid-liquid extraction. Inorganic salts can be extracted from aqueous solutions with suitable solvents, such as ethers, ketones, and esters. This method is particularly efficient for metal halides and nitrates, e.g., the separation of uranium compounds from aqueous solutions or the fractional extraction of rare earths. 

An outstanding point which emerged from my early work on the interaction of hydroxy compounds and inorganic nonmetal halides, such as thionyl and phosphorus halides, was the vital function of the hydrogen halide formed in the reaction pattern. The interaction of hydrogen halides with alcohols, esters, and ethers has also operational importance. 

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