Hydrocarbons => alkyl halides

Reactivity The mobile phase must not react with the analytical sample or column packing. This does not present a major limitation since many relatively unreactive hydrocarbons, alkyl halides, and alcohols are suitable. 

Hydrocarbons, alkyl halides, ethers, many esters... 

Lithium arene radical anions and dianions, [ArH2] Li and [ArH] 2 Li", can react with acidic hydrocarbons , alkyl halides or alkyl sulfides to form organolithiums via electron transfers. 

The physical technique with the greatest potential for synthetic applications of Ritter-type reactions is electrochemistry. A selection only of examples is discussed here. Synthetic chemists unfamiliar with this technique will find the review by Eberson and Nyberg an informative and entertaining introduction to this area. Electrochemical Ritter reactions may be performed through anodic substitution of a hydrogen by the nitrile, followed by hydrolysis of the nitrilium ion intermediate, as shown in Scheme 42. The majority of reactions investigated have been anodic acetamidations using hydrocarbons, alkyl halides, esters or ketones as the substrate. In some cases, such as reaction of the adamantane derivatives (83), the yields of amide product are excellent (Scheme 43). 

Hydroformylation is usually carried out under catalytic conditions. The alkene, catalyzed by metal complexes under carbon monoxide and hydrogen in hydrocarbon, alkyl halide or ether solvent, generates the hydroformylation product. Rhodium catalysts are preferred for laboratory syntheses because of their higher activity and selectivity. Improvements in regioselectivity and yields have been found when the reaction is carried out in the presence of added donor ligands such as trialkylphosphines, or under UV irradiation. Catalysts supported on polymers have been used for easy separation of product and reuse of catalysts. 

Many esters are soluble in cold concentrated sulphuric acid. This property serves to distinguish them from hydrocarbons, alkyl halides, and many other compounds. 

Calcium chloride Ethers, esters, hydrocarbons, alkyl halides Alcohols, amines, phenols, amides, ketones 0.3 None 1500... 

Phosphorus pentoxidfi Hydrocarbons, alkyl halides Alcohols, ketones, amines 0.5 None 0.2... 

As shown in Table 9.1, aldehydes, ketones, carboxylic acids, and their derivatives have been produced from other organic compounds (hydrocarbons, alkyl halides, and alcohols) and have been already been introduced as part of the discussion of those other compounds. Therefore, the material of Table 9.1 serves both as a reminder of reactions already discussed and thus, presumably, known to the reader, and as a device to foreshadow that which is yet to come. Thus, in addition to a plethora of new reactions that will expand the philosophy of things in heaven and earth, it remains important to remember that the organic compounds already discussed can themselves produce or be produced from aldehydes, ketones, and/or carboxylic acids (and or their derivatives). 

The reactions of atomic F, Cl, Br, and I with a large number of compounds such as hydrocarbons, alkyl halides, aldehydes, ketones, and acids have been studied [232]. 

A negative reaction is given by hydrocarbons, alkyl halides, aldehydes, ketones, ethers, amino acids, nitro compounds, and nitriles. The test is suitable for the detection of alcohols in other solvents. 

Wuftz synthesis Alkyl halides react with sodium in dry ethereal solution to give hydrocarbons. If equimolecular amounts of two different halides are used, then a mixture of three hydrocarbons of the types R — R, R — R and R —R, where R and R represent the original radicals, will be formed. The yields are often poor owing to subsidiary reactions taking place. 

Sheppard N and De La Cruz C 1998 Vibrational spectra of hydrocarbons adsorbed on metals. Part II. Adsorbed acyclic alkynes and alkanes, cyclic hydrocarbons including aromatics and surface hydrocarbon groups derived from the decomposition of alkyl halides, etc Adv. Catal. 42 181-313... 

The Friedel-Crafts Reaction, in which an aromatic hydrocarbon reacts with an alkyl halide under the influence of aluminium chloride ... 

The Fittig Reaction, in which sodium reacts with a mixture of an aryl and an alkyl halide, forming the sodium halide and the corresponding hydrocarbon ... 

Cold concentrated sulphuric acid will remove unsaturated hydrocarbons present in saturated hydrocarbons, or alcohols and ethers present in alkyl halides. In the former case soluble sulphonated products are formed, whilst in the latter case alkyl hydrogen sulphates or addition complexes, that are soluble in the concentrated acid, are produced. 

When an alkyl halide is treated with sodium, the main product is the paraffin hydrocarbon. The final result may be represented by the equation ... 

Friedel and Crafts reaction. alkyl halide condenses with an aromatic hydrocarbon in the presence of anhydrous aluminium chloride to yield, in the first instance, a hydrocarbon in accordance with the following scheme —... 

Removal of unsaturated hydrocarbons, of alcohols and of ethers from saturated hydrocarbons or alkyl halides by washing with cold concentrated sulfuric acid. 

Sodium (metal). Used as a fine wire or as chips, for more completely drying ethers, saturated hydrocarbons and aromatic hydrocarbons which have been partially dried (for example with calcium chloride or magnesium sulfate). Unsuitable for acids, alcohols, alkyl halides, aldehydes, ketones, amines and esters. Reacts violently if water is present and can cause a fire with highly flammable liquids. 

Nylons 46, 6, 66, 610, 11 and 12 are polar crystalline materials with exceptionally good resistance to hydrocarbons. Esters, alkyl halides, and glycols have little effect. Alcohols generally have some swelling action and may in fact dissolve some copolymers (e.g. nylon 66/610/6). There are few solvents for the nylons, of which the most common are formic acid, glacial acetic acid, phenols and cresols. 

Organolithium compounds are sometimes prepared in hydrocarbon solvents such as pentane and hexane, but nonnally diethyl ether is used. It is especially important that the solvent be anhydrous. Even trace amounts of water or alcohols react with lithium to form insoluble lithium hydroxide or lithium alkoxides that coat the surface of the metal and prevent it from reacting with the alkyl halide. Furthennore, organolithium reagents are strong bases and react rapidly with even weak proton sources to fonn hydrocarbons. We shall discuss this property of organolithium reagents in Section 14.5. 

Grignard reagents are rapidly hydrolysed by water or acid to give the parem hydrcxatbon, RH, but this reacdon is rarely of synthedc importance. Hydrocarbons can also be syndiesized by nucleophilic displacement of halide ion from a reacdve alkyl halide, e.g. 

This reaction can be used for the synthesis of hydrocarbons but it may also take place as a side-reaction during generation of a Grignard reagent from an alkyl halide and magnesium, then leading to formation of undesired side-products. 

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