Preparation reaction with alkalis

This method is particularly applicable to the more reactive benzyl halides which are easily hydrolyzed in the aqueous media usually employed for the metathetical reaction with alkali cyanides. For example, anisyl chloride treated with sodium cyanide in aqueous dioxane gives, as a by-product, 5-10% of anisyl alcohol as determined by infrared analysis. The use of anhydrous acetone not only prevents hydrolysis to the alcohol but also decreases the formation of isonitriles. This method was also applied successfully by the submitters to the preparation of -chlo-rophenylacetonitrile in 74% yield. 

Iron halides react with halide salts to afford anionic halide complexes. Because iron(III) is a hard acid, the complexes that it forms are most stable with F and decrease in both coordination number and stability with heavier halides. No stable I complexes are known. [FeF5(H20)]2 is the predominant iron fluoride species in aqueous solution. The [FeF6]3 ion can be prepared in fused salts. Whereas six-coordinate [FeClJ3 is known, four-coordinate complexes are favored for chloride. Salts of tetrahedral [FeClJ can be isolated if large cations such as tetraphenylarsonium or tetraalkylammonium are used. [FeBrJ is known but is thermally unstable and disproportionates to iron(II) and bromine. Complex anions of iron(II) halides are less common. [FeClJ2 has been obtained from FeCl2 by reaction with alkali metal chlorides in the melt or with tetraethylammonium chloride in deoxygenated ethanol. 

Tolylsulfonylmethylnitrosamide is a useful substance for the preparation of diazomethane.2 It is apparently of low toxicity. An explosive decomposition has never been encountered by the submitters during its preparation, recrystallization, storage, or the reaction with alkali to form diazomethane. These properties afford advantages over other nitroso compounds which have been used for preparation of diazomethanc. 

Sulphonic Acids to Hydroxyl Compounds.—(4) Reactions with alkalies by fusion. In the aliphatic series the most important synthetic reaction for the formation of hydroxyl derivatives is the treatment of the alkyl halides with silver hydroxide, which reaction we have said does not occur in the benzene series when the substitution is in the ring and not in the side chain. The most important method for preparing ring-hydroxyl compounds is by the fusion of a sulphonic acid or its salt with alkalies, potassium or sodium hydroxide, a reaction which does not occur with the aliphatic sulphonic acids. 

The preparation of adducts of conjugated hydrocarbons, especially aromatic hydrocarbons, by reaction with alkali metals, M ... 

The preparation of adducts of conjugated hydrocarbons by reaction with alkali metals demands absence of Oj, HjO or solvent impurities that can combine with the organometallic product or the alkali metal. The T must be below the decomposition point of the organoalkali compound in the particular solvent. Adequate contact between the alkali metal and the hydrocarbon must be established. In small-scale preparations the alkali metal is deposited as a mirror on the walls of the reaction vessel, where it can come in contact with solvent. In larger scale or synthetic preparations the alkali metal is in the form of a sand or dispersion (see 5.5.3.2.1), and good stirring may be helpful. 

In the most favorable preparative method for the synthesis of nitriles (482 equation 222) alkoxymethyleneiminium salts serve as starting materials, their reaction with alkali metal cyanides in a two-phase system (water/benzene or water/cyclohexane) affords the desired compounds in good yields. An analogous reaction has been performed in acetonitrile. ... 

In solution, all six possible fulleride anions can be prepared and have been studied by various methods. The results are summarized in the review by Reed and Bolskar [18]. The most common reduction methods are the reaction with alkali metals or electrochemistry. In these cases, marked solvent dependence is observed indicating that the effect of the environment is not negligible even in dilute solutions. 

Although so far utilized (64a) only for the preparation of aryloxide derivatives, ether adducts of the lanthanide nitrates, such as [Ln(N03)3-Me0(CH2CH20)4Me], may also prove to be convenient starting materials for their alkoxide analogues by reactions with alkali alkoxides. 

We have carried out the procedure for 1-methylcyclopropene several times with freshly prepared sodamide (see Chap. I, Exp. 7). In most cases the ratio of 1-methylcyclopropene to methylenecyclopropane was greater than 3, in one experiment even 10. The original paper reports the formation of almost pure 1-methylcyclopropene. The authors used commercial sodamide, which might be less reactive than the freshly prepared base, and therefore unable to cause isomerization. Since the protons in methylenecyclopropane are less acidic than the vinylic proton in 1-methylcyclopropene, the exocyclic isomer is not likely to interfere in metallation reactions with alkali amides in liquid ammonia or with LD A... 

The procedure is employed for two purposes. It separates straight-chain acids from branched-chain or cyclic compounds with the former normally concentrating in the adduct and the latter normally in the mother liquor. It has thus been used to concentrate branched-chain and cyclic acids in natural mixtures particularly when these are present only as trace constituents and to isolate cyclic acids prepared from polyene acids. One report, for example, describes the isolation of cyclic acids produced from linseed oil by high-temperature reaction with alkali in 90-95% yield and 95% purity. Urea fractionation is also used to separate adds or esters of differing unsaturation and is an important step in the isolation of pure oleic, linoleic, and linolenic acids from natural sources (Section 4.7). For example, the mixed fatty acids of cod liver oil containing 21% of n — 3 adds (mainly 18 4, 20 5 and 22 6) form an 85% concentrate of these adds (in 25% yield) after a single treatment with urea. 

The detailed structure of the clathrate compound formed between 2,5,5-trimethylhex-3-yn-2-ol and 4-p hydroxyphenyl-2,2,4-trimethylthio> chroman has been determined by A -ray crystallography. tra/i5 -3,4-Dibromothiochroman and analogous dibromo-naphthothio-pyrans, prepared by addition of bromine to the appropriate A -thio-chromenes, may exist in sofa conformations. The dibromo-compounds undergo ring-contraction reactions with alkalis, yielding benzo[ ]thiophen derivatives. ... 

MABs, such as LiAB and NaAB, can be prepared by reactions of AB with metal hydrides in solution, as given by Equation 16.47. The synthesis of other MABs has been accomplished by exchange reactions with alkali metal MABs, as in the example given by Equation 16.48 [135]. Syntheses of MABs by high-energy ball milling of AB with alkali metal hydrides have also been reported [137]. 

The lactam anion in the form of lactam salt (lactamate) can be obtained by in situ reaction with alkali metal compounds, or prepared ex situ and then introduced in the polymerization mixture. Some confusion may arise about the terms often used in the literature to identify the various compounds mentioned in previous sections (initiators, or catalysts, or precursors). In this chapter, we prefer to consider the lactamate as the tme initiator and the alkali metal compound as the precursor. A great niunber of precursors are able to generate... 

Metallic Antimonides. Numerous binary compounds of antimony with metallic elements are known. The most important of these are indium antimonide [1312-41 -0] InSb, gallium antimonide [12064-03-8] GaSb, and aluminum antimonide [25152-52-7] AlSb, which find extensive use as semiconductors. The alkali metal antimonides, such as lithium antimonide [12057-30-6] and sodium antimonide [12058-86-5] do not consist of simple ions. Rather, there is appreciable covalent bonding between the alkali metal and the Sb as well as between pairs of Na atoms. These compounds are useful for the preparation of organoantimony compounds, such as trimethylstibine [594-10-5] (CH2)2Sb, by reaction with an organohalogen compound. 

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