Magnesium aromatic

Metallic sodium. This metal is employed for the drying of ethers and of saturated and aromatic hydrocarbons. The bulk of the water should first be removed from the liquid or solution by a preliminary drying with anhydrous calcium chloride or magnesium sulphate. Sodium is most effective in the form of fine wire, which is forced directly into the liquid by means of a sodium press (see under Ether, Section II,47,i) a large surface is thus presented to the liquid. It cannot be used for any compound with which it reacts or which is affected by alkalis or is easily subject to reduction (due to the hydrogen evolved during the dehydration), viz., alcohols, acids, esters, organic halides, ketones, aldehydes, and some amines. 

Fast Color Salts. In order to simplify the work of the dyer, diazonium salts, in the form of stable dry powders, were introduced under the name of fast color salts. When dissolved in water they react like ordinary diazo compounds. These diazonium salts, derived from amines, free from solubilizing groups, are prepared by the usual method and are salted out from the solutions as the sulfates, the metallic double salts, or the aromatic sulfonates. The isolated diazonium salt is sold in admixture with anhydrous salts such as sodium sulfate or magnesium sulfate. 

Production of cellulose esters from aromatic acids has not been commercialized because of unfavorable economics. These esters are usually prepared from highly reactive regenerated cellulose, and their physical properties do not differ markedly from cellulose esters prepared from the more readily available aHphatic acids. Benzoate esters have been prepared from regenerated cellulose with benzoyl chloride in pyridine—nitrobenzene (27) or benzene (28). These benzoate esters are soluble in common organic solvents such as acetone or chloroform. Benzoate esters, as well as the nitrochloro-, and methoxy-substituted benzoates, have been prepared from cellulose with the appropriate aromatic acid and chloroacetic anhydride as the impelling agent and magnesium perchlorate as the catalyst (29). 

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. 

Anisole and mixtures of diethyl ether with aromatic hydrocarbons have both been widely employed as solvents for these reactions. Ethers other than diethyl ether and anisole have also been successfully used (cf. refs. 14-17). Hcxamethylphosphorotriamide has recently been used as a solvent for indole Grignard reactions. Young and Mizianty have recently described the use of an aromatic magnesium halide (phenylmagnesium bromide) for the synthesis of indole magnesium bromide. 

Treatment of dihalogeno aromatics with lithium amalgam, magnesium, zinc, etc.,... 

Chiral imines derived from 1-phenylethanone and (I. Sj-exo-l, 7,7-trimethyIbicyclo-[2.2.1]heptan-2-amine [(S)-isobornylamine], (.S>1-phenylethanamine or (R)-l-(1-naphthyl) ethanamine are transformed into the corresponding (vinylamino)dichloroboranes (e.g., 3) by treatment with trichloroborane and triethylamine in dichloromethane. Reaction of the chiral boron azaenolates with aromatic aldehydes at 25 "C, and subsequent acidic hydrolysis, furnishes aldol adducts with enantiomeric excesses in the range of 2.5 to 47.7%. Significantly lower asymmetric inductions are obtained from additions of the corresponding lithium and magnesium azaenolates. Best results arc achieved using (.S )-isobornylamine as the chiral auxiliary 3. 

Such cyclohexadienes are easily oxidizable to benzenes (often by atmospheric oxygen), so this reaction becomes a method of alkylating and arylating suitably substituted (usually hindered) aryl ketones. A similar reaction has been reported for aromatic nitro compounds where 1,3,5-trinitrobenzene reacts with excess methyl-magnesium halide to give 2,4,6-trinitro-l,3,5-trimethylcyclohexane. Both... 

Diols (pinacols) can be synthesized by reduction of aldehydes and ketones with active metals such as sodium, magnesium, or aluminum. Aromatic ketones give better yields than aliphatic ones. The use of a Mg—Mgl2 mixture has been called the Gomberg-Bachmann pinacol synthesis. As with a number of other reactions involving sodium, there is a direct electron transfer here, converting the ketone or aldehyde to a ketyl, which dimerizes. 

Schliiter et al. [161 were the first to describe coupling of aromatic compounds containing aryl-magnesium halide and aryl halide functions, catalyzed by Ni(0) compounds. Here, the authors adapted the principle of attaching solublizing side chains (in the 2- and 5- positions) and arrived at soluble and processable... 

With aliphatic amines, the decomposition catalysis is moderate with heterocyclic aromatic amines (pyridine, quinoline), 0.1 % of amine is sufficient to cause maleic anhydride to decompose. An accident has also been mentioned with NaOH. This decomposition also takes place in the presence of sodium, lithium, ammonium, potassium, calcium, barium, magnesium and beryllium cations. 

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