Magnesium bromide Ether preparation

The manufacture of the cyclohexyl analog is as follows. Phenyl magnesium bromide was prepared from 48.5 g (0.308 mol) of bromobenzene, 7 g (0,29 mol) of magnesium, and 125 ml of dry ether. To it was added at 5°C over a period of A hour 40 g (0.18 mol) of cyclohexyl (3-(N-piperidyl)-ethyl ketone (BP 115° to 117°C/1 mm) in 125 ml of dry ether. The mixture was allowed slowly to come to room temperature, refluxed for one hour, and then poured into ice containing 80 ml of concentrated hydrochloric acid. Ammonium chloride (100 g) and 200 ml of concentrated ammonium hydroxide were added and the organic layer was separated. After drying and removing the solvent, the residue was distilled under reduced pressure. The base distilled at 158° to 170°C (1 mm) and solidified. Upon recrystallization from methanol it melted at 112° to 113°C. 

Preparation of 3-Hexyne-2-ol A solution of ethyl magnesium bromide was prepared by the reaction of 229 g of ethyl bromide and 4B.6 g of magnesium in 750 ml of anhydrous ether. To the ether solution was then added with stirring a solution of 10B g of ethyl acetylene in 250 ml of cold anhydrous ether. The addition required approximately 3 hours, and the mixture was stirred and refluxed for a further period of 3V2 hours. Thereafter there was added to the reaction mixture a solution of BB g of freshly distilled acetaldehyde in 170 ml of anhydrous ether, over a period of about 45 minutes and at a temperature in the range of about -10° to 0°C. 

Cyclopentanecarboxaldehyde has been prepared by the procedure described above 2 3 by the reaction of aqueous nitric acid and mercuric nitrate with cyclohexene 6 by the action of magnesium bromide etherate 6 or thoria 7 on cyclohexene oxide by the dehydration of frarei-l, 2-cyclohexanediol over alumina mixed with glass helices 8 by the dehydration of divinyl glycol over alumina followed by reduction 9 by the reaction of cyclopentene with a solution of [HFe(CO)4] under a carbon monoxide atmosphere 10 and by the reaction of cyclopentadiene with dicobalt octacarbonyl under a hydrogen and carbon monoxide atmosphere.11... 

An ethereal solution of phenyl magnesium bromide is prepared 1 Blaise, Compt. rend., 1901, 133, 1217. 

Trifluoromethyl)-2-(2-chloro)ethoxy-l-bromoethane (3-Trifluoromethyl)phenyl magnesium bromide is prepared under the normal conditions for magnesium derivatives, from 48.6 g of magnesium turnings and 455.7 g of (3-trifluoromethyl)bromobenzeneand 1.5 liters anhydrous ether. 

Methoxyphenyl Phenyl Tellurium (Grignard Method) Phenyl magnesium bromide is prepared from 0.84 g (35 mmol) of magnesium and 5.5 g (35 mmol) of bromobenzene in 15 m/ of absolute diethyl ether under nitrogen and the resultant solution is cooled in an ice/watcr bath. 4.7 g (10 mmol) of bis [4-methoxyphenyl] ditellurium dissolved in 100 ml of absolute diethyl ether are added dropwise to the Grignard solution. Then 250 ml of petroleum ether (b.p. 30- 50°) are added to precipitate the tellurolate and the mixture is allowed to stand for 2 h. The precipitate is filtered off, the filtrate is mixed with aqueous ammonium chloride solution, the organic phase is separated, dried with sodium sulfate, and the solvent is evaporated. Methanol is added to the oily residue to crystallize the product yield 3.1 g (100%) m.p. 61° (from methanol). 

Isomerization, see also NaphthaIene-2,6-dicarboxylic acid, preparation Aldqximes — Amides Nickel acetate tetrahydrate. Dienes Phenylpotassium. Epoxides Lithium diethylamide. Magnesium bromide etherate. Nonconjuoateo enones p-Tolu iesulfonic acid. Olefins (cis-trans)-. Iodine. Selenium. Olefins (bond migration) N-Lithioethylenediamine. Lithium diethylamide. Potassium l-butoxide. Sodium tetrafluoroboric s d. Thioglycolic acid. Polyenes Sulfur dioxide. 

Butylmagnesium bromide, for example, is prepared by treating 1-bromobutane in diethyl ether with magnesium metal. Aryl Grignard reagents, such as phenyl-magnesium bromide, are prepared in the same manner. These reactions are referred to as oxidative additions because they result in an increase in the formal oxidation state of magnesium by two [i.e., from Mg(0) to Mg(II)]. 

Add 4 0 g. (4 0 ml.) of pure anihne dropwise to a cold solution of ethyl magnesium bromide (or iodide) prepared from 1 Og. of magnesium, 5 0 g. (3-5 ml.) of ethyl bromide (or the equivalent quantity of ethyl iodide), and 30 ml. of pure, sodium-dried ether. When the vigorous evolution of ethane has ceased, introduce 0 02 mol of the ester in 10 ml. of anhydrous ether, and warm the mixture on a water bath for 10 minutes cool. Add dilute hydrochloric acid to dissolve the magnesium compounds and excess of aniline. Separate the ethereal layer, dry it with anhydrous magnesium sulphate and evaporate the ether. Recrystallise the residual anihde, which is obtained in almost quantitative yield, from dilute alcohol or other suitable solvent. 

To a mixture of 0.10 mol of 1-ethoxy-l,2-heptadiene (see this chapter, Exp. 13) and 120 ml of diethyl ether was added 1 g of copper(I) bromide. A solution of butyl magnesium bromide in about 200 ml of diethyl ether, prepared from 0.25 mol of butyl bromide (see Chapter II, Exp. 5) was added in 15 min. The reaction was weakly exothermic and the temperature rose slowly to about 32°C. The mixture was held for an additional 40 min at that temperature, then the black reaction mixture was... 

A 20% excess of ethylmagnesium bromide was prepared from magnesium (6.5 g) in ether (80 ml) by adding ethyl bromide (30 g) in ether (30 ml). Indole (25.8 g) in benzene (50 ml) was then added slowly with stirring and stirring was continued for 20 min after addition was complete. A solution of allyl bromide (29.2 g) in benzene (20 ml) was then added slowly. The mixture was stirred overnight and then diluted with ether and the product isolated and purified by distillation (22.7 g, 70% yield). 

For example, dithioben2oic acid [121 -68-6] results from the reaction of carbon disulfide, phenyl bromide, ether, and magnesium. Sodium a2idodithiocarbonate [38093-88-8] is prepared by the reaction of aqueous sodium a2ide [26628-22-8] at 40—50°C ... 

A 3-I. three-necked, round-bottom flask is fitted with a mechanical stirrer through a mercury seal, a reflux condenser and a i-l. separatory funnel. A mixture of 200 g. (r mole) of 2,3-dibromopropene (Org. Syn. 5, 49) and 200 cc. of dry ether is added. The flask is now cooled in an ice bath, the stirrer is started, and one molecular equivalent of cyclohexylmagnesium bromide, prepared from 31 g. of magnesium, 204 g. of cyclohexyl bromide and 400 cc. of dry ether (Note i) is added at such a rate that the mixture refluxes gently (Note 2). The addition takes about one-half to three-quarters of an hour. Two layers are formed and magnesium bromide may or may not separate. 

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