Ethylene bromide anhydrous

SYNTHESIS To a solution of 50 g 3,4-dihydroxy-5-methoxybenzaldehyde in 100 mL distilled acetone there was added 70 g ethylene bromide and 58 g finely powdered anhydrous KjCOj. The mixture was held at reflux for 5 days. This was then poured into 1.5 L H20 and extracted with 4x 100 mL CH,C12. Removal of the solvent from the pooled extracts gave a residue which was distilled at 19 mm/Hg. Several of the fractions taken in the 203-210 °C range spontaneously crystallized, and they were pooled to give 18.3 g of 3-methoxy-4,5-ethylenedioxybenzaldehyde as white solids with a mp of 80-81 °C. A small sample with an equal weight of malononitrile in EtOH treated with a few drops of triethylamine gave 3-methoxy-4,5-ethylenedioxybenzalmalononitrile as pale yellow crystals from EtOH with a mp of 153-154 °C. 

Methoxyhexylmagnesium chloride, obtained from l-chloro-5-methoxyhexane and Mg in anhydrous ether with ethylene bromide and ethyl bromide as initial activators, treated at reflux with anhydrous gaseous formaldehyde prepared by heating a soln. of hydroxymethoxycyclohexane 6-methoxyheptanol. Y 78%. F. e. s. G. Michel and S. Tchelitcheff, Bl. 196A, 2230 ethylene bromide as entrainer s. D. E. Pearson and D. Gowan, Org. Synth. 44, 78 (1964). 

Solvents that have been used with thiocyanogen include benzene, bromobenzene, carbon tetrachloride, chloroform, ether, ethylene bromide, carbon disulfide, petroleum ether, methyl acetate, nitromethane, and anhydrous formic and acetic acids. At low temperatures such solvents as saturated solutions of alkali thiocyanates in methanol or acetone can be used. The yield in the thiocyanation of amines is 20-30% higher when the reaction is carried out in a neutral medium like methanol rather than in acetic acid. The formation of a thiazole is also inhibited in a neutral solvent. Ether is usually not satisfactory because the solvent is attacked and because some of the amine is precipitated as the thiocyanate. On the other hand, thiocyanation of phenols appears to give better yields in acetic acid solution than in neutral solvents. 

Dry tetrahydrofuran and acetic anhyride added to a stirred ice-cooled suspension of anhydrous MgBrg (prepared from Mg-turnings and ethylene bromide in ether under argon) in acetonitrile, brought to room temp., and stirred 12 hrs. -> 4-bromobutyl acetate. Y 96.5%. F. e. s. D. J. Goldsmith, E. Kennedy, and R. G. Campbell, J. Org. Chem. 40, 3571 (1975). 

Alkyl fluorides may be prepared in moderate yield by interaction of an alkyl bromide with anhydrous potassium fluoride in the presence of dry ethylene glycol as a solvent for the inorganic fluoride, for example ... 

Alkyl fluorides have been prepared by reaction between elementary fluorine and the paraffins, by the addition of hydrogen fluoride to olefins, by the reaction of alkyl halides with mercurous fluoride, with mercuric fluoride, with silver fluoride, or with potassium fluoride under pressure. The procedure used is based on that of Hoffmann involving interaction at atmospheric pressure of anhydrous potassium fluoride with an alkyl halide in the presence of ethylene glycol as a solvent for the inorganic fluoride a small amount of olefin accompanies the alkyl fluoride produced and is readily removed by treatment with bromine-potassium bromide solution. Methods for the preparation of alkyl monofluorides have been reviewed. ... 

To a well stirred suspension of 9 g of sodium phenyl acetate and 2.4 g of magnesium turnings in 25 cc of anhydrous ether, a solution of 9.4 cc of isopropyl bromide in 50 cc of anhydrous ether are added. The mixture is refluxed for one hour (during which time propane is evolved) and then 5 cc of cyclopentanone in 25 cc of anhydrous ether are added dropwise. The mixture is then refluxed for one hour and poured over ice water containing some hydrochloric acid. The ether solution is separated and extracted with 200 cc of 5% sodium hydroxide. The alkaline solution on acidification gives the free acid which is filtered off, dried in a desiccator and recrystallized from a mixture of ethylene dichloride and petroleum ether. 

In a 3-1. round-bottomed flask fitted with a mechanical stirrer and a reflux condenser is placed 2.0 1. of anhydrous ethanol. To this is added 11.5 g. (0.5 g.-atom) of sodium cut into small pieces. When the sodium is completely dissolved, 23.6 g. (21.0 ml., 0.25 mole) of 1,2-ethanedithiol2 is added, followed by 47.0 g. (21.7 ml., 0.25 mole) of ethylene dibromide. The mixture is stirred and refluxed for 4 hours, cooled, and filtered to remove some sodium bromide mixed with polyethylene sulfide. The solid is washed with 100 ml. of ethanol, and the combined filtrates are distilled with stirring. When bumping becomes troublesome, as it generally does when 1.3-1.5 1. of distillate has been collected, the hot reaction mixture is filtered to remove sodium bromide, and the sodium bromide is washed with 100 ml. of hot ethanol. 

From ethylene and hydrogen bromide at —78° in the presence of anhydrous aluminum bromide. Tulleners, Tuyn, and Waterman, Rec. trav. chim. 53, 549 (1934). 

Dibromobibenzyl has been prepared by the bromination of bibenzyl in water 9 by the reaction of />-bromobenzyl bromide with zinc dust in water 10 and by the reaction of bromobenzene with ethylene oxide in the presence of anhydrous aluminum chloride.11... 

Ethyl acetoacetate, 20, 26 21, 23, 46,67 Ethyl acrylate, 20, 36 Ethyl alcohol, anhydrous, 22, 59 Ethyl benzoate, 20, 32 Ethyl bromide, 22, 59 Ethyl bromoacetate, 21, 51 Ethyl a-bromoisobutyrate, 21, 53 Ethyl /3-bromopropionate, 20, 6S Ethyl caprylate, 20, 69 Ethyl chlorocarbonate, 21, 81 2-Ethylchromone, 21, 42 Ethyl diacetylacetate, 21, 46 COPPER DERIVATIVE, 21, 45 Ethyl a,a-DIMETHYL-/3-PHENYL-/3-HY-DROXYPROPIONATE, 21, S3 Ethylene chloride, 20, 28 22, 76 Ethyl 1,16-hexadecanedicarboxy-late, 21, 48... 

The transformation of alkyl halides into alkanenitriles with cyanide ions has frequently been carried out in protic solvents such as methanol or ethanol, sometimes with the addition of water or acetone, and often at elevated temperatures. Under these conditions reaction rates decrease in the order iodides, bromides, chlorides, as would be expected. Accordingly iodide ions have a catalytic effect and increase reaction rates. The use of anhydrous ethylene glycol or di- and poly-ethylene glycols and their corresponding ethers allows the use of higher temperatures, which means better solubility of the alkali metal cyanides. There is probably additional help from the extensive solvation of the countercations by some of these hydroxy polyethers. While for primary halides yields for nitriles range up to 90% (Table 1), they drop sharply with secondary and tertiary halides. ... 

Alkyl fluorides. For the preparation of n-hexyl fluoride, a round-bottomed flask equipped with a stirrer, a dropping tube, and a short fractionating column is charged with 2 moles of anhydrous, flnely ground potassium fluoride and 200 g. of ethylene glycol, heated in an oil bath at 160-170°, and 1 mole of n-hexyl bromide is added... 

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