Trimethylene bromide

Hygric acid was synthesised by Willstatter by the following method. Ethyl bromopropylmalonate, CHaBr. GHj. GHj. GH(G02Et)2, obtained by condensation of trimethylene bromide with ethyl sodio-nmlonate, on bromination yielded ethyl 8-dibromopropylmalonate,... 

N-(2-Ch oroethyl)dimethy amine Trimethylene bromide Ethanol... 

The 7-bromopropylphthalimide was prepared from potassium phthalimide and trimethylene bromide in 78% yields, using the conditions and molar quantities specified for the preparation of (3-bromoethylphthalimide.1 7-Bromopropylphthalimide can also be prepared from phthalimide, potassium carbonate, and trimethylene bromide.2... 

Cyclobutanedicarboxylic acid has been prepared by hydrolysis of the ethyl ester,1 or of the half nitrile, 1-cyano-l-car-boxycyclobutane.2 The ethyl ester has been prepared by condensation of ethyl malonate with trimethylene bromide1 or chloro-bromide.3 The half nitrile has been prepared by condensation of trimethylene bromide with ethyl cyanoacetate followed by hydrolysis of the ester to the acid.2... 

Trimethylene bromide... Hexamethylene bromide. Nonamethylene bromide... 

Just a year before E. Fischer obtained this compound by the hydrolysis of caseinogen, it was synthesised by Willstatter in 1900 from sodium malonic ester and trimethylene bromide by the following reactions —... 

Sorensen and Andersen in 1908 synthesised proline by the sodium phthalimidomalonic ester method, a yield of about 80 per cent, being obtained. Sodium phthalimidomalonic ester is condensed with trimethylene bromide,... 

The use of a modified sodium bromide-sulfuric acid method for the preparation of alkyl bromides is described in connection with the preparation of ra-butyl bromide. This method has been used also for the preparations of iso-amyl and trimethylene bromides, but, in general, the yields were found to be somewhat lower than those obtained with the hydrobromic-sulfuric acid method. 

The trimethylene bromide is purified as directed under w-Butyl Bromide. A yield of 1088 g. boiling at 162-165° (90 per cent theory) is obtained. In a number of experiments, the lowest yield obtained was 88 per cent, whereas the maximum obtained was 95 per cent. 

Sodium Bromide Method. The yields of trimethylene bromide by the sodium bromide method as described under w-Butyl Bromide are slightly lower than those given above. Thus, from I3S° S- °f water, 1545 g. of sodium bromide, 456 g. of trimethylene glycol, and 2500 g. of sulfuric acid, a yield of mo g. of crude product is obtained, from which, after purification and distillation, a yield of 1030 g. of bromide (85 per cent theory) is obtained. 

Trimethylene bromide prepared by direct distillation of the reaction mixture without the preliminary refluxing period contains appreciable amounts of trimethylene bromohydrin. In the purification of trimethylene bromide with sulfuric acid the high specific gravity of the former (1.987) must be borne in mind. Vigorous shaking with sulfuric acid may result in the formation of emulsions. 

The methods for making allyl alcohol are many. It may be prepared by (a) the action of metals upon dichlorohydrin 1 (b) the reduction of acrolein 2 (c) the action of potassium hydroxide on trimethylene bromide 3 (d) the catalytic decomposition of glycerol with aluminum oxide 4 (e) the hydrolysis of allyl iodide 5 (/) the decomposition of glycerol triformate 6 (g) the action of formic acid upon glycerin 7 and (h) the action of... 

Pimelic acid has been prepared as a by-product of the reaction between trimethylene bromide and sodium cyanoacetic ester 1 by the action of carbon dioxide upon pcntamethylene-... 

In a 5-I. round-bottom flask fitted with a stopper holding a reflux condenser and a separatory funnel, are placed 294 g. (6 moles) of sodium cyanide and 300 cc. of water. The flask is heated on a steam bath until most of the sodium cyanide is in solution. This requires two to three hours. A solution of 500 g. (2.47 moles) of trimethylene bromide (Note 1) in 11. of 95 per cent alcohol is then added through the separatory funnel over a period of forty to sixty minutes. The mixture is refluxed for thirty to forty hours (Note 2) on a steam bath. Then the solvent is removed, preferably under reduced pressure. The residue, consisting of sodium bromide, sodium cyanide, and trimethylene cyanide, is extracted with 300-400 cc. of ethyl acetate, which dissolves the trimethylene cyanide and does not dissolve the inorganic salts. This solution is filtered and the salt washed once with about 100 cc. of ethyl acetate. The ethyl acetate is distilled at ordinary pressure (Note 3) and the residual liquid is distilled under reduced pressure. The yield of trimethylene cyanide boiling at i44-i47°/i3 mm. or i3i-i34°/io mm. is 180-200 g. (77-86 per cent of the theoretical amount). 

The only practical method of preparation for trimethylene cyanide is the action of potassium cyanide on trimethylene bromide.1... 

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