W Butyl bromide

The method described here has been adapted from the directions of Gilman and Heck,2 and Rossander and Marvel.3 w-Amyl benzene has also been prepared by the action of sodium on a mixture of benzyl and w-butyl bromides,4 and by heating w-butyl phenyl ketone and formic acid with copper at 3000.5... 

In a 1-1. three-necked flask equipped with a dry ice-acctone condenser and a sealed mechanical stirrer is placed 700 ml. of commercial, anhydrous, liquid ammonia. To the stirred ammonia is added a small piece of potassium metal. (Caution1 Care should he exercised in handling potassium metal, since it is extremely reactive and it ignites on contact with water, atmospheric moisture, or alcohol. It should he manipulated under toluene or xylene, and blotted with filter paper before addition.) After the appearance of a blue color a few crystals of ferric nitrate hydrate (ca. 0.1 g.) are added, followed by small pieces of freshly cut potassium metal until 7.0 g. (0.18 g. atom) has been added. After all the potassium has been converted to the amide (Note 7), 24.9 g. (0.154 mole) of sodio-2-formyl-6-methylcyclohexanone is added carefully through a powder funnel (Note 8). After 1 hour a solution of 28.2 g. (0.21 mole) of w-butyl bromide (Note 9) in 50 ml. of anhydrous ether is added dropwise from an addition funnel. The mixture is stirred for 3 hours, and then the dry ice-acetone condenser is replaced by a water condenser. A steam bath is placed under the flask, and the ammonia is evaporated (Caution ) as 400 ml. of anhydrous ether is added. When the... 

Eastman Organic Chemicals Eastman grade w-butyl bromide was distilled b.p. 101-102°. 

Laboratory reagent grade w-butyl bromide (greater than 98% pure) was used after drying over molecular sieves. 

Treatment of sodium and potassium nitronates with alkyl halides typically results in the formation of oximes and carbonyl compounds by cleavage of the N—O bond (11). In one case, however, reaction of w-butyl bromide with the potassium salt of nitro ester 191 does afford the -butyl nitronate (192, Eq. 2.14) (154). 

The fact that n- butyl benzene call be prepared in reasonable yield by the action of sodium upon a mixture of bromobenzene and w-butyl bromide can be partly explained on the assumption that n- butyl bromide reacts with phenyl-sodium more rapidly than does bromobeuzene. It is interesting to note that n-butylbenzene can be prepared either from benzylsodium and w-propyl bromide or from phenylsodium and n-butyl bromide (Section VI,29). 

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. 

A dry, 3-1., three-necked, round-bottomed flask (Notes 1 and 2) is fitted with an efficient reflux condenser (Note 3) protected by a drying tube, a dropping funnel, and a thermometer which extends well into the reaction mixture (Note 4) the flask is arranged so that it can be cooled externally (Note 5). In the flask is placed 161 g. (7 gram atoms) of sodium cut into shavings 1-2 mm. in thickness (Notes 6 and 7) the sodium is just covered with dry ether (about 300 ml.) (Note 8). A mixture of 411 g. (321 ml., 3 moles) of w-butyl bromide and 471 g. (315 ml., 3 moles) of bromobenzene (Note 9) is added slowly from the dropping funnel over a period of about 2.5 hours, the temperature being kept as near 20° as possible the mass acquires a bluish color. 

Ethyl M-butylacetoacetate has always been prepared by the action of w-butyl bromide on the sodium salt of ethyl acetoacet-ate.1 The procedure given above is the usual one for alkylating ethyl acetoacetate. 

Redistilled w-butyl bromide boiling over a i-degree range should be used. 

Reaction XXXVUI. (a) Action of Aqueous and Alcoholic Potassium or Sodium Cyanide on Aliphatic Halogen Compounds, and Hydrolysis of the Nitriles so formed. (B., 14, 1965 15, 2318.)—The preparation and hydrolysis of nitriles are dealt with on p. 151 and p. 239 respectively. In many cases, however, it is unnecessary to isolate the nitrile it can be directly hydrolysed to the corresponding acid on its formation. Among others, the following syntheses have been carried out in this way — i (i.) w-Valeric acid [jpentan acid] from w-butyl bromide (Am. Soc., 42, 310). 

B. 3-Methylkeptanoic acid. In a 2-1. three-necked flask fitted with a mercury-sealed stirrer, a reflux condenser carrying a calcium chloride tube, and a dropping funnel are placed 25.0 g. (1.04 g. atoms) of magnesium turnings. The flask is heated to about 100° for a few minutes and then cooled to room temperature. A solution of 178 g. (1.30 moles) of w-butyl bromide in 300 ml. of dry ether is prepared and of this solution about 10 ml., together with 30 ml. of dry ether, is run into the flask. The reaction is started by heating to reflux for a few seconds, the stirrer is started, and the remainder of the bromide solution is added at such a rate as to maintain constant reflux (about 1 hour). 

The w-butyl bromide (Org. Syn. 1, 5) boiled over a range of three degrees. The excess was used in order to decrease the time necessary to complete the reaction. 

Dibromopropane 1-Bromobutane (w-Butyl bromide) 1-Bromopentane ( -Amyl bromide) 1-Bromohexane 1-Bromoheptane 1-Bromooctane 1-Bromodecane... 

The method described is successfully used for the alkylation and aralkylation of ethyl and /-butyl phenylacetate.3 The alkylation of ethyl phenylacetate with methyl iodide, M-butyl bromide, benzyl chloride, and a-phenylethyl chloride affords the corresponding pure monoalkylation products in 69%, 91%, 85%, and 70% (erythro isomer) yields, respectively. The alkylation of /-butyl phenylacetate with methyl iodide, w-butyl bromide, a-phenylethyl chloride, and /3-phenylethyl bromide gives the corresponding pure monoalkylated products in 83%, 86%, 72-73%, and 76% yields, respectively. 

Certain of the monoalkylated ethyl phenylacetates have been further alkylated with alkyl and aralkyl halides to produce the corresponding disubstituted phenylacetic esters.8 Ethyl 2-phenyl-propanoate has been alkylated by methyl iodide to give pure ethyl 2-methyl-2-phenylpropanoate in 81% yield. Similarly, the alkylations of ethyl 2-phenylhexanoate with methyl iodide, w-butyl bromide, and benzyl chloride gave the corresponding pure dialkylated products in 73%, 92%, and 72% yields, respectively. 

The use of a modified sodium bromide-sulfuric acid method for the preparation of alkyl bromides is described in connection with the preparation of w-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 reaction of ammonia with primary alkyl halides generally forms a mixture of primary, secondary, and tertiary amines and even a certain amount of the quaternary ammonium halide. Still, the method may be profitable for obtaining primary amines if the halogen compound is above C, and excess ammonia is employed, for then polyalkylation is less likely and the products, having widely different boiling points, are more readily separated. Thus w-butyl bromide and a large excess of ammonia in alcohol solution at room temperature give a 47% yield of w-butylamine. ... 

A 10% excess of sodium amide and w-butyl bromide with respect to diphenylmethane was adopted. 

This procedure for the acetylation of methyl alkyl ketones to form j8-diketones is a modification of an earlier procedure, which used boron trifluoride gas as the catalyst. 3-w-Butyl-2,4-pentanedione has also been prepared by the acetylation of 2-heptanone catalyzed with boron trifluoride gas, by the thermal rearrangement of the enol acetate of 2-heptanone, and by the alkylation of the potassium enolate of 2,4-pentanedione with w-butyl bromide. ... 

Problem 3.22 The final step in the proof of structure of an unknown alkane was its synthesis by the coupling of lithium di(rer/-butyl)copper w ith w-butyl bromide. What was the alkane ... 

Write equations for the most likely side reactions in the conversion of w-butyl bromide into ... 

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