Org. Synth. 1926, 6, 54
Submitted by E. E. Dreger
Checked by Roger Adams and G. S. Hiers.
In a 5-l. round-bottomed flask
, fitted with a stirrer
, separatory funnel
, and a reflux condenser
to the upper end of which a calcium chloride tube
is attached, is placed 150 g. (6.2 atoms) of magnesium turnings
. A small crystal of iodine (Note 1)
and about 100 cc. of a mixture of 822 g. (6 moles) of n-butyl bromide (p. 28) and 2 l. of anhydrous ethyl ether
are added. As soon as the reaction starts, 350 cc. of anhydrous ether
is added, and the remainder of the n-butyl bromide
solution is dropped in at such a rate that the mixture boils continuously. The time of addition (one and one-half hours) may be decreased by cooling the flask externally. Stirring is started as soon as enough liquid is present in the flask.
When all has been added (Note 2), 278 g. (6.3 moles) of ethylene oxide (Note 3) (previously dried with soda lime) is added through a tube (3 or 4 mm. in diameter) the end of which is about 20 mm. above the surface of the liquid (Note 4), the temperature being kept below 10° by cooling in an efficient ice-and-salt bath (Note 5). This addition requires four to six hours. When all has been added the ice bath is removed; the temperature of the mixture generally rises enough to cause gentle boiling. When this ceases the mixture is warmed on a steam bath for one hour longer.
The condenser is then arranged for downward distillation, and when about 1 l. of ether has distilled (Note 6) the receiver is changed and 1 l. of dry benzene (Note 7) is added; distillation is continued with stirring until the temperature of the distilling vapor reaches 65°. The mixture is then boiled under reflux for one hour. Usually by this time it has become so viscous that stirring is no longer efficient. The mixture is then allowed to cool and is decomposed with 2 l. of an ice-water mixture. The precipitated magnesium hydroxide is dissolved by adding a sufficient quantity of 30 per cent sulfuric acid and enough ice to keep the mixture cold.
The mixture of benzene and hexyl alcohol is now distilled in a current of steam; about 7 l. of distillate must be collected before all the product is distilled. The oily layer is separated and the watery portion distilled until free of hexyl alcohol. The oil so obtained is added to the main quantity and the watery portion again distilled. The united product is now stirred on the steam bath for one to two hours with 1 l. of 20 per cent sodium hydroxide solution and again subjected to steam distillation, as before. The oily product so obtained is then distilled under atmospheric pressure with the use of a good fractionating column. The fraction boiling up to 85° is mostly benzene and water. The fraction boiling between 85° and 154° is collected separately for redistillation, and the fraction boiling at 154–157° collected as pure material. There is practically no high-boiling residue. The yield (Note 7) is 368–380 g. (60–62 per cent of the theoretical amount) (Note 8).
The reaction between the ethereal solution of n-butyl bromide
and the magnesium
frequently starts without any assistance, but the presence of a trace of iodine
is of no disadvantage and renders more certain the beginning of the reaction.
The butyl bromide
appears to react as fast as it is added, so that there is no need of stirring or warming the butylmagnesium bromide
solution before adding the ethylene oxide
. The small amount of unattacked magnesium
has no influence on the subsequent reactions.
A convenient arrangement consists of placing the ethylene oxide
tank on suitable scales and noting the proper decrease in weight. The gas may be passed through a short tower filled with soda lime
and then through a spiral condenser surrounded with salt and ice
If the mouth of the delivery tube is beneath the surface, troublesome clogging occurs.
The first reaction appears to consist of the formation of an oxonium addition product of the ethylene oxide and the butylmagnesium bromide
Careful watching is necessary at this point, since if the distillation is carried too far a violent reaction, apparently a rearrangement of the initial addition product, may set in.
By the use of benzene
as a diluent the reaction referred to in (Note 6)
takes place smoothly and without violence; without it the yield is only about 200 g.
Instead of adding the condensed ethylene oxide
, it may be dissolved in 350 cc. of chilled anhydrous ether
which is added during the course of one to two hours. In this case, however, the yields are lower, apparently owing to the vaporization of some of the ethylene oxide
can be prepared by the reduction of ethyl caproate
by sodium and absolute alcohol1
alone or in anhydrous ammonia solution
by the reduction of n-caproamide
and absolute alcohol
by the reduction of n-caproaldehyde
by sodium amalgam in dilute sulfuric acid
by the action of nitrous acid
by the interaction of n-propylmagnesium bromide and trimethylene oxide
being employed as a diluent; and by the procedure described.7
This preparation is referenced from:
Chemical Abstracts Nomenclature (Collective Index Number);
oxonium addition product of the ethylene oxide
sulfuric acid (7664-93-9)
ethyl ether (60-29-7)
sodium hydroxide (1310-73-2)
magnesium turnings (7439-95-4)
n-butyl bromide (109-65-9)
nitrous acid (7782-77-6)
Ethylene oxide (75-21-8)
n-HEXYL ALCOHOL (111-27-3)
Butylmagnesium bromide (693-03-8)
ethyl caproate (123-66-0)
Trimethylene oxide (503-30-0)
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