Process for the Extraction of the Hydroxylated Ethers of Phenol from Mixtures.
Year: 1897

page_text: Date of Application, 25th May, 1897-Accepted 17th July, 1897
COMPLETE SPECIFICATION.
Process for the Extraction of the Hydroxylated Ethers of Phenol
from Mixtures.
I, LEONHARD LEDERER of 76, Gabelsbergerstrasse, Munich in the Empire of
Germany, Doctor of Science, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascertained
in and by the following statement:-
It is well-known that phenol combines with fixed alkalies in the cold to form saline
compounds which greedily absorb carbonic acid and thereby become decomposed,
whilst the alkaline carbonates according to Runge's statements, are not decomposed,
even with heat. In contrary to this, Baumann maintains (Proceedings of the German
Chemical Society, Vol. X. pages 686-687) that phenol, when boiled for a prolonged
period with a solution of potassium carbonate gives off carbonic acid, and that also
other phenols seen to behave in the same manner, without however giving any
explanation of this last statement.
I have observed that the hydroxylated ethers of phenols, however similar their
properties may be to those of phenol, seem to have a behaviour which is quite
peculiar or specific with respect to potassium carbonate. They have amongst others
the property of forming crystalline compounds with potassium carbonate which
property is wholly wanting in phenol and its homologues. The compounds of
potassium carbonate with the acid ethers of phenol are permanent in the air; they
are partly decomposed by water; the presence of potassium carbonate prevents their
decomposition. They are soluble in alcohol and in benzine by heat when they are
added gradually. In the cold they are precipitated again in the form of crystals.
Their composition may be expressed by the formula R,K,CO,, in which R designates
a hydroxylated ether of phenol. The exceptional manner in which these hydroxylated
ethers of phenol behave in the presence of potassium carbonate may be utilised with
very great advantage for extracting the same from mixtures containing phenol-in.
this manner guajacol, creosol, ethyl-guajacol, pyrogallic ether can be extracted from
wood-tar-oils and many other substances such for example, as the turpenes in oil of
cloves.
As will be clearly understood from the preceding, the new process has no relation
with the observation of Baumann's above cited, nor with the process for the separation
of creosol and of phlorol described by Tiemann & Mendelsohn (Reports of the German
Chemical Society, Vol. X. page 57).
DESCRIPTION.
I. One part of liquid guajacol is mixed with one part of potassium carbonate with
an addition of a small quantity of water. According to the amount of guajacol, there
is formed immediately, or after a short time, a crystalline mass saturated with oil
to which when the reaction is finished there is added ether, ligroine or other similar
solvents, and which is separated from the lye by aspiration or by compression. The
guajacol is separated from the double compound by decomposition by means of
carbonic acid or dilute acids, and is freed from small quantities of resinous products

page_text: by distilling in a current of steam. The preparation thus produced is absolutely
pure. It crystallises spontaneously on the introduction of a crystal of guajacol into
the product which has been distilled in steam, without-it being necessary to use
any further means of cooling.
II. One part of creosote and two parts of a concentrated solution of potash are 5
mixed by shaking up together for some time. The mixture is then allowed to settle;
the aqueous portion is separated from the oil, and the residue is mixed with ether by
which the compounds of potassium carbonate are precipitated in the form of crystals.
After removal of the lye the residue is decomposed as stated in I, and is purified. In
this manner there is produced a compound which is quite free from valueless
phenols.
III. One part of oil of cloves and one part of potassium carbonate are carefully
mixed together for some time with the addition of a small quantity of water. To
the mixture resulting from the reaction there is then added ether, and the lye is
removed in the usual manner, and the crystalline residue is treated as above 1
described.
IV. The mixture methyl-hydroquinone and of dimethyl-hydroquinone which is
produced according to Hesse (Liebig's Annalen der Chemie Vol. 200 page 254) by
heating hydroquinone with methyliodine and hydroxide of potash, is shaken up for a
certain period with a concentrated solution of carbonate of potassium. After removal
of the aqueous portion, the residue is treated with a mixture of benzol and
petroleum-ether. The separated crystalline mass is collected on the filter and is
finally decomposed by dilute acids, whereby methyl-hydroquinone becomes deposited
in the solid state.
Instead of mixing the compounds containing the hydroxylated ethers of phenol 2
with potassium carbonate, they may also be dissolved in potash lye, and froin this
solution the double compounds of potassium carbonate can be extracted by the
introduction of carbonic acid. The final treatment of the product of reaction is
effected in the manner described. Further by prolonged boiling with a solution of
potassium carbonate and then introducing carbonic acid, the hydroxylated ethers 3
of phenol may also be produced in the form of potassium carbonate compounds.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is
Process for the production of hydroxylated ether of phenol from mixtures, a
consisting in bringing mixtures of said substances into reaction with potassium
carbonate as such, in the solid form or in solution, or produced by introducing
carbonic acid into the solution of the potassium salts of the said compounds,
substantially as described.
n day of May 1897.
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M.I. Mech. E.,
Consulting Engineer and Patent Agent,
70, Chancery Lane, London, W.C., Associate Agent.