The Manufacture and Production of Camphorie Ethers of the Pyrocatechinmonoalkylethers.
Year: 1898

page_text: Date of Application, 6th May, 1898
Complete Specification Left, 6th Feb., 1899-Accepted, 6th May, 1899
PROVISIONAL SPECIFICATION.
The Manufacture and Production of Camphorie Ethers of the
Pyrocatechinmonoalkylethers.
I, GEORGE WILLIAM JOHNSON, of 47, Lincoln's Inn Fields, in the County of
London, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by Kalle & Co., of Biebrich-on-the-
Rhine, in the Empire of Germany), to be as follows:-
This invention relates to the preparation of camphoric acid ethers of the pyro-
catechinmonoalkylethers. My foreign correspondents have found that these ethers
are best obtained by heating the two ingredients dissolved in a neutral solvent
together with a condensing agent such as phosphorus oxychloride. Besides vary-
ing quantities of camphoric anhydride the neutral as well as the acid ether is
formed. The two ethers can however be separated by treating the product of the
reaction with alkaline carbonates, which dissolve the acid ether and leave the
neutral ether behind. The neutral ethers are solid crystalline hodies, whilst
the acid ethers are mostly liquids.
This invention may be carried out as follows but the invention is not limited
to the precise details.
EXAMPLE.
A solution of 20 kilos. of camphoric acid and 24'8 kilos. of guajacol in 35 litres
of toluene is kept slowly boiling whilst 17 kilos. of phosphorus oxychloride are
slowly run into the said solution. After boiling the mixture for 15 to 20 hours
the solution is poured off from the resinous matter which is formed during the
reaction, and washed well with dilute sodium carbonate solution. The toluene
solution is then treated with dilute caustic soda lye in order to extract some
unchanged guajacol.
The toluene is now distilled off. The residue contains besides camphoric
diguajacolether some camphoric anhydride. In order to obtain the ether in
a pure state the residue is recrystallized say twice from methyl alcohol.
The pure camphorie diguajacolether, crystallizes in white needles melting at
a temperature of 125-126 degrees Centigrade and easily soluble in warm
alcohol, benzene and toluene.
The aqueous liquids obtained, when treating the original reaction product
with sodium carbonate solution, contain the acid camphoric guajacolether. These
liquids are acidulated and extracted with ligroine. The ligroine solution is
freed from moisture by means of calcium chloride. After distilling off the
ligroine the acid ether remains as a thick colourless oil.
In the foregoing examples the guajacol can be replaced by pyrocatechin
monoethylether, or other homologues.
1
1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: The Manufacture and Production of Camphoric Ethers of the
Pyrocatechinmonoalkylethers.
I, GEORGE WILLIAM JOHNSON, of 47, Lincoln's Inn Fields, in the County of
London, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by Kalle & Co., of Biebrich-on-Rhine,
in the Empire of Germany) and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement:-
This invention relates to the preparation of camphoric acid ethers of the pyro-
catechinmonoalkylethers. My foreign correspondents have found that these ethers
are best obtained by heating the two ingredients (camphoric acid and pyro-
catechinmonoalkylether) either dissolved in a neutral solvent, or in solid form,
together with a condensing agent such as phosphorus oxychloride.
The reaction does not proceed very evenly and smoothly when a solvent is
used. Besides varying quantities of camphoric anhydride the neutral as well as
the acid ether is formed. The two ethers can however be separated by treating
the product of the reaction with alkaline carbonates, which dissolve the acid
ether and leave the neutral ether behind. The neutral ethers are solid crystal-
line bodies, whilst the acid ethers are mostly liquids.
This invention may be carried out as follows:-but the invention is not limited
to the precise details.
EXAMPLE.
A solution of 20 kilos. of camphoric acid and 24'8 kilos. of guajacol, in 35 litres
of toluene, is kept slowly boiling whilst 17 kilos. of phosphorus oxychloride are
slowly run into the said solution. After boiling the mixture for 15 to 20 hours
the solution is poured off from the resinous matter which is formed during the
reaction, and washed well with dilute sodium carbonate solution. The toluene
solution is then treated with dilute caustic soda lye in order to extract some
unchanged guajacol.
The toluene is now distilled off. The residue contains, besides camphoric
diguajacolether, some camphoric anhydride. In order to obtain the ether in
a pure state the residue is recrystallized say twice from methyl alcohol.
The pure camphoric diguajacolether crystallizes in white needles melting at
a temperature of 125-126 degrees Centigrade and easily soluble in warm
alcohol, benzene and toluene.
The aqueous liquids obtained, when treating the original reaction product
with sodium carbonate solution, contain the acid camphoric guajacolether. These
liquids are acidulated and extracted with ligroine. The ligroine solution is
freed from moisture by means of calcium chloride. After distilling off the
ligroine the acid ether remains as a thick colourless oil.
In the foregoing example the guajacol can be replaced by pyrocatechin mono-
ethyl-ether, or other homologues.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
The manufacture or production of the acid and neutral camphoric ethers of

page_text: the pyrocatechinmonoalkylethers by heating the pyrocatechinmonoalkylethers with
camphoric acid in the presence of a condensing agent, and working up the
reaction-mass, to separate the neutral from the acid ethers, in the manner herein-
before described.
Dated this 6th day of February 1899
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.