Improvements in Mono-alkyl Ethers of Pyro-catechin, and in the Production of such Ethers.
Year: 1896

page_text: Date of Application, 20th July, 1896-Accepted, 22nd Aug., 1896
COMPLETE SPECIFICATION.
Improvements in Mono-alkyl Ethers of Pyro-catechin, and in the
Production of such Ethers.
A communication from abroad by the CHEMISCHE FABRIK VON HEYDEN, GESELL-
SCHAFT MIT BESCHRAENKTER HAFTUNG, of Radebeul, near Dresden, Saxony,
German Empire, Manufacturers.
I, JOHN CLAYTON MEWBURN of the Firm of J. C. Mewburn and Ellis, of 55 and 56
Chancery Lane, in the County of London, Chartered Patent Agents, do hereby
declare the nature of the said invention 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 a new and hitherto unknown substance, -ethyl-ether of
OH
CH,OC₂H,.
pyro-catechin which has the chemical formula
This new substance
possesses a very remarkable capability or power of crystallization. It crystallizes
into large, well developed glass-bright, colorless prisms, which easily melt. The point
of setting or solidification is at 26 to 27° C. The substance boils at 215° C. It is
very difficultly soluble in water, easily soluble in alcohol and ether and in a dilute
ONa
aqueous soda lye, in which latter the natrium salt
CH.OC₂H,
is formed. If
concentrated soda lye is used, the soda salt is immediately separated in solid form as a
white crystalline mass. The new substance has an agreeable aromatic smell,
resembling to a certain degree the smell of thymol. It is useful for the production of
odoriferous substances and as an antiseptic.
By Heinisch in the Vienna Journal (Monatshefte fur Chemie 15, page 152) a
substance has already been described, which the discoverer supposed to be ethyl-ether
of pyrocatechin
он
CH,OC₂H.
This supposition however has proved to be an
error; the substance described by Heinisch is not the mono-ethylether of pyro-
catechin.
The substance described by Heinisch is an uncrystallizable liquid, while the mono-
ethylether of pyrocatechin is a solid substance, characterized by a very ready capacity
or power to crystallize. Heinisch's substance boils at 240° to 241° C, while the
monoethylether of pyro-catechin boils at 215° C.
The production of the mono-ethylether of pyrocatechin is a very simple one; it
may be effected by ethylating the pyrocatechin and alcohol in the presence of a
dehydrating agent; or by heating the pyrocatechin salts with halogen-ethyl or with
an ethylsulphate. The best way of proceeding is the following :-

page_text: of 14-8 kilogrammes of ethylsulphate of sodium and 16 kilogrammes of water. After
thoroughly agitating this mixture, the same is digested for about 2 hours at a pressure
of about 2 to 3 atmospheres. Then the contents of the vessel are distilled off by
means of steam and the mono- and di-ethylether of pyrocatechin will distil over as
colorless oils. The mixture of the two ethyl ethers of pyrocatechin is then well mixed
with a solution of 4 kilogrammes of caustic soda in about 25 kilogrammes of water,
and after a certain period of rest the diethylether of pyrocatechin which has remained
undissolved is drawn off, and the mono-ethylether of pyrocatechin is separated from
the alkaline solution by an acid.
Instead of the solution of 14.8 kilogrammes of ethylsulphate of sodium 10-9 kilo-
grammes of bromethyl or 6-45 kilogrammes of chlorethyl may be used.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondents, and in what manner the
same is to be performed, I declare that what I claim is :-
1. The process of manufacturing mono-ethyl-ether of pyrocatechin, by ethylating
pyrocatechin, as and for the purposes described.
2. The new substance, mono-ethylether of pyro-catechin of the chemical formula
OH
CHOC,H,
and possessing the following characteristics: Difficultly soluble in water,
easily soluble in alcohol, in ether, in a diluted aqueous soda lye; solidifying with
concentrated soda lye into the white salt
ONa
CH.OC,H,,
which on addition of water
will liquefy; having an aromatic, slightly thymol like odor; having a boiling point
of 215° C.; crystallizing easily into colorless, bright, transparent prisms, its point of
solidification being 26° to 27° C.
3. The use of the said mono-ethyl ether of pyrocatechin as an antiseptic and for the
production of odoriferous substances.
Dated this 20th day of July 1896.
J. C. MEW BURN & ELLIS,
55 and 56 Chancery Lane, Loudon, Chartered Patent Agents.
J. C. MEW BURN & ELLIS,
55 and 56 Chancery Lane, Loudon, Chartered Patent Agents.