Improvements in the Manufacture of Guaiacol.
Year: 1897

page_text: Date of Application, 19th Mar., 1897
Complete Specification Left, 20th Dec., 1897-Accepted, 29th Jan., 1898
Improvements in the Manufacture of Guaiacol.
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 by. Kalle & Co., of Biebrich-on-Rhine, in the Empire
of Germany, to be as follows:-
This invention relates to the manufacture of pure guaiacol by decomposing
diazotized orthoanísidine. In order to prevent the formation of valueless bye-
products the diazotized orthoanisidine is decomposed in such a manner that the
guaiacol formed is protected against the chemical action of further quantities of
the diazo-body subsequently introduced in the process. This is attained by run-
ning the diazo solution at a temperature exceeding 135° centigrade into dilute
sulphuric acid containing at least 35 per cent. of concentrated sulphuric acid.
The following is an example of the manner in which the invention may be
performed.
62 kilos of ortho-anisidine are stirred into a mixture of 400 kilos of ice-water
and 140 kilos of dilute sulphuric acid containing 50 per cent. of concen-
trated sulphuric acid. The orthoanisidine is then diazotized by adding a solution
of 34-5 kilos of sodium nitrate in 100 litres of water. The diazo solution obtained
is run into a distilling apparatus containing a mixture of 300 litres of water 550
kilos of concentrated sulphuric acid and 400 kilos of calcined sulphate of soda,
which mixture has previously been heated up to from 135° to 1400 centigrade.
Whilst the diazo solution is running into the mixture the temperature is kept
above 135° centigrade by heating the still.
In this manner the guaiacol is vapourized and carried over by the distilling
water as soon as it is formed by the decomposing action of the hot dilute sulphuric
acid upon the diazotized ortho-anisidine.
After the reaction is finished the receiver of the distilling apparatus contains
besides some separated guaiacol an aqueous solution of guaiacol. From this
aqueous solution the guaiacol is precipitated by adding common salt. The whole
mass is then extracted by means of a suitable solvent such for instance as ether.
After the solution of guaiacol so obtained has been freed from moisture by means
of calcined chloride of calcium or other body suitable for the purpose, the solvent
is distilled off.
The remaining guaiacol may be further purified by distillation. It distils at
2000 centigrade and becomes a solid crystalline mass at about 30° centigrade.
Dated this 19th day of March 1897.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: Improvements in the Manufacture of Guaiacol.
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 manufacture of pure Guaiacol by decomposing
diazotised ortho-anisidine. In order to prevent the formation of valueless bye-
products the diazotised ortho-anisidine is decomposed in such a manner that the
guaiacol formed is protected against the chemical action of further quantities
of the diazo-body subsequently introduced in the process. This is attained by
running the diazo solution at a temperature exceeding 135° centigrade into dilute
sulphuric acid containing at least 35 per cent. of concentrated sulphuric acid.
The following is an example of the manner in which the invention may be
performed.
62 kilos of ortho-anisidine are stirred into a mixture of 400 kilos of ice-water
and 140 kilos of dilute sulphuric acid, containing 50 per cent. of concentrated
sulphuric acid. The ortho-anisidine is then diazotised by adding a solution of
345 kilos of sodium nitrite in 100 litres of water. The diazo solution obtained
is run into a distilling apparatus containing a mixture of 300 litres of water
550 kilos of concentrated sulphuric acid and 400 kilos of calcined sulphate of soda,
which mixture has previously been heated up to from 135 to 140° centigrade.
Whilst the diazo solution is running into the mixture the temperature is kept
above 135° centigrade by heating the still.
In this manner the guaiacol is vapourised and carried over by the distilling
water and as soon as it is formed by the decomposing action of the hot dilute
sulphuric acid upon the diazotised ortho-anisidine.
After the reaction is finished the receiver of the distilling apparatus contains
besides some separated guaiacol an aqueous solution of guaiacol. From this
aqueous solution the guaiacol is precipitated by adding common salt. The whole
mass is then extracted by means of a suitable solvent such for instance as ether.
After the solution of guaiacol so obtained has been freed from moisture by means
of calcined chlorate of calcium or other body_suitable for the purpose, the solvent
is distilled off.
The remaining guaiacol may be further purified by distillation. It distils
at 2000 centigrade and becomes on cooling a solid crystalline mass which melts
at about 30° centrigade.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
The manufacture of guaiacol by decomposing diazo-anisol by boiling the diazo-
anisol with sulphuric acid of at least 35 per cent. at a temperature above 135°
centigrade so that the guaiacol formed is directly protected against further action
of the diazo solution.
December 19077
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.