Year: 1896

page_text: Date of Application, 22nd Dec., 1896
Complete Specification Left, 10th July, 1897-Accepted, 14th Aug.. 1897

page_text: Pure acetosulphanilate of sodium may also serve for the production of other pure
acetosulphanilate salts, of which in particular acetosulphanilate of magnesiuin and
acetosulphanilate of iron have been found of value as medicines.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Manufacture of Pure Acetosulphanilate Salts.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the County
of London, Chartered Patent Agent, do hereby declare the nature of this invention
(which has been communicated to me from abroad by F. Hoffmann-La Roche & Co.,
of Basle, Switzerland, Manufacturing Chemists) and in what manner the same is
to be performed to be particularly described and ascertained in and by the following
statement :-
Professor Nietzki of Basle has mentioned in Berl. Ber. 17. p. 1707 that sulphanilic
acid cannot itself be acetylated, but only its salts, and that acetosulphanilic acid
cannot be produced in the free state.
was endeavouring to determine the composition of sulphanilic acid,
and therefore he did not further pursue the production of pure acetosulphanilate
salts.
My foreign correspondents have now found that glacial acetic acid is quite
sufficient to effect the acetylation of sulphanilate of sodium as also of other alkaline
metals.
Besides the main reaction according to the equation
there are formed small quantities of free sulphanilic acid and acetate of sodium as
may be found by testing the product of the reaction.
The former remains undissolved when the product of the reaction is dissolved in
half its weight of water, whilst the latter can be extracted from the melted mass by
means of alcohol of high strength.
Example. Equal parts of p. sulphanilate of sodium and glacial acetic acid are
heated to boiling point in a return-flow cooler and kept boiling during 6 to 8 hours.
The acetic acid in excess is then distilled off as far as possible and the
residue is dissolved in the least possible quantity (about half its weight) of hot
water. The solution is separated by filtration from the undissolved portion, and is
precipitated in the cold by means of alcohol of 98 to 99 per cent. The precipitate
is collected, washed in strong alcohol, treated in a centrifugal extractor and dried.
Instead of alcohol alone, alcohol with a subsequent addition of ether can be
employed to effect the precipitation. In such a case however it is necessary to
remove the acetate of sodium from the product of reaction by boiling with spirits of
wine before the said product is dissolved in water.
The final product, obtained in the one way or the other, is readily soluble in water,
soluble with difficulty in alcohol, and insoluble in ether. The aqueous solution
when mixed with a solution of iron chloride (reagent) does not give the reaction of
acetate of sodium (red colour), and consists of a white hygroscopic substance in

page_text: minute crystals. The pure acetosulphanilate of sodium is employed as an
antipyretic and excels antifebrine in being soluble in water and therefore in acting
more rapidly.
Pure acetosulphanilate of sodium may also serve for the production of other pure
acetosulphanilate salts, of which in particular acetosulphanilate of magnesium and
acetosulphanilate of iron have been found of value as medicines.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
1. The herein described manufacture of pure alkaline acetosulphanilate by
separating free acetosulphanilic acid and alkaline acetate from the impure alkaline
acetosulphanilate produced by acetylating an alkaline sulphanilate by glacial acetic
acid.
The nuro alkaline anctosulphanilatos manufactured as above not forth
Dated this 10th day of July 1897.
ABEL & IMRAY,
Agents for the Applicant.