Manufacture of a New Dinitrosulphonic Acid of the Aromatic Series.
Year: 1899

page_text: Date of Application, 24th Mar., 1899
Complete Specification Left, 20th Dec., 1899-Accepted, 20th Jan., 1900
Manufacture of a New Dinitrosulphonic Acid of the Aromatic
Series.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of. this invention (as communicated to me from abroad by
The Actien Gesellschaft für Anilin Fabrikation, of Berlin, in the Empire of Germany,
Chemical Manufacturers) to be as follows:-
Dinitrochlorobenzenesulphonic acids have not yet been described and up to the
present time no process for their production is known. My foreign correspondents
have discovered a process for the production of a dinitrochlorobenzenesulphonic
acid having the following constitution:
This new acid has proved of great value as starting product for the preparation of
a large series of organic compounds owing to the fact that different radicles can be
very easily substituted for the chlorine atom contained in it.
The production of the new acid is effected by heating ortho-nitrochloro-benzene-
para-sulphonic acid or salts thereof with a mixture of fuming sulphuric acid and
strong nitric acid, as in the following example.
27.5 kilos. of the potassium salt of ortho-nitrochlorobenzene-para-sulphonic acid
are dissolved in 100 kilos. of fuming sulphuric acid containing 25 per cent. of
anhydride, and 15 kilos. of fuming nitric acid of 87 per cent. strength are then
added. This mixture is heated to 120° to 130° C., and after the nitration is complete
the product is thrown in water. The separated crystals are filtered and freed; by
recrystallisation from water, from an oily by-product.
Instead of starting from ortho-nitrochlorobenzene-para-sulphonic acid and intro-
ducing into it one nitro-group, the new acid can also be obtained by using
chlorobenzenesulphonic acid as starting product and successively introducing two
nitro-groups into this compound as illustrated by the following example.
34 kilos. of chlorobenzene are introduced into a mixture of 72 kilos. of concentrated
sulphuric acid (monohydrate) and 30 kilos. of fuming sulphuric acid containing
25 per cent. of anhydride. The mixture is then heated on the water bath until all
chlorobenzene has disappeared. 26 kilos. of fuming nitric acid of 87 per cent.
strength are added to the solution after cooling and the nitration is allowed to be
completed at 40° C.

page_text: After the product thus obtained has stood for two hours 100 kilos. of fuming
sulphuric acid containing 60 per cent. of anhydride and 40 kilos. of potassium nitrate
are added and the mixture is heated for two to three hours at 1209-130° C. The
new acid formed is isolated and purified in the manner described in the previous
example.
The potassium salt of dinitrochlorobenzene sulphonic acid is readily soluble in hot
water, little soluble in cold water and crystallizes from the solution in water in the
form of colourless needles; it melts at about 300° C. and decrepitates at a higher
temperature.
Manufacture of a New Dinitrosulphonic Acid of the Aromatic
Series.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of this invention (as communicated to me from abroad by
The Actien Gesellschaft für Anilin Fabrikation, of Berlin, in the Empire of Germany,
Chemical Manufacturers) and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement-
Dinitrochlorobenzenesulphonic acids have not yet been described and up to the
present time no process for their production is known.
My foreign correspondents have discovered a process for the production of a
dinitrochlorobenzenesulphonic acid having the following constitution :
This new acid has proved of great value as starting product for the preparation
of a large series of organic compounds owing to the fact that different radicles can
be very easily substituted for the chlorine atom contained in it. The production of
the new acid is effected by heating ortho-nitrochloro-benzene-para-sulphonic acid
or salts thereof with a mixture of fuming sulphuric acid and strong nitric acid, as in
the following example.
27.5 kilos. of the potassium salt of ortho-nitrochlorobenzene-para-sulphonic acid
are dissolved in 100 kilos. of fuming sulphuric acid containing 25 per cent. of
anhydride, and 15 kilos. of fuming nitric acid of 87 per cent. strength are then
added. This mixture is heated to 120° to 130° C., and, after the nitration is
complete, the product is thrown in water. The separated crystals are filtered and
freed, by recrystallisation from water, from an oily by-product.
Instead of starting from ortho-nitrochlorobenzene-para-sulphonic acid and intro-
ducing into it one nitro-group, the new acid can also be obtained by using

page_text: chlorobenzene-sulphonic acid as starting product and successively introducing two
nitro-groups into this compound as illustrated by the following example.
34 kilos. of chlorobenzene are introduced into a mixture of 72 kilos. of concentrated
sulphuric acid (monohydrate) and 30 kilos. of fuming sulphuric acid containing
25 per cent. of anhydride.
The mixture is then heated on the water bath until all chlorobenzene has
disappeared. 26 kilos. of fuming nitric acid of 87 per cent. strength are added to
the solution after cooling and the nitration is allowed to be completed at 40° C.
After the product thus obtained has stood for two hours, 100 kilos. of fuming
sulphuric acid containing 60 per cent. of anhydride and 40 kilos. of potassium nitrate
are added and the mixture is heated for two to three hours at 120°-130° C.
The new acid formed is isolated and purified in the manner described in the
previous example.
The potassium salt of dinitrochlorobenzene sulphonic acid is readily soluble in hot
water, little soluble in cold water and crystallizes from the solution in water in the
form of colourless needles; it melts at about 300° C. and decrepitates at a higher
temperature.
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 dinitrochlorobenzenesulphonic acid :