Manufacture of 1 Naphthylamine 3, 6, 8-Trisulpho Acid from 1 Nitronaphthalin 3, 8-Disulpho Acid.
Year: 1894

page_text: Date of Application, 9th Apr., 1894
Complete Specification Left, 5th Dec., 1894-Accepted, 5th Jan., 1895
PROVISIONAL SPECIFICATION.
[Communicated from abroad by the Firm of A. FISCHESSER & Co., of
Lutterbach, near Mülhausen, Alsace, Germany, Manufacturers.]
Manufacture of 1 Naphthylamine 3, 6, 8-Trisulpho Acid from
1 Nitronaphthalin 3, 8-Disulpho Acid.
I, CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery
Lane, in the County of London, Consulting Engineer and Chartered Patent Agent,
do hereby declare the nature of this invention to be as follows:-
:―
My correspondents have discovered that on treating certain nitro-naphthalin-,
sulpho-acids with sulphite salts there is no formation of the corresponding amido-
naphthalin-sulpho-acids, such as should have been expected, but that besides the
reduction of the nitro group, a sulpho group simultaneously enters into the
naphthalin nucleus, so that an amidonaphthalinsulpho acid is produced which
contains one sulpho group more than the nitronaphthalinsulpho-acid employed.
This reaction does not succeed with all nitronaphthalinsulpho acids; according to
the nature thereof, there is sometimes produced the corresponding amido acid,
sometimes that containing an additional sulpho group.
My correspondents have followed the reaction more particularly in the 1 nitro-
naphthalin 3, 8,-disulpho acid (German Patents 45776 and 52724), and have found
that it is converted into the 1 naphthylamine 3, 6, 8, trisulpho acid of German
Patent 56058. For the transformation all neutral or acid sulphites soluble in
water may be used; sodium bisulphite is chosen by preference, and the process is,
by preference, carried out as follows:-
50 kilos. of 1 nitronaphthalin-3, 8-disulphonate of soda are dissolved in 500 litres
of hot water and there is added a concentrated solution of 75 kilos. of sodium
bisulphite.
The liquid assumes a deep orange yellow colour; it is heated until this colour is
changed into light yellow, and is then strongly supersaturated with hydrochloric
acid and heated for some time to boiling point. The liquid is then allowed to cool,
whereupon (if necessary, after further concentration) the acid soda salt of the
1 naphthylamine 3, 6, 8, trisulpho acid, which is soluble with difficulty in the
solution, crystallises out. It has after drying at 120° C., the composition

page_text: Manufacture of 1 Naphthylamine. 3, 6, 18-Trisulpho Acid from
1 Nitronaphthalin 3, 8-Disulpho Acid.
I, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery
Lane, in the County of London, Consulting Engineer and Chartered Patent
Agent, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :--
My correspondents have discovered that on treating certain nitro naphthalin-
sulpho-acids with sulphite salts there is no formation of the corresponding amido-
naphthalin-sulpho-acids, such as should have been expected, but that besides the
reduction of the nitro group, a sulpho group simultaneously enters into the
naphthalin nucleus so that an amido naphthalin-sulpho acid is produced which
contains one sulpho group more than the nitronaphthalin-sulpho-acid employed..
This reaction does not succeed with all nitronaphthalin sulpho acids; according to
the nature thereof, there is sometimes produced the corresponding amido acid,
sometimes that containing an additional sulpho group.
My correspondents have followed the reaction more particularly in the 1 nitro-
naphthalin 3, 8-disulpho acid (German Patents 45776 and 52724), and have found
that it is converted into the 1 naphthylamine 3, 6, 8, trisulpho acid of German
Patent 56058. For the transformation all neutral or acid sulphites soluble in
water may be used; sodium bisulphite is chosen by preference, aud the process is,
by preference, carried out as follows:-
50 kilos. of 1 uitronaphthalin-3, 8 disulphonate of soda are dissolved in 500 litres.
of hot water and there is added a concentrated solution of 75 kilos. of sodium
bisulphite.
•
The liquid assumes a deep orange yellow colour; it is heated until this colour is
changed into light yellow, and is then strongly supersaturated with hydrochloric
acid and heated for some time to boiling point. The liquid is then allowed to cool,
whereupon (if necessary, after further concentration) the acid soda salt of the
1 naphthylamine 3, 6, 8, trisulpho acid, which is soluble with difficulty in the
solution, crystallises out. It has after drying at 120°, the composition
À comparison of the naphthylamine trisulpho-acid obtained in this manner with
that prepared according to the process of German Patent 56058 proved the perfect
identity of both products.
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
Manufacture of 1 naphthylamine 3, 6, 8 trisulpho acid by the reduction of
1 nitro-naphthalin 3, 8 disulpho acid by means of sulphite salts, substantially as
described.
Dated this 5th day of December 1801
ABEL & IMRAY,
Agents for the Applicant.