The Manufacture of Monohalogen Derivatives of Aromatic Nitra- mines and Colouring Matters derived therefrom.
Year: 1898

page_text: The Manufacture of Monohalogen Derivatives of Aromatic Nitra-
mines and Colouring Matters derived therefrom.
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, do hereby declare
the nature of this invention (which has been communicated to me from abroad by
Leopold Cassella & Co., of Frankfort-on-Main, in the Empire of Germany, Manufac-
turing Chemists,) to be as follows:-
The first attempts to introduce chlorine into p. nitraniline were made by Koerner.
He obtained resinous products which he surmised contained dichlornitraniline, but he
did not succeed in isolating this body. The experiments were later on repeated by
Witt who actually obtained a dichlornitraniline having the melting point of 188° C.
My correspondents have now found that if 2 atoms of chlorine are allowed to react on
1 molecule of p. nitraniline in a mineral acid solution at a low temperature, monochloride
of paranitraniline is formed and that certain isomers and homologues of p. nitraniline
behave in an analogous way.
•
The method is practically carried out by introducing a stream of chlorine into a
concentrated muriatic acid solution of the nitro bases or by addition of a solution of
hypochlorite of sodium, care being taken that the whole is well cooled.
EXAMPLE.
-
34.5 kilos. of paranitraniline are dissolved in 200 kilos. concentrated muriatic acid,
400 kilos. of ice are added, the whole cooled to 10° C. and chlorine is then slowly
introduced in such a manner that the temperature does not rise above 0° and until
an increase in weight of 18 kilos. has taken place. During the operation the greater
part of the nonochlorparanitraniline precipitates. Finally the solution is diluted with
water and the yellow precipitate is filtered off. The product is obtained in an almost
chemically pure state. By recrystallising once, for instance, from diluted acetic acid
of 25 per cent. pure o. chlor-p. nitraniline with a melting point of 105° C. is obtained.
The orthochlorparanit raniline thus obtained may be used for the production of very
valuable azo derivatives, which are distinguished from the known analogous deriva-
tives of paranitraniline by their materially different shades, mostly considerably bluer,
and their greater fastness to acid and light. Of the simple monoazo derivatives two
groups are of special importance; firstly the direct products of the various combina-
tions with o. chlor-p. nitro-diazobenzol and secondly the amido derivatives of these
products, obtainable by cautious reduction. The following are examples of the
processes:-
T

page_text: is cooled to about 5° C. and a solution of about 23 parts by weight of beta naphty-
lamine sulpho acid F, containing an excess of acetate of soda is added. The solution
is then made slightly alkaline by the addition of soda, heated to about 50° C., and the
dyestuff which precipitates, is filtered off. It dyes wool a bright blueish red.
EXAMPLE 2.
J
The solution of chlornitrodiazobenzene, obtained as above described, is added to a
solution of 26-2 parts by weight of gamma amidonaphtolsulphonate of soda containing
an excess of acetate of sodium. The whole is made alkaline by the addition of 360
parts by weight of caustic soda; then a solution of 125 parts by weight of sulphide of
sodium crystals is added at a temperature of about 35° C., with brisk stirring. After 1
about 12 hours the reaction is terminated and the blueish violet colour of the solution
has turned red. The dyestuff is precipitated with salt and filtered off.
The dyestuffs obtainable in an analogous manner from some other components dye
the following shades:
aa,
a8,
aaa naphtolsulpho acid
BBB, naphtoldisulpho acid R
B.Ba, naphtoldisulpho acid
B.B.Ba, naphtoltrisulpho acid
a,az naphtylaminesulpho acid
naphtylaminesuipho acid
naphtylaminesulpho acid
a. naphtylaminesulpho acid
aa naphtylaminesulpho acid
Ethyl aa, naphtylaminesulpho
BB, naphtylaminesulpho acid
B.B, naphtylaminesulpho acid
a naphtylaminedisulpho acid
8 naphtylamine B.B, disulpho a
a, amido a naphtola, sulpho ac
B, amido a naphtol B, sulpho
alkaline solution)
B, amido a naphtol
acid solution)
a
sulpho
amidonaphtol Bẞ, disulph
in alkaline solution)
a,a, amidonaphtol BB, disulpho
acid solution)
aa, dioxynaphtalene a, sulpho a
a,a, dioxynaphtalene BB, disul
a.a, dioxynaphtalene ẞa, disulp

page_text: The Manufacture of Monohalogen Derivatives of Aromatic Nitra-
mines and Colouring Matters derived therefrom.
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, do hereby declare
the nature of this invention (which has been communicated to me from abroad by
Leopold Cassella & Co., of Frankfort-on-Main, in the Empire of Germany, Manufac
turing Chemists,) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:—
The first attempts to introduce chlorine into p. nitraniline were made by Koerner,
Gazetta chimica, 1874. He obtained resinous products which he surmised contained
dichlornitraniline, but he did not succeed in isolating this body. The experiments
were later on repeated by Witt, Berichte VIII., page 144, who actually obtained a
dichlornitraniline having the melting point of 188° C. My correspondents have now
found that if 2 atoms of chlorine are allowed to react on 1 molecule of p. nitraniline
in a mineral acid solution at a low temperature monochloride of paranitraniline is
formed and that certain isomers and homologues of p. nitraniline behave in an
analogous way.
The method is practically carried out by introducing a stream of chlorine into a
concentrated muriatic acid solution of the nitro bases or by addition of a solution of
hypochlorite of sodium care being taken that the whole is well cooled.
EXAMPLE.
-
34.5 kilos. of paranitraniline are dissolved in 200 kilos. concentrated muriatic
acid, 400 kilos. of ice are added, the whole cooled to 10° C. and chlorine is then
slowly introduced in such a manner that the temperature does not rise above 0° and
until an increase in weight of 18 kilos. has taken place. During the operation the
greater part of the monochlorparanitraniline precipitates. Finally the solution' is
diluted with water and the yellow precipitate is filtered off. The product is obtained
in an almost chemically pure state. By recrystallising once, for instance, from
diluted acetic acid of 25 per cent., pure o. chlor-p. nitraniline with a melting point
of 105° C. is obtained.
Or: A solution of 18-8 kilos. of hypochlorite of sodium is slowly introduced into
the well cooled solution of 34.5 kilos. of paranitraniline. The manner of preparing
this solution and of isolating the monochlorparanitraniline is the same as described
in the first example.
The orthochlorparanitraniline thus obtained may be used for the production of
very valuable azo derivatives, which are distinguished from the known analogous
derivatives of paranitraniline by their materially different shades, mostly considerably
bluer, and their greater fastness to acid and light. Of the simple monoazo derivatives
two groups are of special importance; firstly the direct products of the various
combinations with o. chlor-p. nitrodiazobenzol, and secondly the amido derivatives of
these products, obtainable by cautious reduction. The following are examples of the
processes :-
EXAMPLE 1.
50 parts by weight of o. chlor-p. nitraniline are dissolved in 600 parts by weight of
acetic acid (50 per cent.) 350 parts by weight of muriatic acid are added and then a
concentrated solution of 20-7 parts by weight of nitrite of soda is allowed to flow in
at a temperature of about 30° C. As soon as the reaction is terminated the diazo
solution is cooled to about 5° C. and a solution of about 23 parts by weight of beta naph-
tylamine sulpho acid F, containing an excess of acetate of soda is added. The solution

page_text: is then made slightly alkaline by the addition of soda, heated to about 50° C., and
the dye stuff which precipitates, is filtered off. It dyes wool a bright blueish red,
EXAMPLE 2.
The solution of chlornitrodiazobenzene, obtained as above described, is added to a
solution of 26-2 parts by weight of gamma amidonaphtolsulphonate of soda containing 5
an excess of acetate of sodium. The whole is made alkaline by the addition of
360 parts by weight of caustic soda; then a solution of 125 parts by weight of sulphide
of sodium crystals is added at a temperature of about 35° C., with brisk stirring.
After about 12 hours the reaction is terminated and the blueish violet colour of the
solution has turned red. The dyestuff is precipitated with salt and filtered off.
The dyestuffs obtainable in an analogous manner from some other components dye
the following shades:
1
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The production of chlornitraniline by allowing two atoms of chlorine to
react upon one molecule of paranitraniline, dissolved in mineral acid substantially as
described.

page_text: 2. The production of colouring matters by combining orthochlorparanitrodiazo-
benzol with amines or phenols substantially as described.
3. The production of colouring matters by reducing the nitro-group in the colouring
matters referred to in Claim 2, substantially as described.
4. The herein before described new materials and colouring matters.
Dated thin 6th
1000