Process or Processes for Obtaining Certain Toluene Derivatives from the Mixed Nitro-toluenes obtained by Nitrating Toluene.
Year: 1894

page_text: Date of Application, 1st Feb., 1894
Complete Specification Left, 26th Oct., 1894-Accepted, 1st Dec., 1894
PROVISIONAL SPECIFICATION.
Process or Processes for Obtaining Certain Toluene Derivatives from
the Mixed Nitro-toluenes obtained by Nitrating Toluene.
I, HANS LOESNER, Doctor of Philosophy, of 48 Windmühlenstrasse, Leipzig,
in the Kingdom of Saxony, do hereby declare the nature of this invention to be as
follows:-
If aromatic nitro-compounds are reduced by means of salts of arsenious acid
(arseniates), amido-bodies are produced in addition to azoxy-compounds.
Ortho-substitution compounds of nitro-bodies, however, such as ortho-nitro-
toluene, are not or scarcely at all affected by these reducing agents.
This property of the arseniates may be utilized for separating the individual
nitro-compounds from a mixture of ortho-meta- and para-nitro-compounds, such as
is frequently obtained in the nitration of aromatic bodies for instance toluene.
If a mixture of ortho-meta- and para-nitro-toluene with arsenious acid is
digested in alkaline solution, only the meta- and para-compounds are reduced while
ortho-nitro-toluene remains practically unaffected. The latter may be easily
separated from the azoxy amido-compounds by known methods.
It is advantageous to operate with the use of pressure, in order to facilitate and
simplify the reaction.
EXAMPLES.
1. 50 grammes of nitro-toluene, such as may be obtained by the nitration of
toluene, are heated with 50 grammes of arsenious acid, 65 g. of caustic soda (or
85 g. of caustic potash) and about 250 g. of water in suitable retorts or closed
vessels to a temperature ranging between 130 and 150° Centigrade and this
temperature is maintained from 8 to 24 hours.
The product of the reaction is scooped off the solution of alkali-arsenate, and the
amido-compounds resulting from the process are removed by means of hydrochloric
acid.
The oily residue contains ortho-nitro-toluene, meta- and para-azoxytoluene.
The nitro-toluene may now be separated from the azoxy-compounds by
distillation with steam.
2. 50 grammes of nitro-toluene are mixed with 50 grammes of arsenious acid,
65 g. of caustic soda (or 85 g. of caustic potash) and about 500 g. of water, and
the mixture heated to the boiling point from 12 to 24 hours while constantly
stirring, after which the treatment is continued as in the first example.
Dated this 25th day of January 1894.
FAIRFAX & WETTER,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Process or Processes for Obtaining Certain Toluene Derivatives from
the Mixed Nitro-toluenes obtained by Nitrating Toluene.
I, HANS LOESNER, Doctor of Philosophy, of 48 Windmühlenstrasse, Leipzig,
in the Kingdom of Saxony, 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 :-
If aromatic nitro-compounds are reduced by means of salts of arsenious acid
Price 8d.1

page_text: (arsenites), as described in my application for a Patent No. 1555 of 1894, amido-
bodies are produced in addition to azoxy-compounds.
Ortho-substitution compounds of nitro-bodies however, such as ortho-nitro-
toluene, are not or scarcely at all affected by these reducing agents.
This property of the arsenites may be utilized for separating the ortho-nitro-
toluene from a mixture of ortho-meta- and para-nitro-toluene, such as is obtained
in the nitration of toluene.
If a mixture of ortho-meta-and para-nitro-toluene with arsenious acid is digested
in alkaline solution, only the meta- and para-compounds are reduced, while ortho-
nitro-toluene remains practically unaffected. The latter may be easily separated
from the amines and the azoxyderivatives of the toluene produced by the reduction,
by treatment with acids and distillation with steam, or by other known methods.
It is advantageous, to operate with the use of pressure, in order to facilitate and
simplify the reaction.
EXAMPLES.
1. 50 grammes of nitro-toluene, such as may be obtained by the nitration of
toluene, are heated with 50 grammes of arsenious acid, 65 g. of caustic soda (or
85 g. of caustic potash) and about 250 g. of water, in suitable retorts or closed
vessels, to a temperature ranging between 130 and 150° Centigrade, and this
temperature is maintained from 8 to 24 hours.
The product of the reaction is scooped off the solution of alkali arseniate, and
the amido-compounds resulting from the process are removed by means of hydro-
chloric acid.
The oily residue contains ortho-nitro-toluene, meta- and para-azoxytoluene.
The nitro-toluene may now be separated from the azoxy-compounds by
distillation with steam.
2. 50 grammes of nitro-toluene are mixed with 50 grammes of arsenious acid,
65 g. of caustic soda (or 85 g. of caustic potash) and about 500 g. of water, and
the mixture is heated to the boiling point from 12 to 24 hours while constantly
stirring, after which the treatment is continued as in the first example.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The process for obtaining pure ortho-nitro-toluene from the mixed nitro-toluenes
obtained by nitrating toluene, which consists in reducing the said mixture by
heating with arsenites, as described in the Patent Specification No. 1555 of
1894, and separating the unaltered o-nitro-toluene from the amines and azoxy-
derivatives of the toluene produced by the reduction, by treatment with acids and
distillation with steam, or by other known methods, substantially as described.
Dated this 24th day of October 1894.
FAIRFAX & WETTER,
433, Strand, London, Agents.