Process for Producing the Salts of Aniline and its Alkyl Derivatives and of all its Homologues.
Year: 1895

page_text: Date of Application, 22nd Aug., 1895
Complete Specification Left, 22nd June, 1896-Accepted, 22nd Aug., 1896
Appication, con Aug., 1090
Complete Specification Left, 22nd June, 1896-Accepted. 22nd Aug.. 1898
PROVISIONAL SPECIFICATION.
Process for Producing the Salts of Aniline and its Alkyl Derivatives
and of all its Homologues.
I, Dr. ADOLF WELTER, Chemist, of No. 242 Königstrasse Crefeld, in the
Empire of Germany, do hereby declare the nature of this invention to be as
follows:-
:-
The technical process hitherto in use for producing the salts of aniline and of its
alkyl derivatives and of all its homologues and in particular of the muriatic aniline,
consisted in mixing aniline with concentrated aqueous hydrochloric acid and in
separating, after cooling, by centrifugal action the eliminated crystals from the
adhering mother lye and then drying the crystals at moderate temperatures in
drying chambers or in vacuum drying stoves. The mother lye containing, owing
to the great solubility of the salt, still large quantities of the latter, was then either
evaporated in clay vessels placed in sand baths, or it was neutralised with lime and
by distilling with steam worked again to aniline.
The first process had the drawback that it was necessary to work in sand baths
requiring an expensive firing and where the clay vessels placed therein could easily
burst, that the evaporation, in consequence of a superficial incrusting, took place
with difficulty, and that finally a portion of the salt sublimated in the air and
dissociated, while the second process always gave losses.
These inconveniences are entirely avoided by neutralising, say, for manufacturing
muriatic aniline, aniline with aqueous hydrochloric acid of any suitable concen-
tration and in drying this salt solution in a vacuum in enamelled flat cast iron
vessels, placed in boiling water or surrounded by steam not in tension. In an
extraordinarily short space of time, simultaneously with the water, the hydrochloric
acid in excess (if any) distills over together with the impurities of the aniline, such
as hydrocarbons, nitro-hydrocarbons and the like, while the aniline salt remains in
the enamelled vessel as an easily friable crystal cake.
Moreover it has not yet been possible to obtain the salts of the alkyl derivatives
of the aniline in a neutral anhydrous crystallized form. In the literature on the
subject they are described, as far as is known, as sirups.
In the process hitherto used for producing the salts of the secondary and tertiary
bases, owing to the high temperatures required, a dissociation always takes place,
so that there remains one or the other component part in excess. Furthermore it
has not yet been possible to separate in this manner the whole of the water from
the mass.
All these difficulties are avoided at once by producing the salts according to my
above described process, and I obtain these salts in an anhydrous completely
neutral crystalline form.
The very important advantages of the new process are as follows:
1. The desired salt is obtained directly and without any loss.
2. The salt is entirely freed from the impurities of the employed oil, say of the
hydrocarbons, nitrohydrocarbons &c., which in certain purposes of application
cause serious disadvantages.
3. The salts of the volatile acids remain in a completely neutral condition.
4. The salts can be isolated, in comparison with the older method, in much
f time

page_text: 5. Even weak oleiferous aqueous lyes can be worked to salt according to my
process in an economical manner.
6. Moreover it is possible to produce in this manner technically important salts,
say, of anilines, which at ordinary air pressure cannot be obtained without
decomposition, 80, for instance, nitrate of aniline forms easily nitraniline and
BO on.
7. As in my process only a temperature of boiling water is used, the inner
temperature being scarcely higher than 60°,-which alone constitutes already a
considerable technical improvement,-decompositions of the product, as they occur
at higher temperatures, are quite excluded.
8. The technics require sometimes, for instance in dyeing and printing, that the
several bases can be employed in quite determined mutual proportions as salts.
While this has been obtained hitherto only approximately by mechanically mixing
the several salts, by the new process, any desired mixture of the bases in the form
of salts can be produced in a completely homogeneous state.
9. As is commonly known, the tertiary bases show a great tendency of passing
over with hydrochloric acid at higher temperatures, splitting off an alkyl group in
the form of halogenalkyl and passing to secondary bases. In the same manner
and under similar conditions secondary bases are reduced to primary ones.
an unwished for reaction is entirely excluded in the salt production carried out
according to my process.
Such
10. The manufacturing costs of the salts of the aniline and of the other mentioned
bodies produced according to my process, are, as results from the above given
explanations, considerably lower than in the processes hitherto employed especially
as the output is a quantitative one and the working expenses are very considerably
reduced.
Dated this 22nd day of August 1895.
ABEL & IMRAY,
Agents for the Applicant.
Process for Producing the Salts of Aniline and its Alkyl Derivatives
and of all its Homologues.
I, Dr. ADOLF WELTER, Chemist, of 242 Königstrasse Crefeld, in the Empire
of Germany, 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 :-
The technical process hitherto in use for producing the salts of aniline and of its
alkyl derivatives and of all its homologues and in particular of the muriatic aniline,
consisted in mixing aniline with concentrated aqueous hydrochloric acid and in
separating, after cooling, by centrifugal action, the eliminated crystals from the
adhering mother lye and then drying the crystals at moderate temperatures in
drying chambers or in vacuum drying stoves. The mother lye containing, owing
to the great solubility of the salt, still large quantities of the latter, was then either
evaporated in clay vessels placed in sand baths, or it was neutralised with lime and
by distilling with steam worked again to aniline.
The first process had the drawback that it was necessary to work in sand baths
requiring an expensive firing, and where the clay vessels placed therein could easily
burst, that the evaporation, in consequence of a superficial incrusting, took place
with difficulty, and that, finally, a portion of the salt sublimated in the air and
dissociated, while the second process always gave losses.
These inconveniences are entirely avoided by neutralising, say, for manufacturing

page_text: muriatic aniline, aniline with aqueous bydrochloric acid of any suitable concen-
tration and in drying this salt solution in a vacuum in enamelled flat cast iron or
other suitable vessels placed in boiling water or surrounded by steam not in tension.
In an extraordinarily short space of time, simultaneously with the water, the
hydrochloric acid in excess (if any) distils over together with the impurities of
the aniline, such as hydrocarbons, nitro-hydrocarbons and the like, while the aniline
salt remains in the enamelled vessel as an easily friable crystal cake.
Morcover it has not yet been possible to obtain the salts of the alkyl derivatives
of the aniline in a neutral anhydrous crystallised form. In the literature on the
subject they are described, as far as is known, as sirups.
In the process hitherto used for producing the salts of the secondary and tertiary
bases, owing to the high temperatures required, a dissociation always takes place,
so that there remains one or the other component part in excess. Furthermore, it
has not yet been possible to separate in this manner the whole of the water from
the mass.
All these difficulties are avoided at once by producing the salts according to my
above described process, and I obtain these salts in an anhydrous, completely
neutral, crystalline form.
The very important advantages of the new process are as follows:
1. The desired salt is obtained directly and without any loss.
2. The salt is entirely freed from the impurities of the employed oil, say of the
hydrocarbons, nitrobydrocarbons &c., which in certain purposes of application
cause serious disadvantages.
3. The salts of the volatile acids remain in a completely neutral condition.
4. The salts can be isolated, in comparison with the older method, in much
shorter space of time.
5. Even weak oleiferous aqueous lyes can be worked to salt according to my
process in an economical manner.
6. Moreover, it is possible to produce in this manner technically important salts,
say, of anilines, which at ordinary air pressure cannot be obtained without
decomposition, so, for instance, nitrate of aniline forms easily nitraniline and
80 on.
7. As in my process only a temperature of boiling water is used, the inner
temperature being scarcely higher than 60° C.,-which alone constitutes already a
considerable technical improvement,-decompositions of the product, as they occur
at higher temperatures, are quite excluded.
8. Technical operators require sometimes, for instance in dyeing and printing,
that the several bases can be employed in quite determined mutual proportions as
salts. While this has been obtained hitherto only approximately by mechanically
mixing the several salts, by the new process, any desired mixture of the bases in
the form of salts can be produced in a completely homogeneous state.
9. As is commonly known, the tertiary bases shew a great tendency of passing
over with hydrochloric acid at higher temperatures, splitting off an alkyl group in
the form of halogenalkyl, and passing to secondary bases. In the same manner
and under similar conditions, secondary bases are reduced to primary ones. Such
an unwished for reaction is entirely excluded in the salt production carried out
according to my process.
10. The manufacturing costs of the salts of the aniline and of the other mentioned
bodies produced according to my process, are, as results from the above given
explanations, considerably lower than in the processes hitherto employed especially
as the output is a quantitative one and the working expenses are very considerably
reduced.
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 :-
For producing the salts of the anilines and of its alkylderivatives and of all its

page_text: homologues, a process consisting in neutralizing the said bodies with the calculated
quantity of an aqueous acid and in drying up the aqueous salt solution in flat
enamelled vessels in vacuo, substantially as set forth.
Dated this 22nd day of June 1896.
ABEL & IMRAY,
Agents for the Applicant.