vormals FRIEDRICH The Manufacture or Production of a Sweet Compound, and of Certain Intermediate Products therefor.
Year: 1895

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c., Act, 1883) as required by
the decision of the Law Officer of the 2nd day of December 1896.
Date of Application, 1ith Mar., 1895
Complete Specification Left, 11th Dec., 1895-Accepted, 11th Jan., 1896
[Communicated from abroad by THE FARBENFABRIKEN,
BAYER & Co., of Elberfeld, Germany.]
vormals FRIEDRICH
The Manufacture or Production of a Sweet Compound, and of
Certain Intermediate Products therefor.
I HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows:-
My foreign correspondents have found that the ethers of orthosulphobenzoic
acid can be readily produced by treating the dipotassium salt, disodium salt, or the
like, of orthosulphobenzoic acid, with one molecular proportion of an alkyl haloid,.
or by heating the mono- or dipotassium salt, or the like, of orthosulphobenzoic
acid with the corresponding alcohols in the presence of agents (such as muriatic
acid, sulphuric acid, or the like) capable of removing water, in order to bring about
the formation of the ethers. On heating with the latter, or the like agents, the
salts of orthosulphobenzoic acid which are insoluble in alcohol, are gradually,
dissolved potassium chloride or the like being precipitated. When the reaction is
complete, the resulting liquid is filtered, in order to remove the salt formed during
the operation, and the filtrate is treated in a suitable manner, in order to remove
the alcohol added in excess. A sirupy solution of the corresponding ether of
orthosulpho-benzoic acid then remains. If, for instance, ethylalcohol is used,
ethylether is obtained, having the formula :-
This ether, and the analogues thereof, which form deliquescent liquids, are,
according to the researches of my foreign correspondents, profitably neutralised by
means of ammonia, sodium carbonate, or the like, and the solutions thus obtained
are subsequently evaporated.
The researches of my foreign correspondents have further shown, that the
remaining salt cakes, when heated with phosphorous oxychloride, or the like, yield
the chlorides of the corresponding ethers. Thus, for instance, the above mentioned

page_text: ethylether is converted into the chloride of orthosulpho benzoic ethylether having
the formula :-
If ammonia in excess is used during the latter process, the well-known sweet
compound termed "saccharin" is obtained, which separates in a pure state on
acidulating the solution thus formed.
The said ethylether of ortho sulphamine benzoic acid has been obtained in another
manner by Fahlberg and List, viz.: by treating saccharin with muriatic acid in the
presence of alcohol.
According to the researches of my foreign correspondents, the analogous
chlorides of other ethers of ortho sulpho benzoic acid are also, by a treatment
with ammonia, or the like, converted into the corresponding ethers of sulphamine-
benzoic acid, and subsequently into saccharin.
The processes hereinbefore defined may be carried out on a large scale, for the
purpose of producing saccharin commercially.
In view of other processes known for producing saccharin by means of ortho-
sulpho-benzoic acid, the new process hereinbefore defined constitutes a material
advantage, which becomes evident from the following
:-
1, The chlorides of the ethers of orthosulpho benzoic acid are readily formed,
even by means of phosphorous oxychloride, whilst the dichloride of ortho sulpho
benzoic acid hitherto used in the production of saccharin can be obtained but with
difficulty by means of phosphorous pentachloride, the employment of which, on a
large scale, is attended with considerable difficulty ;
2) The new process requires but a comparatively small quantity of phosphorous
oxychloride, for, on starting from the ortho-sulpho-benzoic acid, the hydroxy
group contained in the carboxylic group must also be displaced, though unprofitably,
by chlorine. Owing to this fact, two molecular proportions of phosphorous penta-
chloride and one molecular proportion of orthosulphobenzoic acid must be used
whereas but one half a molecular proportion of phosphorous oxy-chloride is
necessary in order to obtain the same result according to the new process herein-
before defined.
3) The chlorides of the ethers of orthosulphobenzoic acid are considerably more
stable than the said dichloride of orthosulphobenzoic acid, and therefore can be
readily converted into the ethers of orthosulphamine benzoic acid, and into
saccharin, by means of ammonia-water, whereas the dichloride of orthosulpho-
benzoic acid is only partially transformed into the sulphonic amide by means of
ammonia water, and therefore gaseous ammonia, or ammonium carbonate, are
necessary for this purpose.
.
In view of these considerable advantages, it is no matter, if the new process
starts from the ethers of orthosulphobenzoic acid; moreover, the materials used
for producing these ethers can, for the most part, be recovered..
The following example is given, in order to illustrate one method of practically
producing saccharin and certain intermediate products therefor, according to the
invention herein before defined. The parts are by weight.
.

page_text: 5 parts of the potassium salt of orthosulphobenzoic acid are finely mixed with
10 parts of ethylalcohol (containing 90 per cent. of pure ethylalcohol). Hydro-
chloric gas is then allowed to pass through the resulting liquid, until the latter
is saturated with this gas. The liquid is then allowed to stand during some time
at a somewhat higher temperature, and is filtered in order to remove the potassium
chloride, which is subsequently washed out with alcohol. The resulting filtrates
contain the readily soluble ethylether of ortho-sulpho-benzoic acid. The alcohol
and hydrochloric gas in excess are then distilled off, and the remaining residue is
carefully neutralised by means of potassium carbonate, or ammonia-liquor, and
then evaporated to dryness. 100 parts of the finely ground salt of the ethylether
of orthosulphobenzoic acid are mixed with 70 parts of phosphorous oxychloride,
and the resulting mixture is heated during some hours by means of a water-bath.
The liquid thus obtained, when cool, is stirred into ice-water, the chloride of the
The
ethylether of orthosulphobenzoic acid being separated as a pasty mass.
separated mass is introduced into ammonia water, which causes such a rise of the
temperature, that not only the formation of the ethylether of orthosulphamine,
benzoic acid takes place, but, at the same time, this ether is transformed by saponi-
fication into saccharin, owing to the violent action. The resulting solution is filtered,
in order to remove some insoluble by-products, and the filtrate thus obtained is
acidulated, the saccharin in a pure state being thereby separated.
In the production of saccharin and certain intermediate products therefor, my
foreign correspondents do not limit themselves to the particulars given in the
preceding example, as these can be varied.
Thus, for instance, the process can be carried out in such a manner that the
chloride of the ether of orthosulphobenzoic acid is converted merely into the ether
of orthosulphaminebenzoic acid, which will be the case, if the calculated quantity
of ammonia is used, and the action is allowed to proceed at low temperature. The
ether of orthosulphamine benzoic acid is then transformed into saccharin by a
separate suitable operation.
The process proceeds in a manner analogous to that described in the preceding
example, if other alkaline salts of orthosulphobenzoic acid are used in place of the
potassium salt employed in this example, or if the formation of the ether is
effected, say, by means of alkylhaloids, or if the analogous ethers are produced in
place of the ethylether of orthosulphobenzoic acid. Other phosphorous haloids can
be substituted for the phosphorous oxychloride used in the said example, and the
conversion of the chlorides of the ethers of orthosulphobenzoic acid into the
corresponding ethers of orthosulphaminebenzoic acid, and into saccharin, can also
be effected by using ammonium carbonate, or other suitable agents, in place of
ammonia prescribed in the said example.
Such or the like modifications do not alter the nature of this invention, which in
general relates to the conversion of the salts of orthosulphobenzoic acid into ethers
of orthosulphobenzoic acid, to the transformation of the latter ethers, or salts
thereof, into the chlorides of the corresponding ethers of orthosulphobenzoic acid,
and to the production of ethers of orthosulphaminebenzoic acid, and of saccharin,
from the said chlorides of ethers of the orthosulphobenzoic acid.
Dated this 11th day of March 1895.
NEWTON & SON,
Agents for the Applicant.

page_text: The Manufacture or Production of a Sweet Compound, and of
Certain Intermediate Products therefor.
I, HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, 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 foreign correspondents have found that the orthosulphobenzoic ethers can be
readily produced from the dipotassium salt, disodium salt, or the like, of ortho-
sulphobenzoic acid, and a molecular proportion of an alkylhaloid, or by heating
the mono- or dipotassium salt, or the like, of orthosulphobenzoic acid, with the
corresponding alcohols, in the presence of agents (such as muriatic acid, sulphuric
acid, or the like), capable of removing water. When heated with an alcohol, and
the latter or like agents, salts of orthosulphobenzoic acid, insoluble in alcohol,
become gradually dissolved, potassium chloride or the like being precipitated.
When the action is complete, the liquid is filtered, to remove the salt formed
during the operation, and the filtrate is treated in a suitable manner, in order to
remove the alcohol added in excess. A sirupy solution of the corresponding
orthosulphobenzoic acid ether then remains. If, for instance, ethyl alcohol is used,
the ethylether is obtained which is represented by the formula:-
This ether, and the analogues thereof, are advantageously neutralised with
ammonia, sodium carbonate, or the like, and the solutions thus obtained are
subsequently evaporated.
Instead of using alkaline salts of pure orthosulphobenzoic acid, mixtures
containing salts of ortho and parasulphobenzoic acid can also be taken. These
mixtures are first treated in the manner hereinbefore defined, for instance, with
alcohol, and muriatic acid, in order to effect the formation of the corresponding
ethers, and these are subsequently isolated, as above described in the case of
the pure orthosulphobenzoic ether. On evaporating the solutions containing the
admixed salts of the ortho- and parasulphobenzoic ethers, as the salts of the
parasulphobenzoic ethers dissolve with comparative difficulty, they separate first,
and can, for the most part, be removed by filtration or in any other suitable
manner.
The researches of my foreign correspondents have further shewn, that when the
salts obtained on evaporating the solutions of the salts of orthosulphobenzoic ether
are heated with phosphorus oxychloride, or the like, they yield the chlorides of the
corresponding ethers. Thus, for instance, the above mentioned ethylether is
converted into the chloride of orthosulphobenzoicethylether represented by the
formula:-

page_text: chloride is cautiously treated with ammonia water, or the like, it is transformed
into the orthosulphaminebenzoicethylether represented by the formula :-
whereas, when ammonia or the like is used in excess, and the action is allowed to
proceed more energetically, the well-known sweet compound termed "saccharin" is
obtained, which separates in a pure state on acidulating the solution ultimately
formed.
Naturally, the last-named operations, viz., the conversion of the salts of
sulphobenzoic ethers, first, into chlorides of sulphobenzoic ethers, subsequently into
sulphamine benzoic ethers, and finally into saccharin, can also be carried out with
mixtures containing salts of ortho and parasulphobenzoic ether. In this case, on
treating the mixtures of the chlorides with ammonia or the like, as the parasulph-
aminebenzoic ether is almost insoluble, it can be readily removed, for instance, by
filtration, the saccharin remaining dissolved in the filtrate, from which it can be
isolated in a pure state by subsequently acidulating and filtering off.
The said orthosulphamine benzoic ethylether has been obtained in another
manner by Fahlberg and List, viz., by treating saccharin with muriatic acid in
the presence of alcohol.
According to the researches of my foreign correspondents, the analogous
chlorides of other orthosulphobenzoic ethers are also converted, by treatment with
ammonia or the like, into the corresponding sulphamine benzoic ethers, and
subsequently into saccharin.
The processes herein before defined can be carried out on a large scale, for the
purpose of producing saccharin commercially.
In comparison with the other known processes for producing saccharin from
orthosulphobenzoic acid, the new process herein before defined offers material
advantages, as will be evident from the following:
:-
1. The chlorides of the orthosulphobenzoic ethers are readily formed, even by
means of phosphorus oxychloride, whilst the dichloride of orthosulphobenzoic acid,
which bas hitherto been used in the production of saccharin, can be obtained only
with difficulty by means of phosphorus pentachloride, the use of which, on a large
scale, is attended with considerable difficulty.
2. The new process requires the use of a comparatively small quantity of
phosphorus oxychloride. When using orthosulphobenzoic acid, the hydroxyl
group contained in the carboxyl group, must also be displaced, though unprofitably,
by chlorine, and, in consequence, two molecular proportions of phosphorus penta-
chloride, and one of orthosulphobenzoic acid, must be used, whereas but half a
molecular proportion of phosphorus oxychloride is required to produce the
equivalent quantity of saccharin, according to the new
process hereinbefore
defined.
3. The chlorides of the orthosulphobenzoic ethers are considerably more stable
than the said dichloride of orthosulphobenzoic acid, and therefore can be readily
converted into the orthosulphamine benzoic ethers, and into saccharin, by means
of ammonia-water, whereas the dichloride of orthosulphobenzoic acid is only
partially transformed into the sulphonic amide by means of ammonia water, and
therefore gaseous ammonia or ammonium carbonate is necessary for this purpose.
In view of these considerable advantages, it is immaterial that the new process
involves, in the first place, the use of ethers of orthosulphonic benzoic acid; more-
over, the materials used for producing these ethers can, for the most part, be
recovered.
:
The following example is given, in order to illustrate one method of practically
producing saccharin, and certain intermediate products therefor, according to the
invention hereinbefore defined. The parts are by weight.

page_text: EXAMPLE.
5 parts of the potassium salt of orthosulphobenzoic acid are thoroughly mixed
with 10 parts of ethylalcohol (containing 90 per cent. of pure ethylalcohol), and
hydrochloric gas is passed in, until the liquid is saturated with the. gas. The
mixture is then allowed to stand during some time, at a somewhat higher
temperature, and is then filtered, in order to remove the potassium chloride, which
is subsequently washed with alcohol. The filtrates contain the readily soluble
ethylether of orthosulphobenzoic acid. The alcohol and hydrochloric gas in
excess are then distilled off, and the residue is carefully neutralised with potassium
carbonate or ammonia liquor, and then evaporated to dryness. 100 parts of the
finely ground salt of the ethylether of orthosulphobenzoic acid are mixed with
70 parts of phosphorus oxychloride, and the mixture is heated during several hours.
by means of a water bath. When cool, the liquid product thus obtained is stirred
into ice water, which causes the separation of the chloride of the ethylether of
orthosulphobenzoic acid as a pasty mass. The separated chloride is then intro-
duced into ammonia-water, and this operation is attended with such a rise in
temperature, that not only is the ethylether of orthosulphamine benzoic acid
produced, but at the same time this ether is converted, by hydrolysis, into
saccharin. The solution is filtered in order to remove some insoluble bye-products,
and the filtrate thus obtained is acidulated, the saccharin in a pure state being
thereby separated.
In the production of saccharin and certain intermediate products therefor, my
foreign correspondents do not limit themselves to the particulars given in the
preceding example, as these can be varied.
Thus, for instance, the process can be carried out in such a manner, that the
chloride of the ether of orthosulphobenzoic acid is converted merely into the ether
of orthosulphaminebenzoic acid, which will be the case, if the calculated quantity
of ammonia is used, and the action is allowed to proceed at a low temperature.
The ether of orthosulphaminebenzoic acid is then transformed into saccharin by a
separate suitable operation, viz., by hydrolysis and acidulation.
The process proceeds in a manner analogons to that described in the preceding
example, if other alkaline salts of ortho-sulpho-benzoic acid are used, instead of
the potassium salt prescribed in this example, or if the formation of the ether is
effected, say, by means of alkylhaloids, or if the analogous ethers are produced in
place of the ethylether of ortho-sulpho-benzoic acid." Other phosphorus haloids
can be substituted for the phosphorus oxychloride used in the said example, and
the conversion of the chlorides of the ortho-sulpho-benzoic ethers into the corre-
sponding orthosulphamine benzoic ethers, and into saccharin, can also be effected
by using ammonium carbonate, or other suitable agents, in place of ammonia
prescribed in the said example.
Such or the like modifications do not alter the nature of this invention, which,
speaking generally, relates to the conversion of the salts of ortho-sulpho-benzoic
acid, into ortho-sulpho-benzoic ethers to; the transformation of the latter ethers,
or salts thereof, into the chlorides of the corresponding orthosulpho benzoic ethers;
and to the production of ortho-sulphamine-benzoic ethers, and of saccharin, from
the said ethers of the chlorides of ethers of the ortho-sulpho-benzoic acid.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
from abroad, I declare that what I claim is :-
1. The production of orthosulphobenzoic ethers represented generally by the
formula-

page_text: (R signifies here and hereinafter methyl, ethyl, or the like) from orthosulpho.
benzoic acid.
2. The process for producing the ortho-sulpho benzoic ethers hereinafter
defined, which process consists-(a) in treating a molecular proportion of the
dipotassium salt, or analogous alkaline salts, of orthosulphobenzoic acid, with a
molecular proportion of methyl haloid, ethyl haloid, or the like; or (b) in heating
the mono or dipotassium salt, or other alkaline salts, of orthosulphobenzoic acid,.
with methyl alcohol, ethyl alcohol, or the like, in the presence of dehydrating
agents, such as muriatic acid, sulphuric acid, or the like, and in subsequently
isolating the so-formed ortho-sulpho-benzoic ethers, either as such, or in the form.
of their alkaline or the like salts.
3. The conversion of the ortho-sulpho-benzoic ethers into chlorides of ortho-
sulpho-benzoic ethers, represented generally by the formula-
or into saccharin, respectively.
6. The manufacture of orthosulphamine benzoic ethers, by cautiously treating,.
at a low temperature, the chlorides of ortho-sulpho-benzoic ethers with ammonia,
ammonium carbonate, or the like agents, capable of introducing the amido group.
in place of the halogen atoms contained in the said chlorides of ortho-sulpho-
benzoic ethers.
7. The production of saccharin by an energetic treatment of the chlorides of
orthosulpho benzoic ethers with ammonia, ammonium carbonate, or the like, or
by hydrolysing the ortho-sulphamine-benzoic ethers with ammonia, alkalies, or the
like, and subsequently acidulating, in either case, the mixtures so formed.
8. The production of saccharin from ortho-sulpho-benzoic acid, ortho-sulpho-
benzoic ethers, chlorides of orthosulphobenzoic ethers, orthosulphamine benzoic
ethers, respectively, which processes consist in converting ortho-sulpho benzoic
acid into orthosulpho benzoic ethers, heating the alkaline salts of these ethers with
phosphorus oxychloride, phosphorus pentachloride, or the like to form chlorides of
sulphamine benzoic ethers, and transforming the latter chlorides, either first into.
ortho-sulphamine-benzoic ethers, and then into saccharin, or directly into.
saccharin.
NEWTON & SON,
Agents for the Applicant..