IMPROVEMENTS IN THE MANUFACTURE OF BITTER ALMOND OIL, BENZOIC ACID, AND BENZOIC ETHERS, AND THE SIMULTANEOUS PRODUCTION OF CHLORIDES OF ORGANIC ACIDS
Year: 1880

page_text: LETTERS PATENT to Ferdinand August Zimmermann, of No. 21, Mincing Lane,
in the City of London, Merchant, for an Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF BITTER ALMOND OIL, BENZOIC ACID, AND BENZOIC
ETHERS, AND THE SIMULTANEOUS PRODUCTION OF CHLORIDES OF ORGANIC
ACIDS." A communication from abroad by Dr. Emil Jacobsen, of Berlin, in
the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said Ferdinand August Zim-
mermann at the Office of the Commissioners of Patents on the 12th July
1880.
.
FERDINAND AUGUST ZIMMERMANN, of No. 21, Mincing Lane, in the City of
London, Merchant. "IMPROVEMENTS IN THE MANUFACTURE OF BITTER ALMOND
OIL, BENZOIC ACID, AND BENZOIC ETHERS, AND THE SIMULTANEOUS PRODUCTION
OF CHLORIDES OF ORGANIC ACIDS." A communication from abroad by Dr. Emil
Jacobsen, of Berlin, in the Empire of Germany.
The formation from benzochlorides (benzodichloride and benzotrichloride) of
corresponding oxygen compounds (bitter almond oil and benzoic acid) has hitherto
required prolonged heating with alkalies, or with mineral acids, or with water at
high temperatures, and under more than ordinary pressure. Moreover, such
formation proceeds slowly and imperfectly. Such decompositions proceed quickly
however and at low temperatures, both with organic acids and analagous ethers
and alcohols, if a small quantity of certain metals or their salts employed, according
to my improved process of manufacture, as hereinafter described.
Again valuable and hitherto not easily obtainable organic bodies are formed by
my process as by-products. Without the employment of the metals and their salts,
above referred to and hereinafter more particularly mentioned, the desired con-
versions would not be effected even though considerably higher temperatures bo
employed.
In working my improved process I proceed as follows:-
One molecular weight of benzotrichloride is heated in a suitable closed vessel on
a water bath with a small proportion of chloride of
And with

page_text: weights of glacial acetic acid. Hydrochloric acid is then given off, and acetyl
chloride distills over, while benzoic acid remains behind with the unaltered chloride
of zinc. The products are the same whether the above method of admixture bo
followed or whether the trichloride be added to the acetic acid, or even though all
the ingredients be brought together simultaneously.
The following equation represents such reaction:-
benzoic acid,
C, H, CC, +2 CH, CO OH = C, H, CO OH + 2 CH, CO Cl + HCl.
Benzotrichloride, acetic acid,
acetyl, chloride,
Towards the end of the operation the heat is increased until the production of
hydrochloric acid (HCl) ceases, and any undecomposed acetic acid has been driven
off. The residue, generally a dark crystalline mass, if what is ordinarily known as
benzotrichloride has been used, is powdered and extracted by moderately warm
solution of soda. This solution will yield-white-crystals-of-benzoic acid._Com-
parative experiments have proved that the transformation of the benzotrichloride
is complete.
In order to prevent the production of hydrochloric acid in this reaction, the one
molecular weight of acetic acid may be displaced by an equivalent quantity of
anhydrous acetate of zinc.
Benzotrichloride also acts upon acetate of zinc, forming anhydrous aceto benzoic
acid and anhydrous acetic acid. This modification however is not recommended,
because the action of the large amount of chloride of zinc formed is nconveniently
energetic; moreover, benzoic acid would only be obtained with difficulty from the
anhydrous aceto benzoic acid. In reaction I, acetate of zine may be used instead of
chloride, as the former is not like the latter hygroscopic. Or metallic zinc and
oxide of zinc may be used, each of which dissolves in acetic acid, forming acetate of
zinc. We may even act upon benzotrichloride by chloride of zinc, which is in
process of formation.
Presence of water in the acetic acid diminishes the yield of acetyl chloride
because a portion of acetyl chloride as soon as formed is decomposd, hydrochloric
acid and acetic acid being regenerated. It is possible in this process to convert a
hydrated acetic acid into an absolute acid.
If the formation of acetyl chloride is not required, the transformation of benzo-
trichloride into benzoic acid being alone needed, a smaller quantity of chloride of zinc
and of acetic acid, etc., should be used; a condenser is provided for what acetyl chloride
may be formed. Enough water should then be dropped in to convert the benzo-
trichloride into benzoic acid. The greater portion of acetic acid used may then be
recovered. Solution of chloride of zinc alone will not act as a hydrating agent
upon benzotrichloride. Other organic carbon acids act like acetic acid upon benzo-
trichloride, as for instance formic acid, oxalic acid and others. Benzoic acid, taken
as the simplest type of an aromatic acid, acts thus upon benzotrichloride, forming
benzoyl chloride :-
CH, C Cl, + C, H, CO OH
Benzotrichloride
benzoic acid
=
2 C, H, CO Cl +
benzoylchloride.
HCl.
hydrochloride acid.

page_text: acetic acid, undergoes an analogous decomposition, forming bitter almond oil
(benzaldetryd), thus:-
C, H, CC, H + CH, CO OH = C, H, COH + CH, CO Cl + HCl.
Bonzodichloride, acetic acid, benzaldehyd, acctyl, chloride.
Benzadehyd itself reacts with benzotrichloride in presence of chloride of zinc.
If, therefore, acetic acid be added in process I to benzotrichloride containing some
benzodichloride, the benzoic acid obtained will smell of bitter almond oil, though
scarcely so if but littlo benzotrichloride is present. If much benzodichloride be
contained in the benzotrichloride the latter is not fit for the manufacture of benzoic
acid.
Benzotrichloride and benzodichloride also act upon the ethers corresponding
respectively to the organic acids, thus :—
C₁ H, CCI, + CH₂ CO OC₂ H₁ = C, H, CO CI + CH, CO CI + C₁₂ HCl.
benzotrichloride, ethylacetate benzoyl chloride, acetyl chloride, ethyl chloride.
C, H, CO CI + CH, CO OC, H₂ = C, H, CO OC₂ H¸ + CH, CO Cl.
Benzoyl chloride, ethyl acetate, ethel benzoate, acetyl chloride.
Ca H C C, H + CE, CO ỐC, H = C H COH + CH, CO CA + C, H, Cl.
Benzodichloride, ethyl acetate, benzaldehyd, acetyl chloride, ethyl chloride.
That is, benzoic ether (ethyl benzoate) or benzaldehyd, and the chlorides of the
alcohol radicals are obtained.
Benzotrichloride and benzodichloride act upon alcohol in presence of chloride
of zinc as follows:-
alcohol,
benzoylchloride,
C, H, C Cl, + C₂ H¸ОH = C H¸ CO Cl + C₂ H, Cl + HCl.
Benzotrichloride, alcohol,
ethyl, chloride.
C₁ H, CO Cl + C₂ H₂ OH = CH, CO OC, H, + HCI.
Bonzoylchloride,
ethyl benzoate, hydrochloric acid.
CH, CC, H + C₂H, OH = C₁ H₂ COH + C₂ H, Čl +
Benzodichloride, alcohol, benzaldehyd, ethyl chloride, hydrochloric acid.
The excess of alcohol and the hydrochloric acid will, in presence of chloride of
zinc, be converted into ethyl chloride.
HCI.
Other metallic salts, oxides of metals, and metals, act similarly, but that which I
find to oporate most advantageously are the before mentioned zinc salts.
In the above operations I make use of apparatus commonly used for chemical
operations of this kind. Glass, enamelled metal basins, and vessels not likely to be
affected by hydrochloric acid, or chlorides, or acetic acid may be used.

page_text: the said Ferdinand August Zimmermann in the Great Scal Patent Office on
the 12th January 1881.
FERDINAND AUGUST ZIMMERMANN, of No. 21, Mincing Lane, in the City of
London, Merchant. "IMPROVEMENTS IN THE MANUFACTURE OF BITTER ALMOND
OIL, BENZOIC ACID, AND BENZOIC ETHERS, AND THE SIMULTANEOUS PRODUCTION
OF CHLORIDES OF ORGANIC ACIDS." A communication from abroad by Dr. Emil
Jacobsen, of Berlin, in-the-Empire-of-Germany-
The formation from benzo-chlorides (benzodichloride and benzotrichloride) of
corresponding oxygen compounds (bitter almond oil and benzoic acid), has hitherto
required prolonged heating with alkalies, or with mineral acids, or with water at
high temperatures and under more than ordinary pressure. Moreover such formation
proceeds slowly and imperfectly.
By the use of the process hereinafter described, such decompositions are made to
proceed quickly and at low temperature both with organic acids and analogous
ethers and alcohols, by employing a small quantity of certain metals, or their salts,
according to my improved method of manufacture which I will proceed to describe.
It will be found further that valuable and hitherto not easily obtainable organic
bodies-are formed by my process us by-products. Without the employment of the
metals and their salts above referred to, and hereinafter moro particularly mentioned,
the desired conversions could only be effected at considerably higher temperatures
and then imperfectly.
In working my improved process I proceed as follows:-
One molecular weight of benzo-trichloride is heated in a suitable closed vessel on
a water bath with a small proportion of chloride of zinc, and with two molecular
weights of glacial acetic acid. Hydro chloric acid is then given off, and acctyl chlorido
distils over, while benzoic acid remains behind with the unaltered chloride of zinc.
The products are the same whether the above method of admixture be followed, or
whether the trichloride be added to the acetic acid, or even though all the ingredients
be brought together simultaneously.
The following equations represent such reaction :—
CH.CC+2 CH, CO OH = C, H, CO OH + 2 CH, CO CI + HCL.
Benzotrichloride, acetic acid, benzoic acid, acetyl chloride, hydrochloric acid.
Towards the end of the operation the heat is increased until the production of
hydro-chloric acid (HCI) ceases and any undecomposed acetic acid has been driven
off. The residue, generally a dark crystalline mass, if what is ordinarily known as
benzo-trichloride has been used, is powdered and extracted by means of a moderately
warm solution of soda. This solution will yield white crystals of benzoic acid.
Comparative experiments have proved that the transformation of the benzo-
trichloride is complete.
In order to prevent the production of hydrochloric acid in this reaction the one
molecular weight of acetic acid may be displaced by an equivalent quantity of
anhydrous acetate of zinc.
If acetate of zinc be employed the reaction will also take place, forming anhydrous
aceto, benzoic acid, and anhydrous acetic acid, without the production of hydro
chloric acid. This modification however is not recommended, because the action of
the large amount of chloride of zinc formed is inconveniently energetic. This
energetic action may however be considerably reduced, and the result will be as
above if another exsiccated acetic salt, such as acetate of soda, acetate of lime, or

page_text: Benzotrichloride and benzodichloride also acts upon the ethers, corresponding
respectively to the organic acids. Thus:-
CH, CC, + CH, CO OC, H₁
Benzotrichloride, ethyl acetate,
= C, H, CO Cl + CH, CO Cl + C₂ H, Cl.
benzoylchloride, acetyl chloride, ethyl chloride.
C H. CO C] + CH, CÓ OC, H = C, H, CO OC, H + CH, CÓ CI.
Benzoyl chloride, ethyl acetate,
ethyl benzoate, acetyl chloride.
C. H. CCl, H + CH. CÓ OC, H = C H COH + CH, CO CĨ + C, H, Cl.
Benzodichloride, ethyl acetate, benzaldehyd, acetyl chloride, ethyl chlorido.
That is, benzoic ether (ethyl benzoate) or benzaldehyd and the chlorides of
alcohol radicals are obtained.
Benzotrichloride and benzodichloride act upon alcohol in presence of chloride of
C₂ HC Cl₂ + С₂ H₂OH
-Benzotrichloride,
HCl.
= C. H. CO CI + C, H, Cl +
alcohol, benzoylchloride, ethylchloride, hydrochloric acid.
C, H, CO Cl + C₂ H₂ ОH = C₁ H, CO OC, H, + HCl.
Benzoylchloride, alcohol, ethyl benzoate, hydrochloric acid.
C, H, CC, H + C, H, OH = C, H, COH + C, H, Cl + HCI.
Benzodichloride, alcohol, benzaldehyd, ethyl chloride, hydrochloric acid.
The excess of alcohol and the hydrochloric acid will, in presence of chloride of
zinc, be converted into ethylchloride. The reactions herein described aro not
confined to the alcohols of the fatty-series, but apply also to the alcohols of the
aromatic series. Other metallic salts, oxides of metals and metals act similarly,
but those which I find to operato most advantageously are the before mentioned
zinc salts.
In the above operation, I make use of apparatus commonly used for chemical.
operations of this kind, as will be well understood by persons experienced in
carrying out chemical operations, such as are herein referred to. Glass, enamelled
metal basins, and vessels not likely to be affected by hydrochloric acid or chlorides
or acetic acids, may be used.
Having now described the nature of the said Invention, and in what manner the
same is to be performed, I declare that I claim the manufacture of products, such as
bitter almond oil, benzoic acid, cinnamic acid, and benzoic ether, and also the
simultaneous production of chlorides of organic acids, such as are hereinbefore
referred to, by means of the improved processes employed, substantially as abovo
respectively described.
In witness whereof, I, the said Ferdinand August Zimmermann, havo hereunto
set my hand and seal, this Eleventh day of January, in the year of our
Lord One thousand eight hundred and eighty one.
Signed, sealed, and delivered by
the within named Ferdinand
August Zimmermann, in the
presence of
E. HERBERT ARMITAGE,
F. A. ZIMMERMANN. (L.S.)
Clerk to Messrs. Van Sandau & Cumming,
13, King St., Cheapside.