Improvements in the Manufacture of Ortho-chlor-benzaldehyde and its Separation from Orthc-nitro-benzaldehyde.
Year: 1898

page_text: Improvements in the Manufacture of Ortho-chlor-benzaldehyde and
its Separation from Orthc-nitro-benzaldehyde.
I, GEORGE WILLiam Johnson, of 47, Lincoln's Inn Fields, in the County of
London, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by Kalle & Co., of Biebrich-on-Rhine,
in the Empire of Germany,) to be as follows:-
In the Specification of Letters Patent No. 15179 of 1888 a process is described
for manufacturing ortho-nitrobenzaldehyde by oxidizing ortho-nitro-benzyl-
alcohol or ortho-nitro-benzylethers. My foreign correspondents have now found
that according to the same method the ortho-chlor-benzaldehyde can be pre-
pared from the corresponding ethers or from the corresponding alcohol.
The following Examples will make clear the nature of this invention which is
not limited to the details of these Examples.
EXAMPLE 1.
142 kilos. of ortho-chlor-benzylalcohol are heated and well agitated with
600 kilos. sulphuric acid of about 55° Bé. in a closed vessel provided with a lid.
to a temperature of about 40° Centigrade. 120 kilos. of a mixture of nitric and
sulphuric acids (containing 40 per cent. HNO3) are then slowly added. The
beginning of the oxydation is denoted by the appearance of red vapours escaping
by an outlet from the vessel. Excessively high temperature which might be
caused by the reaction can be avoided by cold water applied externally at intervals.
As soon as the escape of red nitrous gas ceases the mass is run into 600 litres of
cold water. The ortho-chlorbenzaldehyde formed separates from the acid liquid,
which is drawn off. In order to remove the last traces of acid the aldehyde is
washed with soda solution and subsequently with water. It is however not neces-
sary to start for the preparation of the ortho-chlorbenzaldehyde from the pure
isolated ethers, or from the ortho-chlor-benzylalcohol as the mixture of ortho-
chlor and ortho-nitro-benzylethers, or the mixture of the two substituted benzyl-
alcohols can be oxidized without previous separation. The mixture of ortho-
chlor- and ortho-nitrobenzaldehyde formed by the oxydation is separated by dis-
tillation with steam or by crystallization. The ortho- chlor-benzaldehyde is
liquid at ordinary temperatures and highly volatile with steam, whilst the ortho-
nitrobenzaldehyde is solid and scarcely volatile with steam.
EXAMPLE 2.
600 kilos. of chlorinated oil (containing about 40 per cent. of benzyl-chloride
derivatives) are boiled at the reflux cooler with 800 litres of dilute alcohol, 250 kilos.
of crystallized sodium acetate and 90 kilos. of soda ash, until the intermediately
formed ortho- nitro- and the ortho-chlorbenzylacetate are saponified. The alcohol
is now distilled off. On cooling a mixture of the corresponding substituted alcohols
crystallizes out from the reaction mass. It is however not necessary to wait for
this. After distilling off the alcohol the ortho-nitro-toluol is distilled over with

page_text: steam. The residue is diluted with water if necessary in order to keep the salts
(sodium acetate and sodium chloride) in solution. After cooling, the benzyl-
alcohol-derivatives become solid and are filtered off and pressed. 130 kilos. of
the press-cake are dissolved in 400 to 500 kilos. of sulphuric acid, of 50° to 60° Bé.,
at a temperature of about 40° Centigrade. 70 to 80 kilos. of a mixture of sul-
phuric and nitric acids (containing 38-39 per cent. HNO3), or a corresponding
quantity of nitric acid, or nitre, are now slowly added. The beginning of the
oxydation is indicated by the escape of nitrous gas and the end of the oxydation
by this escape ceasing. The temperature is best kept at 40° as long as the oxy-
dation lasts, cooling by water being resorted to if necessary. After the oxydation
is finished the mass is run into 500 litres of cold water. After allowing the mixture
to rest for a while the aldehydes are separated from the acid and the last traces
of acid are removed by washing with soda-solution. The remaining mixture of
the two aldehydes is then filtered and pressed. From the pressed off oil the ortho-
chlorbenzaldehyde can be obtained by fractional distillation with steam.
press cakes consist of ortho-nitrobenzaldehyde which is sufficiently pure for technical
purposes. The said cakes can however be purified by treatment with bisulphite
and by distillation with steam in order to remove the last traces of ortho-chlor-
benzaldehyde.
The
Instead of starting from a mixture of the two substituted benzylalcohols the
solution of the two alcohols obtained by extracting the product of reaction with
sulphuric acid directly, can be subjected to the oxydizing process.
It is not necessary to separate the mixture of ortho-chlor- and ortho-nitrobenzyl
derivatives from the unchanged ortho-nitrotoluol. Since the latter is much more
difficultly attacked by oxidizing agents, the mixture after distilling off the spirits,
may directly be subjected to the oxydizing process. The product of the oxydation
after being freed from acid in the manner described under the preceding Example 1,
is treated with a dilute sodium bisulphite solution. By this treatment the alde-
hydes are transferred, as bisulphite compounds, into the aqueous solution, and may
easily be separated from the nitrotoluol, which remains undissolved and retains
also the small amount of chlorinated bye-products formed in the chlorinating
process.
The aldehydes are precipitated from the aqueous bisulphite solution by adding
caustic soda lye and they are separated from each other by pressing the liquid
ortho-chlor-benzaldehyde off from the solid ortho-nitrobenzaldehyde, or by crystal-
lization, or by distillation with steam.
Dated this 17th dor of Mar 1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in the Manufacture of Ortho-chlor-benzaldehyde and
its Separation from Ortho-nitro-benzaldehyde.
I. GEORGE WILLIAM JOHNSON, of 47, Lincoln's Inn Fields, in the County of
London, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by Kalle & Co., of Biebrich-on-Rhine,
in the German Empire,) and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
In the Specification of Letters Patent No. 15179 of 1888 a process is described
for manufacturing ortho-nitro-benzaldehyde by oxidizing ortho-nitro-benzyl-
alcohol, or ortho-nitro-benzylethers. My foreign correspondents have found that,

page_text: according to the same method the ortho-chlor-benzaldehyde can be prepared
from the corresponding ethers or from the corresponding alcohol. The method
of preparing the ortho-chlorbenzylethers and the ortho-chlor-benzylalcohol is
described in my application for Letters Patent No. 11259 of 1898 of even date
with the present application.
The following examples will make clear the nature of this invention and the
manner in which it can be performed. The invention is not limited to the details
of these examples.
EXAMPLE I.
142 kilos, of ortho-chlor-benzylalcohol are heated, and well agitated with
600 kilos. sulphuric acid of about 55° Bé,. in a closed vessel provided with a lid,
to a temperature of about 40 degrees Centigrade. 120 kilos. of a mixture of nitric
and sulphuric acids (containing 40 per cent. HNO) are then slowly added. The
beginning of the oxidation is denoted by the appearance of red vapours escaping
by an outlet from the top of the vessel. Excessively high temperature, which
might be caused by the reaction can be avoided by cold water applied externally
at intervals. As soon as the escape of red nitrous gas ceases the mass is run into
600 litres of cold water. The ortho-chlor-benzaldehyde formed separates from
the acid liquid, which is drawn off. In order to remove the last traces of acid the
aldehyde is washed with soda solution and subsequently with water. The ortho-
chlorbenzaldehyde melts in pure state, not at 4.5 to 3 degrees Centigrade
(: H. Erdmann, Liebig's Annalen der Chemie 260, 56:) but as my foreign corre-
spondents have found, at +10.5 degrees Centigrade.
It is not necessary to start for the preparation of the ortho chlor-benzaldehyde
from the pure isolated ethers, or from the ortho-chlor-benzylalcohol, as the mixture
of ortho-chlor- and ortho-nitro-benzylethers or the mixture of the two substituted
benzylalcohols, obtained according to the process described in the Specification
of my aforesaid Application for Letters Patent No. 11259 of 1898 can be oxydised
without previous separation. The mixture of ortho-chlor and ortho-nitrobenzalde-
hyde formed by the oxidation is separated by distillation with steam or by crystal-
lization which consists in allowing the ortho-nitrobenzaldehyde to crystallize from
the mixture and by separating it from the oily part which contains the ortho-
chlor-benzaldehyde. The ortho-chlor-benzaldehyde is liquid, at ordinary tem-
peratures and highly volatile with steam, whilst the ortho-nitrobenzaldehyde is
solid and scarcely volatile with steam.
EXAMPLE II.
600 kilos. of chlorinated oil (containing about 40 per cent. of benzyl-chloride
derivatives) are boiled in a vessel provided with a reflux cooler with 800 litres of
dilute alcohol, 250 kilos. of crystallized sodium acetate and 90 kilos. of soda
ash, until the intermediately formed ortho nitro, and the ortho-chlor-
benzylacetate are saponified. The alcohol is now distilled off. On cooling, a
mixture of the corresponding substituted alcohols crystallizes out from the reaction
mass. It is however not necessary to wait for this. After distilling off the alcohol
the ortho-nitrotoluol is distilled over with steam. The residue is diluted with
water, if necessary, in order to keep the salts (sodium acetate and sodium chloride)
in solution. After cooling the benzyl-alcohol-derivatives become solid and arc
filtered off and pressed. 130 kilos. of the press-cake are dissolved in 400 to
500 kilos. of sulphuric acid of 50° to 60° Bé. at a temperature of about 40° Centi-
grade. 70 to 80 kilos. of a mixture of sulphuric and nitric acids (containing 38-
39 per cent. HNO3) or a corresponding quantity of nitric acid, or nitre are now
slowly added. The beginning of the oxidation is indicated by the escape of nitrous
gas and the end of the oxidation by this escape ceasing. The temperature is best
kept at 40° Centigrade as long as the oxidation lasts, cooling by water being
resorted to if necessary.
After the oxidation is finished the mass is run into 500
litres of cold water. After allowing the mixture to rest for a while the aldehydes
are separated from the acid and the last traces of acid are removed by washing with

page_text: soda solution. The remaining mixture of the two aldehydes is then filtered and
pressed. From the pressed off oil the ortho-chlor-benzaldehyde can be obtained
by fractional distillation with steam. The press-cakes consist of ortho-nitro-
benzaldehyde which is sufficiently pure for technical purposes. The said cakes
can however be purified by treatment with bisulphite and by distillation with steam
in order to remove the last traces of ortho-chlor-benzaldehyde.
Instead of starting from a mixture of the two substituted benzylalcohols the
solution of the two alcohols, obtained according to the process described in the
aforesaid Specification of my Application for Letters Patent No. 11259 of 1898,
by extracting the product of reaction with sulphuric acid directly, can be sub-
jected to the oxidizing process.
It is not necessary to separate the mixture of ortho-chlor-, and ortho-nitro-,
benzyl derivatives from the unchanged ortho-nitrotoluol. Since the latter is much
more difficultly attacked by oxidizing agents, the oil obtained according to the
process of the aforesaid Specification of my Application for Letters Patent
No. 11259 of 1898 after distilling off the spirits, may directly be subjected to the
oxidizing process. The product of the oxidation, after being freed from acid in
the manner described under the preceding Example 1, is treated with a dilute
sodium bisulphite solution. By this treatment the aldehydes are transferred, as
bisulphite compounds, into the aqueous solution, and may easily be separated
from the nitro-toluol, which remains undissolved and retains the chlorinated bye-
products formed in the chlorinating process.
The aldehydes are precipitated from the aqueous bisulphite solution by adding
caustic soda lye and they are separated from each other by pressing the liquid
ortho-chlor-benzaldehyde off from the solid ortho-nitro-benzaldehyde, or by
crystallization, or by distillation with steam.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The manufacture of ortho-chlor-benzaldehyde by oxidizing ortho-chlor-
benzylalcohol dissolved in sulphuric acid with oxidizing agents such as nitric acid.
2. The manufacture of ortho-chlor-benzaldehyde by oxidizing the mixture of
ortho-chlor and ortho-nitro-benzylethers, or of ortho-chlor, and ortho-nitro-
benzylalcohol obtained directly from the chlorination-product of ortho-nitro-
toluol and separating the ortho-chlor-benzaldehyde from the mixture with ortho-
nitrobenzaldehyde so obtained, by pressing, by distillation with steam, or by
crystallization in the manner described.
Tatl
1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.