Note: Descriptions are shown in the official language in which they were submitted.
1055519
The invention relates to a process for the manufacture
of butenediol diacetates, especially but-2-ene-1,4-diol diacetate
and but-l-ene-3,4-diol diacetate, by reaction of butadiene with
oxygen and acetic acid, in the gas phase or liquid phase, over
a solid catalyst which consists of platinum and an element
of main group 5 or 6.
According to German application DOS 2,217,452
published on October 26, 1972 in the name of Mitsubishi Chemical
butadiene can be reacted in the liquid phase with oxygen and
acetic acid, in the presence of solid catalysts containing
palladium to give butenediol diacetates. The reaction can also
be carried out in the gas phase over catalysts which contain
palladium and alkali metal salts as promoters (see German
application DOS 2,200,124 published on July 5, 1973 in the name
of Kuraray). A disadvantage of the liquid phase method is the low
rate of reaction. A disadvantage of the conventional gas phase
reaction is that undesired by-products such as l-acetoxy-1,3-
butadiene are formed, and that the reaction has to be carried
out at low butadiene concentrations so as not to reduce the
catalytic activity of the catalyst.
We have now found that butenediol diacetates, especially
but-2-ene-1,4-diol diacetate, are obtained in high yield and with
high space-time yield by reaction of butadiene, oxygen and acetic
acid, preferably in the gas phase, over a solid catalyst if the
catalyst
105~519
O.Z. 30,500
i8 platinum containing one or more elements of main group 5 or 6
selected from the group comprising phosphorus, arsenic, antimony,
bismuth, selenium and telluriumO
The catalyst is preferably a supported catalyst and may be
obtained by the conventional methods for producing supported
platinum catalysts.
The catalyst may be manufactured, eg~, by dispersing a
carrier in a solution obtained by dissolving a platinum compound
and one or more compounds of phosphurus, arsenic, antimony, bismuth,
tellurium and selenium in a suitable solvent, eg. water, then
evaporating off the solvent so as to deposit the above components
on the carrier and reducing the mass in a stream of gas containing
hydrogen or a reducing compound, or by means of conventional reducing
agents, such as hydrazine, methanol or formalin. The catalyst may
also be manufactured by adding a precipitant (eg. an alkaline
reagent) to a mixture of the carrier and the solution and then
carrying out a reduction by the above processO Platinum and antimony,
phosphorus, arsenic, bismuth, tellurium and selenium can in each
method be deposited on the carrier either simultaneously or succes-
sively; in some cases, the carrier can be added in the rorm of asoluble compound and then be co-precipitated with the active metal.
It is possible to use any reduction method by which platinum
and arsenic, antimony, bismuth, tellurium and/or selenium are
reduced to the metal state.
Carriers which may be used are active charcoal, silica gel,
silicic acid, alumina, clay, bauxite, magnesia, kieselguhr, pumice
and the like. The carriers may be activated by conventional methods,
eg. by treatment with acids.
The choice of the platinum compound used to manufacture the
catalyst is not a decisive ~actor though a halogen co~pound of
platinum, such as platinum-II chloride or platinum-IV chloride, a
salt o~ an organic acid, such as platinum acetate, platinum nitrate,
platinum oxide and the like are preferred for cost reasons. However,
other platinum compounds, eg. hexachloroplatinic acid or sodium
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- lOSSSl9 Z. 30,500
~tinosulrate can of course also bc used.
In general, the concentration of platinum on the carrier is
from 0.1 to 20% by weight~though higher and lower concentrations
are not excluded.
The arsenic, antimony, bismuth, tellurium and selenium com-
pounds used as the other components for the manufacture of the
catalyst are also not subject to special limitations; it is
possible to use the halides, nitrates, sulfates, oxides and other
compounds of this type. Suitable compounds containing phosphorus
are, inter alia, o- and m-phosphoric acid, alkali metal phosphates
and alkaline earth metal phosphates~
Though the amounts Or phosphorus, arsenic, antimony, bismuth,
tellurium and selenium compounds deposited on the carriers may
be varied within wide limits and still prove effective, amounts
of from 0.05 to 30~ by weight are generally appropriate.
Platinum catalyst of the above type which contain active
charcoal as the carrier and abou-t from 0.1 to 5% Or tellurium or
antimony in addition to from 0.1 to 10~ of platinum (based on the
total weight of catalyst) have proved exceptionally suitable and
are particularly preferred.
Higher concentrations of platinum than those stated can also
~e used but do not afford any economic advantage, since it was found
that the space-time yield and the olefin conversion do not increase
proportionately to the increase in concentration Or the metal.
The reaction which is to be catalyzed can be carried out by
any conventional process, continuously or batchwise, eg. using a
fixed bed, a fluidized bed or a three-phase fluidized bed, the chosen
state Or aggregation Or the reaction medium being the deciding factor.
The reactlon temperature in the gas phase is in general from
100 to 180C, preferably from 120 to 150C. The reaction pressure
is determined by the method used and is in general from atmospheric
pressure to about 100 bars.
In the liquid phase, the temperature is in general from 70 to
110~ and the pressure is in general again from 1 to 100 bars without
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A
1055519
being limited thereto since, eg., pressures of up to 1,000 bars
or more do not hinder the operation of the process.
The butenediol diesters which may be manufactured by the process
of the invention are valuable intermediates for, eg., the manufacture
of butenediol and butanediol. Butenediol 3,4-diacetate (vinylglycol
acetate), generally formed in minor amounts, is an intermediate
for the manufacture of vitamins and other biologically active
compounds.
EXAMPLE 1
25 mmoles (8.43 g) of platinum chloride and 25 mmoles of
tellurium oxide (3.99 g) are dissolved in 200 ml of 6N hydrochloric
acid; 50 g of active charcoal (0 1-0.4 mm particle diameter) which
has beforehand been boiled with 15% strength nitric acid, are
added and the mixture is slowly evaporated to dryness on a water-
bath. After additional drying, for which purpose a stream of nitrogen
at 150C is passed through the catalyst, in a tube, for 2 hours, the
material is reduced by saturating the stream of nitrogen with methanol
at room temperature and passing it over the catalyst at a rate of
5 l/min for 4 hours at 200C and 2 hours at 400C.
25 g of the catalyst thus produced and 540 g of acetic acid
are introduced into a stirred flask. A mixture of 3 l (~TP)/hr of
butadiene and 3 l (STP)/hr of oxygen is passed in at 85C and after
4 hours the reaction is discontinued, the catalyst is separated off,
the solution is concentrated and the residue is distilled. 36.8 g
Or diacetates are obtained, the butadiene conversion being 33%.
The distillate contains 81.2% of but-2-ene-1,4-diol diacetate and
18.8% of but-1-ene-3,4-diol diacetate.
EXAMPLE 2
250 mmoles (84.3 g) of platinum chloride and 32.5 mmoles
(5.2 g) of tellurium dioxide are dissolved in 2,000 ml of 6N hydro-
chloric acid, 500 g of active charcoal (particle diameter 4 mm) are
added and the mixture is slowly evaporated to dryness on a waterbath.
From then onward, the procedure described above is followed.
370 ml (144 g) of the catalyst obtained are introduced into a
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double-walled tube (32 mm diameter; L = 50 cm). 10.5 l (STP) of
butadiene, 10.5 l (STP) of oxygen and 250 g of acetic acid vapor
are introduced hourly at 130C. The vapor is at 130C.
Sample~ are taken hourly and fractionated by distillation.
Analysis Or the distillate shows that the proportion of butenediol
diacetate formed iB over 99% (based on the component present in
the lesser amount). The space-time yield after 4, 11 and 32 hours
are shown in the table.
time 4 11 32
g of BEDA/kg od catalyst x hr 43 43 42.5
g of BEDA/l of reaction space x hr 17 17 16.7
BEDA = but-2-ene-1,4-diol diacetate
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