LIQUID-PHASE PREPARATION OF DELTA-KETO CARBOXYLIC ACID ESTERS UTILIZING LIQUID-PHASE INSOLUBLE CATALYST

PREPARATION EN PHASE LIQUIDE D'ESTERS D'ACIDE DELTA-CETO-CARBOXYLIQUE, A L'AIDE D'UN CATALYSEUR INSOLUBLE EN PHASE LIQUIDE

English Abstract

LIQUID-PHASE PREPARATION OF DELTA-KETO CARBOXYLIC ACID ESTERS
UTILIZING LIQUID-PHASE INSOLUBLE CATALYST
Abstract
A process is disclosed for making a delta-keto carboxylic acid ester
by the addition reaction of a ketone and an acrylic acid ester in the presence ¦
of a catalyst provided by a mixture of a primary amine component and a water-
promoted catalytic material component. The water-promoted catalytic material
component, which is substantially or entirely insoluble in the reaction
medium, is selected from the group of materials consisting of an alkali half-
salt of phthalic acid, an aluminum hydrosilicate mineral, a silica-alumina
molecular-sieve zeolite, a silica-free alumina and a sulfonated perfluorinated
resin. The process is particularly suitable for making methyl 4-oxocaproate
from the addition reaction of acetone and methyl acrylate.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE
IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for making a delta-keto carboxylic acid ester having
the general formula
<IMG>
wherein R may be a benzyl group or an alkyl group of one to about six carbon
atoms, wherein R' may be selected from hydrogen, methyl, ethyl, propyl and
isopropyl groups, and wherein R" may be an alkyl group of one to about 24
carbon atoms, the process comprising:
forming a reaction medium for reacting a ketone having an
alpha-position active hydrogen with an acrylic acid ester
having the general formula
<IMG>
wherein each R, R' and R" is as defined before, said
reaction medium containing water and an effective amount
of a catalyst, the catalyst provided by a mixture of a
primary amine component and a water-promoted catalytic
material component which is substantially insoluble
in the reaction medium, the water-promoted catalytic
material component selected from the group consisting
of an alkali half-salt of phthalic acid, an aluminum
hydrosilicate mineral, a silica alumina molecular-sieve
zeolite, a silica-free alumina and a sulfonated
perfluorinated resin;
whereby a reaction product mixture may be formed containing
delta-keto carboxylic acid ester in contact with the selected
substantially insoluble catalytic material component, which
component may be removed substantially entirely from
- 13 -

the reaction product mixture prior to distillation to obtain high purity
delta-keto carboxylic acid ester.
2. The process of Claim 1 wherein said water-promoted catalytic
material component is an alkali half-salt of phthalic acid, the process fur-
ther comprising a second step of
forming a distillate residue substantially devoid of water
by distilling the reaction product of said first step, said
distillate residue consisting of a liquid portion in contact
with a solid material containing the alkali half-salt of
phthalic acid, the liquid portion containing delta-keto
carboxylic acid ester;
whereby the liquid portion may be separated from the solid material, the
liquid portion then treated to recover delta-keto carboxylic acid ester rela-
tively free of by-products, the solid material then treated to recover the
alkali half-salt of phthalic acid for re-use as the catalytic material.
3. The process of Claim 2 wherein said alkali half-salt of phthalic
acid is sodium hydrogen phthalate.
4. The process of Claim 2 wherein said alkali half-salt of phthalic
acid is potassium hydrogen phthalate.
5. The process of Claim 2 wherein said acrylic acid ester is methyl
acrylate, said ketone is acetone, said delta-keto carboxylic acid ester is
- 14 -

methyl-4-oxocaproate, and said alkali half-salt of phthalic acid is either
potassium hydrogen phthalate, or sodium hydrogen phthalate, or a mixture of
both.
6. The process of Claim 1 wherein said water-promoted catalytic
material component which is insoluble in the reaction medium is selected from
the group consisting of an aluminum hydrosilicate mineral, a silica-alumina
molecular-sieve zeolite, a silica-free alumina and a sulfonated perfluorinated
resin, the process further comprising a second step of
filtering the selected insoluble catalytic material compo-
nent from the reaction product mixture, so that the reaction
product mixture may be distilled in the substantial absence
of the catalytic material component to obtain high purity
delta-keto carboxylic acid ester.
7. The process of Claim 6 wherein said water-promoted catalytic
material component is an aluminum hydrosilicate.
8. The process of Claim 6 wherein said water-promoted catalytic
material component is a silica-alumina molecular-sieve zeolite.
9. The process of Claim 6 wherein said water-promoted catalytic
material component is a silica-free alumina.
- 15 -

10. The process of Claim 6 wherein said water-promoted catalytic
material component is a sulfonated perfluorinated resin.
11. A process for making methyl 4-oxocaproate, comprising:
(a) reacting methyl acrylate with acetone in a reaction medium
containing water and a catalyst to make a reaction product
mixture containing methyl 4-oxocaproate, said catalyst
provided by a mixture of a primary amine and potassium
hydrogen phthalate, the water being present in an amount at
least sufficient to act as a promoter for said catalyst but
in an insufficient amount to dissolve a significant portion
of the potassium hydrogen phthalate,
(b) distilling the reaction product mixture of step (a) to form
a distillate residue containing methyl 4-oxocaproate and
potassium hydrogen phthalate, said distillate residue sub-
stantially devoid of water;
(c) treating said distillate residue to remove potassium
hydrogen phthalate from the residue and thereby provide a
remainder of the distillate residue containing methyl
4-oxocaproate;
whereby the remainder of the distillate residue may be treated by distillation
to provide purified methyl 4-oxocaproate substantially devoid of by-products.
12. The process of Claim 11 wherein said potassium hydrogen
phthalate is initially present in the reaction medium in an amount from about
0.07 to about 0.13 parts potassium hydrogen phthalate to one part of methyl
acrylate.
- 16 -

13. The process of Claim 12 wherein said water is initially present
in the reaction medium in an amount from about one to about five parts of
water to one part of potassium hydrogen phthalate.
14. A process for making methyl 4-oxocaproate, comprising:
(a) reacting methyl acrylate with acetone in a reaction medium
containing water and a catalyst to make a reaction product
mixture containing methyl 4-oxocaproate, said catalyst pro-
vided by a mixture of a primary amine and an aluminum
hydrosilicate mineral, the water being present in an amount
at least sufficient to act as a promoter for said catalyst;
(b) filtering the reaction product mixture of step (a) to
remove said aluminum hydrosilicate mineral which is
insoluble in the reaction product mixture, to provide a
filtrate which is free of said alumnum hydrosilicate
mineral;
(c) distilling the filtrate of step (b) to obtain high purity
methyl 4-oxocaproate.
15. The process of Claim 14 wherein said aluminum hydrosilicate
mineral is initially present in the reaction medium in an amount in a range
from about 0.1 to about 4 parts aluminum hydrosilicate mineral to one part
methyl acrylate starting material.
- 17 -

16. The process of claim 14 wherein step (a) is accomplished by
passing methyl acrylate and acetone continuously through a fixed bed com-
prising said aluminum hydrosilicate material.
17. A process for making methyl 4-oxocaproate, comprising:
(a) reacting methyl acrylate with acetone in a reaction medium
containing water and a catalyst to make a reaction product
mixture containing methyl 4-oxocaproate, said catalyst
provided by a mixture of a primary amine and a silica-
alumina molecular sieve zeolite, the water being present in
an amount at least sufficient to act as a promoter for said
catalyst;
(b) filtering the reaction product mixture of step (a) to
remove said silica-alumina molecular-sieve zeolite which is
insoluble in the reaction product mixture, to provide a
filtrate which is free of said silica-alumina molecular-
sieve zeolite,
(c) distilling the filtrate of step (b) to obtain high purity
methyl 4-oxocaproate
18. The process of Claim 17 wherein said silica-alumina molecular-
sieve zeolite is initially present in the reaction medium in an amount in a
range from about 0.1 to about 4 parts silica-alumina molecular-sieve zeolite
to one part methyl acrylate starting material.
- 18 -

19. The process of Claim 18 wherein step (a) is accomplished by
passing methyl acrylate and acetone continuously through a fixed bed compris-
ing said silica-alumina molecular-sieve zeolite.
20. A process for making methyl 4-oxocaprodte, comprising:
(a) reacting methyl acrylate with acetone in a reaction medium
containing water and a catalyst to make a reaction product
mixture containing methyl 4-oxocaproate, said catalyst
provided by a mixture of a primary amine and a silica-free
alumina the water being present in an amount at least
sufficient to act as a promoter for said catalyst;
(b) filtering the reaction product mixture of step (a) to
remove said alumina which is insoluble in the reaction
product mixture, to provide a filtrate which is free of
said alumina;
(c) distilling the filtrate of step (b) to obtain high purity
methyl 4-oxocaproate.
21. The process of Claim 20 wherein said alumina is initially
present in the reaction medium in an amount in a range from about 0.1 to about
4 parts alumina to one part methyl acrylate starting material.
22. The process of Claim 20 wherein step (a) is accomplished by
passing methyl acrylate and acetone continuously through a fixed bed compris-
ing said alumina.
- 19 -

23. A process for making methyl 4-oxocaproate, comprising:
(a) reacting methyl acrylate with acetone in a reaction medium
containing water and a catalyst to make a reaction product
mixture containing methyl 4-oxocaproate, said catalyst
provided by a mixture of a primary amine and a sulfonated
perfluorinated resin, the water being present in an amount
at least sufficient to act as a promoter for said catalyst;
(b) filtering the reaction product mixture of step (a) to
remove said sulfonated perfluorinated resin which is
insoluble in the reaction product mixture, to provide a
filtrate which is free of said sulfonated perfluorinated
resin;
(c) distilling the filtrate of step (b) to obtain high purity
methyl 4-oxocaproate.
24. The process of Claim 23 wherein said sulfonated perfluorinated
resin is initially present in the reaction medium in an amount in a range from
about 0.001 to about 0.04 parts sulfonated perfluorinated resin to one part
methyl acrylate starting material.
25. The process of Claim 24 wherein step (a) is accomplished by
passing methyl acrylate and acetone continuously through a fixed bed compris-
ing said sulfonated perfluorinated resin.
-20-

Description

~21Z382
LIQUID-PHASE PREPARATION OF DELTA-KETO CARBOXYLIC ACID ESTERS
¦UTILIZING LIQUID-PHASE INSOLUBLE CATALYST
8ackground of the Invention
l Field o the Invention
¦Preparation of delta-keto carboxylic acid esters by the Michael reac- !
¦ tion of a ketone with an acrylic acid ester is well known. Of particular
interest herein are improved catalysts for the reaction.
State of the Art
l An alkaline-catalyzed Michael reaction of a ketone with an acrylic
¦ acid ester to provide a delta-keto carboxylic acid ester is described in
¦ Comptes Rendus~ 248, 1533-1535 ~1959). An alkaline catalyst as provided by
sodium amide or potassium ethylate is used, which catalyst is soluble in the
reaction medium and is reactive with the keto-ester reaction product. Hence,
¦ low yields are reported for most ketone starting materials.
¦ Similar addition reactions have been reported with the use of cata-
¦ lysts which are soluble in the reaction media. For example, in U.K. Patent
¦ No. 1,389,510 to Stamicarbon B.V., there is disclosed a catalyzed Michael
¦ reaction of a ketone with an acrylic acid ester to provide a delta-keto
¦ carboxylic acid ester. The reaction is catalyzed by a mixture of a primary
¦ amine and one of several types of acidic compounds, all of which are soluble
¦ in the reaction medium. In U.K. Patent No. 1,473 184 to Hoechst, there is
I described a similar Michael addition reaction for making 5-oxo-carboxylic acid
esters (i.e., delta-keto esters) by reacting a ketone with a-n acrylic acid
I ester in the presence of a mixture of a primary amine and one of several
¦ acids, all being soluble in the reaction medium. Each of these acid-catalyzeld
¦ reactions is disadvantageous in that the acidic compound of the catalyst,

121Z382
being soluble in the reaction medium, is difficult to separate from delta-~e~
¦ ester reaction product. Hence, in purification of the reaction product, such
¦ as by distillation, the combination of heat and the acidic catalyst typically
¦ causes formation of undesirable by-products and consequently lower yields of
delta-keto ester.
¦ There is need, therefore, for a process for making delta-keto carbox-¦ ylic acid ester in which high yields of pure product are obtained.
Summary of the Invention
A process is provided for making in a single pass a high yield of a
delta-keto carboxylic acid ester in a liquid phase, the delta-keto ester hav-
ing the general formula
R - C - C - C - C - C - 0 - R" (I)
wherein R may be a benzyl group or an alkyl group of one to about six carbon
atoms, R' may be selected from hydrogen, methyl, ethyl, propyl and isopropyl
groups, and R" may be an alkyl group of one to abut 24 carbon atoms. A first
step of the process involves forming a reaction medium for reacting a ketone
having an alpha-position active hydrogen with an acrylic acid ester having the
general formula
R' 0
CH2 = - C - 0 - R" (II)
R'
wherein each R, R' and R" is as defined before, the reaction medium containing
water and an effective amount of a catalyst. The catalyst is provided by a
mixture of a primary amine ccmponent and a water-promoted catalytic material
component selected from the group consisting of an alkali half-salt of
phthalic acid, an aluminum hydrosilicate mineral, a silica-alumina molecular
sieve, a silica-free alumina and a sulfonated perfluorinated resin. These
z

3LZ~Z38~
s
catalytic materials are characterized in being insoluble, either entirely or
substantially entirély, in the reaction medium.
The reaction product mixture contains delta-keto carboxylic acid
ester in contact with the catalytic material which is insoluble in the liquid
phase of the reaction mixture. Removal of the insoluble catalytic material
and subsequent distillation of the reaction product mixture provides a high
purity delta-keto carboxylic acid ester in the distillate not contaminated
with by-products generated during distillation because of the presence of
residual catalyst from the addition reaction.
lo The process is particularly suitable for making methyl 4-oxocaproate
by the addition reaction of methyl acrylate and acetone in the presence of any
member of the specified family of catalyst material.
One advantage of the process of the invention is that because the
catalyst is substantially or entirely insoluble in the reaction medium, there
can be obtained a reaction product free of the catalyst. Hence, during dis-
tillation of the reaction product to obtain pure delta-keto ester, there are
relatively less harmful by-products formed as compared to prior art processes
in which distillation occurs in the presence of acid catalyst.
A second advantage resides in selected preferred species of the
family of catalyst materials being suitable for use in a fixed bed reactor,
inasmuch as the selected catalyst is insoluble in the reaction medium. Hence,
the addition reaction may be carried on continuously.
Detailed Description of the Invention
In forming a reaction medium for preparation of a delta-keto carbox-
ylic acid ester, active ketone and acrylic acid ester startin materials of the
type generally defined are placed in a stainless-steel, stirred, pressure
reactor. The ketone serves both as a reactant and as a reaction medium.
- 3 -

~Z1238~ ;
Hence, the ketone is usually present in an amount in molar excess of th2
acrylic acid ester in a range from about 7:1 to about 15:1.
Suitable ketones have active or labile hydrogen on an alpha-carbon
relative to the carbonyl of the ketone. Such ketones include acetone, methyl
ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isopropyl ketone,
cyclopentanone, cyclohexanone, 2-methylcyclohexanone and 4-methylcyclohexa- ¦none. Suitable acrylic acid esters within general formula II are OC,~ -unsat- ¦urated carboxylic acid esters, such as methyl acrylate, ethyl acrylate methyl
methacrylate, ethyl methacrylate, methyl crotonate, ethyl crotonate, methyl
lo maleate, ethyl maleate) methyl fumarate and ethyl fumarate.
The addition reaction goes forward in the presence of a co-catalyst
combination provided by an amine and an water-promoted catalytic material.
Suitable amines include methyl amine, ethyl amine, n-propyl amine, isopropyl
amine, n-butyl amine, isobutyl amine, sec butyl amine, sec-pentyl amine, hexyl
amine, cyclopentyl amine, cyclohexyl amine and hexamethylenediamine, General-
ly, the amount of amine present in the reaction mixture is in a range from
about 0.05 to about 0,5 mole per mole of acrylic acid ester starting material
initially present in the reaction mixture.
Examplei of alkali half-salts of phthalic acid suitable as catalytic
materials include lithium hydrogen phthalate, sodium hydrogen phthalate and
potassium hydrogen phthalate. A preferred alkali half-salt of phthalic acid
is potassium hydrogen phthalate. These half-salts are substantially, but not
entirely, insoluble in water. Thus when one of these half-salts is used as a
catalytic material, the amount of water present in the reaction mixture will
be that amount required to promote the half-salt catalytic material, but in an
amount insufficient to dissolve a significant portion of the half-salt. The
term "significant portion" means that amount of half-salt which, when present
during distillation of the reaction product mixture, does not promote the
formation of harmful by-products. enerdlly, a proper amount of water for

lZ~Z3~2
promotion of the half-salt, but which is insuFficient for dissolving a sig-
nificant portion of the half-salt, is in a range from about one to about five
parts of water per part of half-salt in the entire reaction mixture. Typical- ¦
ly, an alkali half-salt of phthalic acid may be used as a catalytic material
in an amount in a range from about 0.02 to about 0.13 part half-salt to one
part acrylic acid ester start;ng material initially in the reaction mixture.
A second suitable catalytic material is provided by an aluminum
hydrosilicate mineral. Such material is characterized by the ideal formula
M2o3-4sio2-H2o + H20 (III)
and is generally known as Montmorillonite. Suitable Mortmorillonite catalytic
materials are sold ccmmercially under the trademark "K-Catalysts" by Sud-
Chemie A.G., Munchen, W. Germany. These clay-like materials are characterized
in belonging to the group of 3-layer minerals, in having a large number of
exchangeable ions, and in being virtually insoluble in water. Generally, the
aluminum hydrosilicate material may be present in an amount in a range from
about 0.1 to about 4 parts by weight of aluminum hydrosilicate to one part
; acrylic acid ester starting material initially in the reaction mixture.
A third type of catalytic material is provided by a silica-alumina
molecular sieve zeolite in which the atomic ratio of silicon to aluminum is
about 10 to one. Typically useful materials are characterized in having a
surface area in a range from about 450 Jo about 500 m2tg, a water content in a
range from about 11 to 15 weight percent. The material is virtually insoluble
in water. Particularly suitable materials are sold commercially under the
trademark "hydrogen mordenite", Strem Chemicals, Inc., Newburyport, Mass.
Generally, the silica-alumina zeolite may be present in an amount in a range
from abour 0.1 to about 4 parts by weight silica-alumina zeolite to one part
acrylic acid ester starting material initially present in the reaction
mixture.

2382
A fourth type of catalytic material is provided by a silica-free
alumina which is characterized in being virtually insoluble in water. Suit-
able silica-free A1203 catalytic material is sold under the trademarX
HA 100 S by Houdry Process and Chemical Co., Div. of Air Products and Chemical
Co., Inc., Philadelphia, Pa. Generally, the silica-free alumina catalytic
material may be present in an amourlt in a range from about 0.1 to about 4
parts by weight alumina to one part acrylic acid ester starting material
initially present in the reaction mixture.
A fifth type of catalytic material is provided by a sulfonated per-
fluorinated resin prepared from copolymers of tetrafluoroethylene and monomers
such as perfluoro-3-6-dioxa-4-methyl-7-octane sulfonyl fluoride. The resin is
; virtually insoluble in water. Suitable resins are sold under the trademark
NAFION~ 501 by DuPont Company, Wilmington, Del. Generally, the sulfonated
perfluorinated resin may be present in an amount in a range from about 0.001
to about 0.04 parts resin to one part acrylic acid ester starting material
initially present in the reaction mixture.
For an addition reaction in which any of the second through fifth
catalytic materials is used, there must be an amount of water present in the
reaction mixture sufficient to promote activity of the catalytic material.
Inasmuch as none of these specified catalytic materials is soluble to any
detectable extent in any amount of water, the amount of water to be used may
be determined primarily by the amount of acrylic acid ester starting materi-
als. Thus excess amounts of water play no part in formation of harmful by-
products in the reaction product mixture. Generally, the amount of water used
will be for any of the second through fifth described catalytic materials in
an amount in a range from about 0.02 to about 0.12 part by weight catalytic
ma teri al to one ca rt ac ryl i c dC id ester start i ng ma ter i al .
- 6 -
.

121Z38Z
In providing the catalyst for a reaction mixture, the amine component
¦ and the catalytic material component may be added separately or as a mixture I¦ of the two components.
Before distillation at temperatures high enough for recovery of a
fraction of pure delta-keto carboxylic acid ester, the insoluble or substan-
tially insoluble catalytic material must be removed from contact with the
liquid phase containing delta-keto carboxylic acid ester. In reactions
utilizing an alkali half-salt of phthalic acid as the catalytic material
component, a preliminary distillation must be performed at about 105C in
order to remove any water from the reaction product mixture. Once the reac-
tion product mixture is devoid of water, the alkali half-salt of phthalic acid
becomes virtually insoluble in the reaction product mixture and may be removed
by filtration. For the second through fifth members of the family of cata-
lytic materials, there is no need for a preliminary distillation step because
; such materials are easily filtrable from the reaction product mixture in view
of their insolubility in the mixture irrespective of the amount of water
present. A filtrate obtained from either of these reaction mixtures may then
be subjected to fractional distillation under reduced pressure to recover a
fraction containing delta-keto carboxylic acid ester of high purity.
The following examples set forth specific embodiments of the inven-
tion. The invention is not to be construed, however, as being limited to
these embodiments for there are, of course, numerous possible variations and
modifications. All parts and percentages of the examples as well as through-
out the specification are by weight unless otherwise indicated.
Example I
In a stainless-steel, mechanically stirred pressure reactor equipped
with temperature sensing and control means, there were charged 1660 9 acetone,
215 9 methyl acrylate, 22 9 isopropylamine, 2 9 hydroquinone, 10 9 potassium
,.. ... ... _ I._

~%~ Z38Z
acid phthalate and 18 9 of water. the reactor headspace was purged with
nitrogen so as to eliminate substantially any ambient oxygen in the reactor.
Then the reaction mixture was heated with agitation to a temperature of 1~3- !,
185C and maintained under these conditions for about six hours. A pressure
of 300 p.s.i.g. was observed after the reaction temperature was reached.
After the reaction vessel cooled to room temperature, the entire contents of .
the reaction mixture were transferred to a distillation apparatus. Then
unreacted acetone, methyl acrylate, isopropylamine and water were separated as
distillate, with a distillation temperature maintained at a maximum of about
105C. The residual material in the distillation apparatus was transferred to
a filtration apparatus Inasmuch as the potassium acid phthalate was substan-
tially insoluble in the liquid reaction product, there was substantially
complete separation of the potassium acid phthalate from the liquid filtrate
which contained crude methyl 4-oxocaproate (MOC) product. The crude MOC was
passed through a bed of sodium bisulfate to remove residual basic material,
such as ;sopropyl amine, from the MOC product. Then the MOC product was
placid in a distillation apparatus and recovered as a distillate at 120-124C
distillation temperature under about 40 mm pressure absolute. Purified MOC in
an amount of 328 9 was recovered which corresponds to a yield 91 mole percent
based on methyl acrylate starting material. A distillation residue of 14 9
was obtained Gas chromatographic analysis ox the MOC product showed a purity
of MOC in excess of 99.5 percent. A trace impurity was identified as phorone.
Example II
An addition reaction was run with the equipment, starting materials,
and in accordance with the procedures as generally described in Example I. In
order to show the rate of conversion of starting reactants to methyl 4-oxo-
caproate, samples of the reaction medium were taken during a Pive hour reac-
- 8 -

lZlZ382
tion period. Table I lists methyl acrylate conversions and yields of mef~1
4-oxocaproate for each of the samples. -i
Table I
Reaction of Acetone and Methyl Acrylate
to Form Methyl 4-Oxocaproate Over Five Hour Reaction Period
% Yield Per Pass % Ultimate Yield
Reaction Methyl Acrylate of Methyl of Methyl
Time (hrs.) Conversion_(%) 4-Oxocaproate (%) 4-oxocaproate (%)
..
2 79 70 89
3 88 79 89
4 94 86 91
97 90 93
Example III
An addition reaction was run with the equipment, starting reactants,
and in accordance with the procedures as generally described in Example I. In
order to demonstrate the promoting effect of water or the water-promoted
catalytic material as provided by 4.0 9 potassium hydrogen phthalate per mole
of methyl acrylate starting reactant, two side-by-side reactions were run
differing only by the presence or absence of water. In reaction (a), 7.2 9
water per mole of methyl acrylate was used. In reaction (b), no water was
added. Results are summarized in Table II.
Example IV
An addition reactor was run with the equipment, starting reactants,
and in accordance with the procedures as generally described in Example I. In
order to demonstrate the promoting effect of plater on the water-promoted cata-
lytic material as provided by 40 9 montmorillonite (K-306, Sud Chemie A.G.)
catalytic material was used per mole methyl acrylate starting reactant, two
side-by-side reactions were run differing only by the presence or absence of
_ g _

lZ1238Z -,
water. In reaction (a), 7.2 9 water per mole of methyl acrylate ~,~s used. In
reaction (b), no water was added. Results are summarized in Table II.
¦ Example V
An addition reaction was run with the equipment starting reactants,
¦ and in accordance with the procedures as generally described in Example I. In¦ order to demonstrate the promoting effect of water on the water-promoted cata-¦ lytic meterial as provided by 60 g silica-free alumina (HA-1005, Houdry Proc.
¦ & Chem. Co.) catalytic material was used per mole methyl acrylate starting
¦ reactant, two side-by-side reactions were run differing only by the amount of
¦ water present. In reaction (a), 7.2 g water per mole of methyl acrylate us
¦ used. In reaction (b), 2.0 9 water was used per mole of methyl acrylate.
Results are summarized in Table II.
Example VI
An addition reaction was run with the equipment, starting reactants
and in acco~ance with the procedures as generally described in Example I,
except that 40 9 silica-alumina molecular sieve zeolite catalytic material
("hydrogen Mordenite", Strum Chem., Inc.) was used per mole of methyl acrylate
starting reactant Results are summarized in Table II.
Example VII
An addition reaction was run with the equipment, starting reactants
and in accordance with the procedures as generally described in Example I,
except that 0.4 g sulfonated perfluorinated resin (NAFION~ 501, DuPont Co.)
was used per mole of methyl acrylate starting reactant. Results are summa-
rized in Table II.
Il
- 10

lZ123~Z
Table II
Preparation of Methyl 4-Oxocaproate (MOC)
from Acetone and Methyl Acrylate (MA)
I with Selected Water-Promoted and
¦ Non-Water Promoted Selected Catalytic Materials
Example Reaction Catalytic Promoting MOC Yield
No. Time (hrs) Material Water (mole %)
(a/mole MA)
I .
I II (a) 5 potassium hydrogen 7.2 90
(b) 5 phthalate none 67
IV (a) 5 montmorillonite 7.2 89
(b) 5 none 55
V (a) 4 alumina 7.2 89
. (b) 5.5 2.0 74
: VI 6 silica-alumina 7.2 74
; VII 6 sulfonated 7.2 74
: perfluorinated
resin
Example VIII
In order to show that the process of the invention is useful for
short reactions such as occur in continuous process operations, an addition
reaction was run with the equipment, starting reactants and in accordance with
the procedures as generally described in Example I, except as hollows: 880 9
. acetone us used and the reaction mixture was heated from room temperature l;o
: 235C in a period of 1.5 hours. As soon as the temperature of the reaction
mixture reached 235C, the reaction mixture was cooled to a temperature of
180C in a period of 5 minutes, and thereafter reached room temperature after
four more hours. After distillation of the reaction mixture, there was
obtained d yiel f 90 percent methyl 4-oxocaproate.
_ 11 _

l~lZ38:Z
Although specific examples of the instant invention have been set
forth hereinabove, it is not intended that the invention be limited solely
thereto, but is to include al l the variations and modifications falling within ¦
the scope of the appended claims.
- 12 -