Process for the selective oxidation of organic compounds

Details Process for the selective oxidation of organic compounds Process for the selective oxidation of organic compounds

1999-03-16

2001-06-26

Shaver, Paul F. (Department: 1621)

Perfume compositions

Perfume compositions

Ring containing active ingredient

C502S158000

Reexamination Certificate

active

06251851

ABSTRACT:

FIELD OF THE INVENTION
The invention generally relates to a process for oxidizing organic compounds. In particular, the invention relates to a process utilizing hydrogen peroxide to oxidize an oxidizable organic substrate in the presence of a silylated titania/silica-containing catalyst and to a preparation of this catalyst.
BACKGROUND OF THE INVENTION
Catalytic oxidation processes are important routes to many commercial chemicals. For example, numerous commercial processes for the epoxidation of olefins have been disclosed in the art. One such process involves the reaction of an organic hydroperoxide with an olefin in the presence of catalytic amounts of certain soluble transition metal compounds (e.g., molybdenum, tungsten, or vanadium napthenates). Some drawbacks to this process include co-production of an alcohol from the hydroperoxide, recovery of the soluble metal catalyst, and the sensitivity of the reaction to water.
Heterogeneous catalysts which overcome some of the aforesaid problems have also been developed. U.S. Pat. No. 3,923,843 claims a process for the epoxidation of an olefinically unsaturated compound comprising reacting the compound in the liquid phase with an organic hydroperoxide in the presence of a catalyst comprising an inorganic siliceous compound in chemical combination with an oxide or hydroxide of titanium. The catalyst is treated with an organic silylating agent before use. In the examples shown, the epoxide selectivity is increased from about 3% to about 15% when comparing the untreated catalyst to the silylated form.
Hydrogen peroxide is often employed as an oxidizing agent for the production of organic chemicals. A wide variety of organic compounds may be oxidized utilizing hydrogen peroxide, for example, olefins can be oxidized to epoxides (oxiranes) using this reagent.
Many titanosilicates have been reported to be useful as oxidation catalysts. For example, the catalytic oxidation of alkanes and alkenes by titanium silicates is disclosed in C. B. Khouw et al., “Studies on the Catalytic Oxidation of Alkanes and Alkenes by Titanium Silicates”, Journal of Catalysis 149, 195-205 (1994). Such catalysts are used for the selective oxidation of n-octane using organic hydroperoxides as the oxidants at temperatures below 100° C. The absence of water is deemed critical for catalytic activity.
In this regard, there is a need for processes that can utilize aqueous hydrogen peroxide rather than organic hydroperoxides to provide both a safe and an efficient process for oxidizing organic compounds. The present invention satisfies that need, but yet can still be used with organic hydroperoxides, and also overcomes certain deficiencies inherent in the prior art. Other objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description which follows hereinafter.
SUMMARY OF THE INVENTION
The invention provides a process for oxidizing organic compounds comprising: contacting, in a zone of reaction, an oxidizable organic compound with a peroxide selected from the group consisting of hydrogen peroxide and organic hydroperoxides, in the presence of a catalytically effective amount of an insoluble catalyst comprising silicon oxide and an oxide of at least one peroxide-activating metal prepared by sol-gel techniques, wherein said catalyst is characterized by (i) the silicon to peroxide-activating atomic ratio is less than 10,000 to 1; (ii) is x-ray amorphous; (iii) possesses a Si—C infrared band; and (iv) has a surface area greater than 500 m
2
/g, a pore volume greater than 0.5 mL/g and an average pore diameter of greater than 4 nm.
Preferably, in the process of the invention, the organic compound is selected from the group consisting of:
(a) cyclic olefins and olefins according to the formula R
1
R
2
C═CR
3
R
4
,
wherein R
1
, R
2
, R
3
and R
4
are each independently —H; alkyl, wherein the alkyl group has from 1 to 16 carbon atoms; alkylaryl, wherein the alkylaryl group has from 7 to 16 carbon atoms; cycloalkyl, wherein the cycloalkyl group has from 6 to 10 carbon atoms; or alkylcycloalkyl, wherein the alkylcycloalkyl group has from 7 to 16 carbon atoms; and wherein said olefin can optionally containing halogen atoms (i.e., Cl, Br, F, and I);
(b) cyclic ketones according to the formula wherein n is an integer from 2 to 9;
(c) compounds of the formula C
6
H
5
R
5
, wherein R
5
is —H, —OH; C
1
to C
3
straight chain, saturated or unsaturated hydrocarbon radicals, —CO
2
H; —CN; —COC
m
, wherein m is an integer from 1 to 6; —OC
m
, wherein m is an integer from 1 to 6; or NR
6
R
7
, where R
6
and R
7
are each independently —H or C
1
to C
3
alkyl groups;
(d) alicyclic hydrocarbons according to the formula R
8
R
9
CH
2
, wherein R
8
and R
9
together from a link of (—CH
2
-)
p
, wherein p is an integer from 4 to 11;
(e) aliphatic hydrocarbons of the formula C
q
H
2q+2
, wherein q is an integer from 1 to 20; and
(f) alcohols according to the formula R
10
R
11
CHOH, wherein R
10
and R
11
are each independently —H; alkyl, wherein the alkyl group has from 1 to 16 carbon atoms; alkylaryl, wherein the alkylaryl group has from 7 to 16 carbon atoms; cycloalkyl, wherein the cycloalkyl group has from 6 to 10 carbon atoms; cycloalkyl wherein R
10
and R
11
taken together form a link containing 4 to 11 —CH
2
- groups; or alkylcycloalkyl, wherein the alkylcycloalkyl group has from 7 to 16 carbon atoms.
The invention also provides a process for the preparation of an aerogel catalyst comprising synthesizing a catalyst comprising oxides of silicon and a peroxide-activating metal by (i) preparing a sol-gel containing silicon and a peroxide-activating metal; (ii) extracting the gel with a solvent to remove substantially all of the water from the gel and optionally removing the solvent; (iii) washing the gel with a solvent for the silylating agent; (iv) treating the gel with a silylation agent; (v) drying the treated gel at a temperature of from about ambient to about 130° C.; and optionally (vi) calcining the gel at a temperature of less than about 400° C.
The present invention further provides a catalyst composition comprising silica and an oxide of at least one peroxide-activating metal characterized by (i) having a silicon to peroxide-activating atomic ratio of less than 10,000 to 1; (ii) being x-ray amorphous; (iii) possessing a Si—C infrared band; and (iv) having a surface area greater than 500 m
2
/g, a pore volume greater than 0.5 mL/g and an average pore diameter of greater than 4 nm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Peroxide-activating metals include, for example, silver, cobalt, cerium, manganese, iron, copper, molybdenum, tungsten, vanadium, titanium, chromium and mixtures thereof. A presently preferred metal is tetrahedrally coordinated titanium. Amorphous titania/silica aerogels prepared according to the process of this invention where the weight ratio of TiO
2
to SiO
2
is between 0.0005:1 and 0.5:1 are the preferred catalyst in the above-named oxidation reactions.
In accordance with this invention, gels containing silica and an oxide of the peroxide-activating metal are prepared by combining a silicate selected from the group consisting of Si(OR
12
)
4
and SiR
14
(OR
13
)
3
, Si(OR
12
)
4
and SiH(OR
13
)
3
, where R
12
is a C
1
to C
4
alkyl group, R
13
is a C
1
to C
8
alkyl group and R
14
is H, C
6
H
5
or R
13
, where C
6
H
5
is a phenyl group, with alkoxides of the peroxide-activating metals, selected from the group consisting of —(OR
13
)
n
where n is the valence of the peroxide-activating metal.
A solution of a concentrated mineral acid such as HCl, HNO
3
or H
2
SO
4
; or an organic acid with a pK
a
equal to or less than 4, such as formic and trifluoroacetic acids; or a base selected from the group consisting of ammonia, and a water-soluble organic amine such as methylamine and ethylamine; optionally water; and an alcohol selected from the group consisting of R
13
OH, where R
13
is as defined above, is prepared. The C
1
to C
4
alcohols are preferred. Th

Affiliated with

Also associated with

Rating

Process for the selective oxidation of organic compounds does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for the selective oxidation of organic compounds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the selective oxidation of organic compounds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2449725