Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2002-04-11
2003-12-30
Barts, Samuel (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S322000, C568S347000, C568S357000, C568S385000, C568S398800, C568S399000, C568S403000, C568S430000, C568S431000, C568S469900, C568S470000, C568S485000, C568S814000, C568S884000
Reexamination Certificate
active
06670509
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a process for reacting various organic substrates with oxygen in the presence of a catalyst comprising a bicyclo imide promoter and a metal co-catalyst to provide an oxygenated product. The oxygenated product, e.g. ketone or aldehyde can be further reacted with hydrogen to form the corresponding alcohol and the alcohol can be dehydrated to provide the corresponding olefin.
BACKGROUND OF THE INVENTION
Organic compounds containing an oxygen in the structure have various industrial uses either in and of themselves or as precursors to more valuable products. These oxygenated organic compounds are usually prepared by processes which convert hydrocarbons to the oxygen containing organic compounds. Although saturated hydrocarbons such as paraffins and branched paraffins are the lowest cost and most readily available hydrocarbons, they are also very stable and thus not very chemically reactive. In particular, linear paraffinic compounds are the hardest to oxygenate. It would be very desirable to easily convert paraffins (and especially linear paraffins) to oxygenates.
There are a number of reports in the literature of various ways to oxidize hydrocarbons to the corresponding aldehyde or ketone. One reference is U.S. Pat. No. 5,958,821 which discloses oxidizing various hydrocarbons such as cycloalkanes, aromatic hydrocarbons, etc. with oxygen in the presence of an oxidation catalyst comprising an imide compound such N-hydroxyphthalimide and a metal compound co-catalyst such as cobalt or manganese acetyl acetonate. The patentee of the '821 reference enumerates virtually every class of known hydrocarbons and virtually every metal in the periodic table. Other references which have addressed the oxygenation of alkanes include Shun-Ichi Murahashi et al. in
J. Chem. Soc, Chem. Commun
.,(1993) 139-140 in which the authors present results for the oxidation of alkanes and alkenes with oxygen in the presence of aldehydes and using a copper compound catalyst. Their results showed that linear alkanes such as n-decane had extremely low conversion. In
Catalysis Letters
8 (1991), 45-52 the same authors have shown that isobutane can react with oxygen in the presence of an iron perhaloporphyrin complex to give mostly tert-butyl alcohol. Shun-Ichi Murahashi et al. have reported in
Tetrahedron Letters
, (1993), vol. 34, no. 8 pp. 1299-1302, 1993 the ruthenium catalyzed oxidation of alkanes with alkyl hydroperoxide. Specifically, they reacted n-heptane and n-decane to provide ketones and alcohols. G. P. Khimova et al. in
Petrol. Chem U.S.R.R
. (1981), vol. 21, no. 1, pp. 49-52 have reported the liquid phase oxidation of isobutane using a heterogeneous catalyst containing cobalt and molybdenum borides or molybdenum carbides. The main products of this reaction were tert-butyl hydroperoxides, tert-butyl alcohol and acetone. It has also been shown in U.S. Pat. No. 5,395,980 that isobutane can be converted to tert-butyl hydroperoxide at elevated temperatures (about 140° C.) by reacting it with oxygen in the presence of tert-butyl alcohol and di (tert-butyl) peroxide.
There are also reports of the oxidation of alkanes with oxygen using N-hydroxyphthalimide (NHPI) as a catalyst and a metal compound co-catalyst. For example, Y. Ishii et al. in
Catalysis Surveys from Japan
3 (1999) 27-35 report the oxidation of various alkanes including isobutane. The isobutane gave tert-butyl alcohol and acetone and tert-butyl hydroperoxide. The other alkanes which were tested were all branched alkanes. Ishii et al. in
J. Org. Chem
.(1996), 61, 4520-4526 present results of the oxidation of various cycloalkanes using NHPI and Co(acac)
n
. Results are also presented for the oxidation of n-octane to give octanols and octanones. Further, U.S. Pat. No. 6,037,507 discloses the oxidation of branched aliphatic hydrocarbons using an imide promoter. It has also been reported that aromatic compounds such as p-xylene can be oxidized to carboxylic acids by using a mixed metal catalyst. See e.g.
J. Phys. Chem A
2001, 105 5881-5884.
Applicants have found that the use of a bicyclo imide compound having two NHPI units gives improved results versus using twice the equivalent of NHPI itself. Applicants have further found that the use of solvents such as sulfolane provides improved activity versus acetic acid.
SUMMARY OF THE INVENTION
As stated, the present invention relates to a process for converting organic substrates to oxygenated compounds and then optionally converting the oxygenated compounds to olefins. Accordingly, one embodiment of the invention is a process for converting an organic substrate to an oxygenated compound comprising reacting the organic substrate with an oxygen source in the presence of a catalyst comprising an imide promoter and a co-catalyst at oxidation conditions to provide an oxygenated compound, the imide promoter being represented by at least one of structures (I), (II), (III), or (IV):
where R
1
, R
2
, R
3
and R
4
are independently selected from the group consisting of hydrogen, halogens, alkyl groups, cycloalkyl groups, aryl groups, sulfonyl groups, sulfonic acid, hydroxyl groups, alkoxy groups, carboxyl groups, ethers, amines, amides, alkoxy-carbonyl groups and acyl groups; and X is selected from the group consisting of O, OH, acetyl, acetoxy, ether and halogen and the co-catalyst comprising at least one metal selected from the group consisting of Groups IB, IVB, VB, VIB, VIIB and VIII metals of the Periodic Table of the Elements.
Another embodiment of the invention is to take the oxygenated compound of the previous paragraph and react it with hydrogen in the presence of a hydrogenation catalyst at hydrogenation conditions to provide alcohols and then optionally contacting the alcohols with a dehydrogenation catalyst to provide olefins.
These and other objects and embodiments will become clearer after a detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
One essential part of the present invention is a catalyst which comprises an imide promoter and a co-catalyst. The imide promoter has at least one of the structures below.
where R
1
, R
2
, R
3
and R
4
are independently selected from the group consisting of hydrogen, halogens, alkyl groups, cycloalkyl groups, aryl groups, sulfonyl group, sulfonic acid, hydroxyl groups, alkoxy groups, carboxyl groups, ethers, amines, amides, alkoxy-carbonyl groups and acyl groups; and the co-catalyst comprising at least one metal selected from the groups consisting of Groups IB, IVB, VB, VIB, VIIB and VIII metals of the Periodic Table of the Elements. X is selected from the group consisting of O, OH, acetyl, acetoxy, ether and halogen.
In any of the imide structures I to IV, when R
1
, R
2
, R
3
and/or R
4
represent halogens, these include iodine, bromine, chlorine and fluorine. Alkyl groups include without limitations, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, heptyl, other straight chains or branched chain alkyl groups having alkyl branches of 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms and most preferably 1 to 4 carbon atoms.
Specific examples of aryl or aromatic groups, without limitation, are phenyl groups and naphthyl groups. Cycloalkyl groups include without limitation cyclopentyl, cyclohexyl, cyclooctyl, etc. Specific examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, isobutoxy, isopropoxy and other alkoxy groups having from 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms and most preferably 1 to 4 carbon atoms. Alkoxy-carbonyl groups include those having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms and most preferably 1 to 4 carbon atoms. Specific examples include, without limitation, methoxy carbonyl, ethoxy carbonyl, isopropoxy carbonyl, pentyl oxycarbonxyl, etc. Acyl groups are any of those containing 1 to 6 carbon atoms and include formyl, acetyl, propionyl, isobutyryl, etc.
These imide compounds can be prepared by conventional methods in which an acid anhydride reacts with a hydroxylamine to give an imide. Some of thes
House David W.
Kurek Paul R.
Barts Samuel
Molinaro Frank S.
Tolomei John G.
UOP LLC
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