Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
1999-12-22
2002-03-19
Padmanabhan, Sreeni (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S383000, C568S876000, C568S881000, C568S885000, C568S909000
Reexamination Certificate
active
06359179
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a process for the carbonylation of a saturated hydrocarbon to give an oxygenated saturated hydrocarbon. The process involves using a solid strong acid catalyst, such as sulfated zirconia, to catalyze the carbon monoxide addition to the saturated hydrocarbon at reaction conditions to form oxygenates. The oxygenate can be subsequently hydrogenated to provide reduced oxygenates, e.g., ketones can be hydrogenated to alcohols. Alternatively, a hydrogenation component can be added to the solid strong acid catalyst such that reductive carbonylation takes place in one step.
BACKGROUND OF THE INVENTION
Industrial chemicals, to a large extent, contain heteroatoms (O, N, S and halide) prepared by processes in which hydrocarbons are converted to organic compounds containing various heteroatoms. Although saturated hydrocarbons such as paraffins and naphthenes are the lowest cost and most readily available hydrocarbons; they are also very stable and thus not very chemically reactive. Therefore, the most common route to preparing various hetero organic compounds has been to first convert the saturated hydrocarbons to olefins and then react the olefins to produce the hetero organic compounds. While this route to many commercial chemicals has been widely adapted in the industry, it is clear that the direct conversion of saturated hydrocarbons to hetero organic chemicals would be preferable since a major step in the process would be eliminated, thereby resulting in substantial economic benefits.
The fundamental problem in converting saturated hydrocarbons directly to hetero organic compounds is the high stability of the C—C and C—H bonds. In view of the high stability of these bonds, attempts to directly convert saturated hydrocarbons to hetero organic molecules have met with few successes. For example U.S. Pat. No. 2,874,186 discloses a process for reacting carbon monoxide with normal paraffins, isoparaffins and naphthenes to produce ketones, acids and esters. The process involves placing the isoparaffin in a reactor with hydrogen fluoride and boron trifluoride (HF/BF
3
) and carbon monoxide under high pressures. The products, which were obtained from this process, were ketones and carboxylic acids. U.S. Pat. No. 2,346,701 discloses preparing organic oxygen-containing compounds such as ketones and acids by reacting propane with carbon monoxide using an anhydrous aluminum halide catalyst, e.g., aluminum chloride. U.S. Pat. No. 3,356,720 discloses preparing oxygenated organic compounds by reacting saturated hydrocarbons with carbon monoxide using a Freidel-Crafts catalyst and a tertiary alkyl, phenyl alkyl or phenyl carbonyl halide. Both ketones and carboxylic acids are produced. It is also disclosed in WO 98/50336 that branched aliphatic hydrocarbons can be converted to branched aliphatic ketones by reacting the hydrocarbons with carbon monoxide at high pressures and super acidic conditions. The super acidic conditions are produced by the combination of a protic acid such as HF and a Lewis acid such as BF
3
. The reaction is carried out at temperatures of about 0° C. to about 35° C. and pressures of about 10 to 200 atmospheres. Both of these references use a homogeneous liquid system in which the catalyst is a highly corrosive compound. Additionally, means for separating the desired product from the reaction mixture is not disclosed and is anticipated to be very difficult.
At the EuroCat-IV meeting in Rimini, Italy, Sep. 5-10, 1999, M. V. Luzgin and A. G. Stepanov reported that isobutane can be carbonylated with carbon monoxide on sulfated zirconia at 70-150° C. They adsorbed CO and isobutane onto sulfated zirconia and obtained the
13
C NMR spectrum of the catalyst-product complex, which showed the presence of methylisopropyl ketone or pivalic acid. Finally, U.S. Pat. No. 5,679,867 discloses that arylene compounds such as toluene can be carbonylated with carbon monoxide over a solid acid catalyst such as promoted sulfated zirconia to give tolualdehyde.
In contrast to the above references, applicants have developed a process by which saturated hydrocarbons are reacted with carbon monoxide over a solid strong acid catalyst such as sulfated zirconia to give a high yield of an oxygenated saturated hydrocarbon. By oxygenated is meant an oxygen containing saturated hydrocarbon. A specific example is the carbonylation of isobutane to methylisopropyl ketone over sulfated zirconia. Hydrogenation of the oxygenate, e.g., ketone can simultaneously occur by adding a hydrogenation component to the solid catalyst and a reducing agent such as hydrogen. Alternatively, hydrogenation can be carried out in a separate step and reactor.
SUMMARY OF THE INVENTION
This invention relates to the carbonylation of saturated hydrocarbons to provide an oxygenated saturated hydrocarbon. Accordingly, one embodiment of the invention is a process for preparing an oxygenated saturated hydrocarbon comprising contacting a saturated hydrocarbon with carbon monoxide and a solid strong acid catalyst at reaction conditions to provide an oxygenated saturated hydrocarbon product.
Another embodiment of the invention is the reductive carbonylation of saturated hydrocarbons comprising contacting the saturated hydrocarbon with carbon monoxide and a hydrogen source in the presence of a strong acid catalyst containing a hydrogenation catalyst component at reductive carbonylation conditions to provide a reduced oxygenated saturated hydrocarbon product.
These and other objects and embodiments will become clearer after a detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Generally, the present invention relates to the direct carbonylation of saturated hydrocarbons to form the corresponding oxygenated saturated hydrocarbons. As stated, by oxygenate is meant an oxygen containing saturated hydrocarbon, with saturated referring to the hydrocarbon portion of the molecule. Non-limiting examples of these oxygenates are ketones aldehydes and acids. Without wishing to be bound by any particular theory, the reaction pathway by which direct carbonylation to ketones takes place involves the formation of a carbocation species, i.e., a carbenium or carbonium ion which is then reacted, i.e., intercepted, by carbon monoxide molecules forming a relatively stable oxycarbocation. The oxycarbocation undergoes further molecular rearrangement involving an intramolecular hydrogen transfer, i.e., hydride shift, to produce an aldehyde, and an intramolecular methyl shift to convert the aldehyde to the more stable ketone.
Accordingly, those saturated hydrocarbon compounds, which can be used in the present invention, are any of those that can form a carbocation at reaction conditions. The hydrocarbons, which meet these criteria, are any of those which contain at least one of a primary , secondary or tertiary carbon as described in standard organic chemistry texts. Preferred hydrocarbons are those which contain one or more tertiary carbon. For the purpose of this invention, the hydrocarbons which meet these criteria are the saturated hydrocarbons which include alkanes and cyclic alkanes. Although the number of carbon atoms which the saturated hydrocarbons can have is not a critical aspect of this invention, for practical purposes those having 1 to 30 carbon atoms are usually used and thus are preferred.
Included in the general category of alkanes are straight chain alkanes, single and multiple branched alkanes. Cyclic alkanes include cyclic alkanes having one or more alkyl groups attached to the ring. Especially preferred alkanes are the branched alkanes (branched such that they contain one or more tertiary carbon) having from 4 to about 30 carbon atoms. Specific examples of branched alkanes include, but are not limited to, isobutane, isooctane, methylcyclopentane, methylcyclohexane, 2,3-dimethylbutane and 2-methylundecane. Further, mixtures of any of the C
4
-C
30
alkanes can be used in the process and indeed mixtures can lead to very useful products. Examples of these mixtures include, but are no
Bricker Jeffrey C.
Gillespie Ralph D.
Nemeth Laszlo T.
Rabo Jules
Molinaro Frank S.
Padmanabhan Sreeni
Tolomei John G.
UOP LLC
LandOfFree
Direct carbonylation of paraffins using solid strong acid... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Direct carbonylation of paraffins using solid strong acid..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Direct carbonylation of paraffins using solid strong acid... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2873990