CA1120457A

CA1120457A - Preparaion of ketones

Info

Publication number: CA1120457A
Application number: CA000283638A
Authority: CA
Inventors: Russell M. Bimber; Richard L. Cryberg
Original assignee: Diamond Shamrock Corp
Current assignee: Diamond Shamrock Corp
Priority date: 1976-08-20
Filing date: 1977-07-28
Publication date: 1982-03-23
Also published as: GB1591540A; FR2375179A1; FR2375181B1; FR2375182A1; JPS5325511A; FR2375179B1; GB1591539A; JPS6256141B2; FR2375180A1; BE857956A; FR2375180B1; DE2737511C2; GB1591538A; FR2375181A1; FR2375182B1; DE2737511A1

Abstract

ABSTRACT OF THE DISCLOSURE
Disclosed is a method for the preparation of ketones by a catalytic vapor phase reaction of ketones with carboxylic acids. An example of such a reaction is that of acetone with pivalic acid over a ceria-alumina catalyst at a temperature of nearly 470°C. to producepinacolone..

Description

PREP~RATION OF KETONES
.

~A~KGROUND OF THE INVENTION

The present invention relates generally to a method for preparing ketones from ketones and carboxylic acids. More particularly, it relates to an entirely new process for the production of unsymmetrical ketones from ketones and carboxylic acids over a ceria-alumina catalyst system in the temperature range of 300 to 550C. utilizing a very short contact time over the catalyst to achieve a conversion in the range of ~5 percent or more while recovering most of the unconverted reactants for recycling. An excellent example of such a reaction is the reaction of acetone with pivalic acid over a ceria-alumina catalyst to produce pinacolone.
Pinaco].one is an intermediate which is useful in the preparation of pharmaceutical products and pesticides for which improved methods of manufacture have been sought for some time now. An electrolytic reductive coupling of acetone to form pinacol which can be converted to pinacolone has been carried out on experimental basis for a number of years to produce small quantities of pinacol but such processes have thus ~ar failed to receive much commercial utilization because of the cost factors involved in these methods.
A thermo-chemical route as taught by literature utilizes a pyrolysis of one or two carboxylic acids to yield symmetrical or unsymmetrical ketones, respectively. This type of reaction has been used commerci.ally with the significant disadvantage that the raw materials used in the manufacture of the ketones are ccstly because the selectivity of the reaction ; to unsymmetrical ketones is low.

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ThereEore, as ~ith all chemlcal processes, it would be very desirable to be able to reduce the cost of a thermo~
chemical route to the pinacolone or other ketones for use in the chemical industry on a commercial basis.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a method for the preparation of ketones from ketones and carboxylic acids so as to produce a high yield of the ketone while lowering the overall cost of capital lnvestment and raw materials used in such a process.
It is a further object of the present invention to provide a catalyst system for promoting such novel chem:Lca].
reactions within the range of commercial utiliza~ion.
These and other ob~ects of the present invention, and the advantages thereof over the prior art forms, will become apparent to those skilled in the art Erom the detailed disclosure of the present invention as set forth heleinbelow.
A method has been found for the production of ketones comprlsing the steps of: introducing a ketone and a carboxylic acid into a chamber; passing the mixture of the ketone and the carb~oxylic acid over a heated catalytically active material;
and recovering the ketone.
It has also been found that unsymmetrical ketones can be produced by: mixing a ketone and a carboxylic acld; passing the mixture through a catalyst bed consisting essentially of a ceria-compound on an alumina support; and recovering the unsymmetrical ketone.

It has also been found that an unsymmetrical ketone may be produced by: mixing two different symmetrical ketones;

)457 passing the mixture through a catalyst bed consisting essentially of a ceria-compo~lnd on an alumina support; alld recovering the unsymmetrical ketone.

D~SCRIPTI ~

Unsymmetrical ketones may be produced according to ~he general reaction R2C0 ~ 2R'C02H to yield 2RR'C0 ~ C02 ~ H20 wherein R is a hydrocarbon radical and R' is a hydrocarbon radical other than R. This reaction has been found to occur over catalytically active materials with a relatively shor~
contac~ time in a temperature range of 300 to 550C. Unsymme-trical ketones resulting from the above-cited reaction can be recovered in yields up to 80~ or more. Groups representative of R and R' in the above-clted starting materials would i.nclude aliphatic groups such as methyl, ethyl, propyl7isopropyl,t-butyl, :~ pentyl, he~yl, and benzyl as well as aromatic substituents such as phenyl, p-tolyl and naphthyl.
It is believed that the above-cited reaction will take place by passing the vapors of the reactants over heated catalytically active materials such as iron filings, alumina, manganous oxides, thoria, or ceria types of catalysts. The preferred catalyst system from experience, however, lS a ceria compound deposited on an alumina, silica or carbon support.
In each specific case conditions may need to be altered slightly to maximize yields. For example, acetone and pivalic acid react over a ceria-alumina catalyst at a temperature near 470C. to produce pinacolone. When using a two:one molar ratio of acetone:pivalic acid with a ten second contact time, the conversion of the pivalic acid to pinacolone was in the range of 80~ of theoretical. Additionally most of the unconverted reactants can be recovered and refed into the reactor zone to accomplish higher yields. By recycling reactants virtually 100%
conversion rates are possible. This resul~s in about t~o moles of pinacolone being produced per e~ery one mole of acetone consumed.
The catalyst can be a cerium acetate converted to ceria on an alumina support such tha~ a good activity will be produced if the ceria concentration is in the range of 1 to 10%
ca~culated as CeO2 to total weight. The amount used will depend upon the specific surface area presented by the alumina support.
Where the support is alumina available from Harshaw Chemical Company under the trademark of Harshaw Al 1404 T-1~8~ ~is equals~
approximately 190 square meters per gram, and the range oE ceria is preferably 5 to lOZ. ~o treatment prior to use is necessary but a slight aging of the catalyst has been found during initial use, as is usual with such catalyst systems. Thereafter thi~
system will provide good activity of a steady na~ure for time pèriods in excess of 1,000 hours of use. The ceria-alumina catalyst provides a distinct advantage over thoria catalysts because the ceria is not radioaceive thus eliminating a hazard of thoria and the inconvenience o~ Nuclear Regulatory Commission licensing and regulation~ covering its use.
~ t is bel~eved that the above-described acetone and pivalic acid reaction to obtain pinacolone may proceed as follows.

2(CH3)3C-COOH + CH3COCH3 ceri -alumina~

2CH3-COC(CH3) 3 ~ C2 ~ H~O
It will be noticed ~hat two moles of the pivalic acid combine with one mole of the acetone ~o provide two moles of pinacolone. It is believed that the pivalic acid forms a complex with the ceria-alumina catalyst system by losing the acidic hydrogen atom off of the pivalic acid. Thereafter the carbon to oxygen double bond .
v~3 ~' 45'7 is attacked by the methylene anion of the acetone to provide a shift of electrons to the oxygen atom and the loss of an oxygen atom with the coupling of the acetone by its methyl group there~o.
This results in a probable intermediate of the formula (CH3)3 CCOCH~COCH3. It is believed then that this intermediate is hydroly~ed causing a cleavage which results in pinacolone and an acetic acid group leaving which will thereafter react with a second complexed pivalic acid group to form more pinacolone. In this process, carbon dioxide and water are also formed.
Further examples of ketones produced from ketones and carboxylic acids include: acetone and benzoic acld to obtain aceto-phenone; acetone and propionic ~cid to obtain methyl e~hyl ketone and diethyl keto~e; acetone and dimethyl succinate to obtain 2,5-hexandione; acetone and phenylacetic acid to obtain phenyl~
acetone; diethyl ketone and acetic acid to obtain acetone and methyl ethyl ketone; diethyl ketone and benzoic acid to obtain propiophenone; benzophenone and acetic acid to obtain acetophenone~
benzoic acid and methyl ethyl ketone to obtain acetophenone and propiophenone; and acetone and dimethyl terephthalate to obtain p-diacetylbenzene.
In some cases alcohols or aldehydes may be substituted for the carboxylic acid to produce the ketones of this process.
It has been found that benzyl alcohol or benzaldehyde may be substituted for benzoic acid in the reaction wich acetone to obtain acetophenone. It i9 believed that reactions using the aldehyde or alcohol for a starting material proceed by an oxida-tion-reduction disproportionation of the feedst~cks. It is also possible that the ketonic products are for~ed through carboxylic acid intermediates.

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It has also been found that the ceria-alumina catalyst provides good activity for rearrangements of ketones by themselves such as methyl ethyl ketone alone to ob~ain acetone and diethyl ketone and acetone and diethyl ketone to obtain methyl ethyl ketone.
It is believed that the ceria-alumina ca~alyst will, provide good activity for numerous other chemical reactions besides the ke~one reactions described above. This catalyst would be useful in reactions like: benzophenone and pivalic acid to obtain t-butyl phenyl ketone; 1,3-dichloroacetane and pivalic acid to obtain monochloropinacolone; and cyclopentanone and acetIc acid to obtain 2,7-octanedlone.
It is also believed that the ceria-alumina catalyst will provide good activity for many other reactions falllng within the fol1Owing general types.
RC~2X ~ CH3COCH3 to yield RCH~CH2COCH3 + HX, where R is an activating group such as h~drogen, alkyl or aryl and X is a good leaving group such as a halogen.
RCH3 + R~CO~H to yield RC~COR1, where R i~ an election withdrawing group such as 2 or 4 pyridyl and R1 is alkyl or aryl~
RC~2COCH2R f HCCOH to yield RCH2CHO
~ where R ls hydrogen, alkyl or aryl.
;` This process will provide a distinct economic advantage over prior methods, particuLarly for production of pinacolone over either the mixed acid pyrolysis route or the formation of the ~ixed anhydrides and subsequent pyrolysis to the ketones.
Lower capital and operating costs are expected in the process of the presen~ invention versus that of the mixed acid pyrolysis because the heat of vaporization of acetone is less than that of acetic acid, thus requiring less energy. This is increased by :
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the fact that one mole of acetone is nearly equal to two moles of acetic acid used in the old methods. Further, about one-half as much carbon dioxide and water are produced making it easier to condense and recover the product and unreacted materials.
There is also less dilution of the reaction mixture with byproduct carbon dioxide and water so that a reaction vessel only two-thirds to three-quarters as large as that used in the acid pyrolysis route may be used to result in a savings in the cost of catalyst and reactor. In addition, smaller condensers with lower energy requirements will be adequate.
In order that those skilled in the art may more readily understand the present invention and certain preferred aspects by which it may be practiced, the following specific examples are afforded to show the method of preparation of the various ketones according to the general reaction cited above.

EXA~LE 1 An apparatus suitable for use in the above-described reactions was assembled having a vertical tube furnace construct-ed over Pyrex~tubing for heating the reaction zone. The reaction tube contained a thermowell in the reaction zone to obtain accurate ~temperature readings. The upper section where the reactants enter contained a preheater segment to bring the reactants up to reaction temperature while the lower section conta~ned a smaller heating segment to sustain these temperatures.
The preheater was thermostatically controlled to provide more heat when reactants were being fed into the section to maintain the temperature. The catalyst should be positioned between glass beads so that it begins just below upper section and runs down approximately 75~ of the length of the lower section and between the concentric thermowell and the glass that contains the reactor.

The reac~or was connected by means of a "Y" tube to a condensate receiver on the bottom and two water cooled condensers in series on the vertically straight neck~ For example, the lower conden-ser may be of a six bulb Allihn type and the upper one of ~he Friedrich's type. Also it might be desirable to use a feed reservoir on a triple beam balance connec~ed to a metering pump to feed the reactants to ~he system at a k~own rate. With a "Y~ tube connected to the upper section or the tube furnace, the reactants may be fed into one branch and a thermocouple well placed in the other branch for measuring temperatures.
A thoria catalyst was prepared from 40 grams of thoria nitrate tetrahydrate ~Th~N03)4 4~20] in water, impreg~ated on 200 ml. or 172 grams of Harshaw Alumina catalyst AL1404 T 1/8~.
The wetted alumina was stripped of water in a rotary evaporator under aspirator vacuum. This was transferred to a large porcelain dish where it was heated qtrongly while aspirating the NOX from it through a water trap. The resulting loose material was then placed into the reactor tube with glass beads ahead and behind the catalyst zone.
The ~ystem was then flushed out with acetone vapors to clear the system of any residues and the catalyst temperature gradually rose to 440 to 485~C. The feed reservoir was changed from acetone to a 2:1 molar ratio of acetone:pivalic acid. The condensate samples removed were composed of 4 to 5 parts red organic layer over a colorless aqueous layer. Product purifica-tion and gas chromatographic studies of the organic layer showed the presence of pinacolone in yields ranging as high as 90% of theoretical on a single pass. Recovery of reactants and recycling can achleve even higher yields.

)457 A ceria catalyst was prepared from 100 grams of cerium acetate hydrate [Ce~OAc)3 XH20] and 400 ml. of water at room temperature with agitation to dissolve nearly all of the material. The solution was filtered and xlnsed with several portions of water to result in approximately 460 ml. of filtrate.
The solution was then combined with 1050 grams of Harshaw Alumina catalyst Al 1404 1/8~and tumbled in a gallon jug. The solution was absorbed to leave no freely pourable liquid and thus wetting the alumina. The mixture was dried in a porcelain dish at approximately 200C. for 15 hours and then installed in the apparatus according to Example 1.
The system was flushed out according to Example 1 and the feed reservoir charged with a 2:1 molar ratio of acetone:
pivalic acid. Pinacolone product was recovered from ~he conden-sate in yields up to 90~ of theoretical as evidenced by gas chromatographic studies.

EXAMPLES 3~12 Using the apparatus of Example 1 and the catalyst of Example 2 other reactions can be performed in a fashion similar to Examples 1 and 2. In each case the reaction products were confirmed by mass spectra and quantltatively measured by gas chromatographic studies. These reactions are summarized in the following Table 1. The Molar ~atio refers to the ratio of the reactants in the order stated in the feed reservoir. With the exception of the pinacolone, no effort was made to maximize the yields.

a) al o o o ,, ~ V
u~ ~ a) ' a V ~ ~
o o rl O ~ O ~ ~ O V
o o ~ ~ o o ~ C) d ~ ~
O ~ ~1 0 O 0 ~ 5r! p~ O~ 0 0 '1~~ 0 V 5~
a ~ v ~ ~ o ~1 c~ U
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u~ oo ~ O O u~ oo r~~ I~ ~D
~ c~
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cr;
~( ~

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~
1~O t~ O U~ O O O O
~rl O ~ CO O
~ ~ ~ `J ~ Lr~
~1~ P. l l l l l l ~q~ ~3 O O O O O O O O: O O
c~ . o a) ~ n o ~;t E~ ~

~ V
~ ~ v r~ h .. r15~ h d a . .. .c d O O a a~ ~ r~
r1 ~dr1 a) ~ v ~V r1 c ~ r1 h ~ ~D
c~ ~ r~ r~ a~ r~ O r1 c~ r~

u~ ~ d C) ~ v v J.~ r~
a ~ r-~r-l ~.) . r! tJ O
tl~ r1 a a o a a ~ ch ~ h-r~ J r17~1 ~ d IJ O O O rlO r1 0 r1 ::: rl r- o rl O h ~ ~ O
C) N ~ J .~ ~ V VJJ N N ~ N r' 5: 0 Ll ~ a ~ ~ oa) o ~ a a c~ ~ v J~
a) ~ r1 c~ r1 ~: D ~ d ~ td~ D ~ ~d D El E i ~

r-l r-l r-l ~n ..
t~ a~
~ N
O
a ~:
O O
~ a a o a~
C~
o ~ o O
'~
~ ru ~ a~
,1 I t~

O

~_ ~ C~
~d ~ ~ ..
.. .. ~, O O C~ .-~: ~a ~ ~ ~
~ ~ ~ : : ~' a o c u~
CO
;q V
~ ~ ~ l l l E~ ~ ~ O O O
; p~a) ~ oo CO

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:~ .~
a~
a) ~
~ JJ
U~ ~ ~ .C .0 3 JJ .. ,~ ~ a) -a ~ v ~ ~,, a.c ~ a o O ~d 0~1 tJ V aJ ,J N JJ O
Cd Q~ h Q) ,t~
a .0 O
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X ~ ~ U~
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~f~5~7 Thus, it sho~llcl be readily apparent from the foregoing description of the preEerred embocliments that the method herein-above described accomplishes tihe objects of the invention and solves the problems attendant to the method of preparation of ke~ones.

.

Claims

WHAT IS CLAIMED IS:

1. A method for the production of ketone from one or more other ketones comprising:
I. reacting one or more starting compounds comprising;
a) an unsymmetrical ketone; or b) a symmetrical ketone in admixture with at least one other compound selected from the group consisting of; carboxylic acids, carboxylic acid esters, aldehydes, alcohols and additional different ketones; or c) two symmetrical ketones, optionally in admixture with at least one other compound from the group consisting of; carboxylic acids, carboxylic acid esters, aldehydes, alcohols and additional differ-ent ketones;
II. passing said starting compound or compounds into con-tact with a catalytically-active material at a reaction temperature in the range of from about 300°C to 550°C;
and III. recovering the desired ketone from the resultant reaction products.

2. A method according to Claim 1 wherein the catalytically-active material is a ceria compound on a support.

3. A method according to Claim 1 wherein the catalytically-active material is a ceria compound on an alumina support.

4. A method according to Claim 1 wherein the reaction contact time of the reactants and the catalytically-active material is in the range of from greater than 0 to 60 seconds.

5. A method according to Claim 1 wherein said ketone is acetone and said other compound is pivalic acid yielding pinacolone.

6. A method according to Claim 1 wherein said ketone is ace-tone and said other compound is benzoic acid yielding acetophenono.

7. A method according to Claim 1 wherein said ketone is ace-tone and said other compound is propionic acid yielding a mixture of methyl ethyl ketone and diethyl ketone.

8. A method according to Claim 1 wherein said ketone is ace-tone and said other compound is dimethyl succinate, derived from succinic acid, yielding 2,5-hexanedione.

9. A method according to Claim 1 wherein said ketone is ace-tone and said other compound is phenylacetic acid yielding phenylacetone.

10. A method according to Claim 1 wherein said ketone is diethyl ketone and said other compound is acetic acid yielding methyl ethyl ketone.

11. A method according to Claim 1 wherein said ketone is diethyl ketone and said other compound is benzoic acid yielding propio-phenone.

12. A method according to Claim 1 wherein said ketone is benzophenone and said other compound is acetic acid yielding aceto-phenone.

13. A method according to Claim 3 wherein said alumina support is Harshaw Al 1404 T-1/8? having a specific surface area of 190 sq. m/g.

14. A method according to Claim 2 wherein the concentration of said ceria compound is in the range of 1 to 10%.

15. A method according to Claim 2 wherein the concentration of said ceria compound is in the preferred range of 5 to 10%.

16. A method according to Claims 2 or 3 wherein said ceria compound is derived from cerium acetate.

17. A method for producing unsymmetrical ketones from symmetrical ketones comprising: forming a mixture of a symmetrical ketone of the formula R2CO and a carboxylic acid of the formula R'CO2H or derivative thereof including carboxylic acid ester, carboxylic acid anhydride, alcohol and aldehyde derivatives, wherein R is a hydrocarbon radical and R' is a hydrocarbon radical different from that of R; passing said mix-ture of symmetrical ketone and carboxylic acid or derivative into contact with a heated catalytically-active material at a temper-ature within the range of from 300 to 550°C; and recovering the unsymmetrical ketone.

18. A method for producing symmetrical ketones comprising:
passing an unsymmetrical ketone into contact with a catalyst bed con-sisting essentially of a ceria compound on an alumina support at a reaction temperature in the range of from about 300 to 550°C; and recovering the symmetrical ketones.

19. A method for producing an unsymmetrical ketone comprising: mixing two-different symmetrical ketones; passing the mixture into contact with a catalyst bed consisting essentially of a ceria compound on an alumina support at a reaction temperature of from about 300 to 550°C; and recovering the unsym-metrical ketone.

20. A method according to Claim 19 wherein the symmetrical ketones are acetone and diethyl ketone and the un-symmetrical ketone is methyl ethyl ketone.

21. A method for producing a ketone of the formula RCH2CH2COCH3 where R equals an activating group, comprising:
mixing acetone and a compound of the formula RCH2X where R is an activating group selected from the group consisting of hydrogen alkyl and aryl and X is a good group; passing said mixture into contact with a catalyst bed consisting essentially of a ceria compound on an alumina support at a reaction temperature in the range of from about 300 to 550°C; and recovering the product.

22. A method for producing a ketone of the formula RCH2COR' comprising; mixing a compound of the formula RCH3 and a compound o the formula R'CO2H where R is an electron withdrawing group, R' is selected from the group consisting of alkyl and aryl; passing said mixture into contact with a catalyst bed consisting essentially of a ceria compound on an alumina support at a reaction temperature in the range of from about 300 to 550°C; and recovering said product.