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United States Patent 4,766,249
Buck , et al. * August 23, 1988
Method of catalytically hydrolyzing alpha, beta-unsaturated carbonyl compounds
Abstract
Alpha, beta-unsaturated carbonyl compounds are hydrolyzed under alkaline conditions in the presence of water to produce additional carbonyl-containing compounds. High yields are obtained when the alkaline catalyst contains hydroxide ion and the pH is maintained in the range of about 11 to about 13.
Inventors: Buck; Keith T. (Cincinnati, OH); Boeing; Anthony J. (Cincinnati, OH); Dolfini; Joseph E. (Cincinnati, OH); Glinka; Jerome (Cincinnati, OH)
Assignee: Mallinckrodt, Inc. (St. Louis, MO)
- Notice: The portion of the term of this patent subsequent to June 16, 2004 has been disclaimed.
Appl. No.: 942491
Filed: December 24, 1986
Current U.S. Class: 568/433; 568/458
Intern'l Class: C07C 045/42
Field of Search: 568/426,433,435,437,440,458
References Cited [Referenced By]
Other References
Guthrie et al., "Can. J. Chem.", vol. 62, pp. 1441-1445, (1984).
Primary Examiner: Lone; Werren B.
Attorney, Agent or Firm: Wood, Herron & Evans
Parent Case Text
RELATED APPLICATION
This is a continuation-in-part of application Ser. No. 856,595, filed Apr. 25, 1986, invented by Keith T. Buck, Anthony J. Boeing and Joseph E. Dolfini, and assigned to the assignee of this application, now U.S. Pat. No. 4,673,766.
Claims
What is claimed is:
1. A method of producing a carbonyl-containing compound which comprises
hydrolyzing by dispersing in water an alpha, beta-unsaturated carbonyl compound of the formula ##STR3## to produce a carbonyl-containing compound and by-product according to the following formulas ##STR4## wherein R' and R" are hydrogen, aliphatic or aromatic hydrocarbon groups or substituted derivatives thereof, and R"' is an aliphatic or aromatic aldehyde- or ketone-containing group having the carbon to oxygen double bond of said aldehyde or ketone conjugated with the alpha, beta double bond between C and R"' of alpha, beta-unsaturated alpha,beta-unsaturated carbonyl compound, and
conducting said hydrolysis of the alpha, beta-unsaturated carbonyl compound under the action of heat in the presence of a catalytic amount of hydroxide ion and at a pH of about 11 to about 13.
2. The method of claim 1 which is conducted at a pH in the range of about 12 to about 12.5.
3. The method of claim 1 wherein the individual carbonyl-containing compounds obtained from said hydrolysis reaction are fractionally distilled for separation in substantially pure form.
4. The method of claim 1 conducted in the presence of an anionic or non-ionic surfactant.
5. The method of claim 1 conducted under shearing agitation to facilitate the dispersion of the alpha, beta-unsaturated carbonyl compound in the water.
6. The method of claim 1 wherein said alpha, beta-unsaturated carbonyl compound is citral and the carbonyl-containing compounds produced are 6-methyl-5-hepten-2-one and acetaldehyde.
7. The method of claim 1 wherein said alpha, beta-unsaturated carbonyl compound is pulegone and the carbonyl-containing compounds produced are acetone and 3-methylcyclohexanone.
8. A method of producing a carbonyl-containing compound which comprises
hydrolyzing by dispersing in water under shearing agitation in the presence of an anionic surfactant an alpha, beta-unsaturated carbonyl compound of the formula ##STR5## to produce a carbonyl-containing compound and by-product according to the following formulas ##STR6## wherein R' and R" are hydrogen, aliphatic or aromatic hydrocarbon groups or substituted derivatives thereof, and R"' is an aliphatic or aromatic aldehyde- or ketone-containing group having the carbon to oxygen double bond of said aldehyde or ketone conjugated with the alpha, beta double bond between C and R"' of said alpha, beta-unsaturated carbonyl compound, and
conducting said hydrolysis of the alpha, beta-unsaturated carbonyl compound under the action of heat in the presence of a catalytic amount of hydroxide ion and at a pH of about 12 to about 12.5.
Description
BACKGROUND OF THE INVENTION
The retroaldol reaction of cinnamaldehyde is well known. In this reaction, cinnamaldehyde is converted to benzaldehyde and acetaldehyde with various potential side reactions. Recently, for example, an investigation of the kinetics of the retroaldol reaction of cinnamaldehyde has been reported by J. Peter Guthrie, et al, Can. J. Chem., Vol. 62, pp. 1441-1445 (1984). The conversion of the cinnamaldehyde to benzaldehyde has been long known and well studied. However, it has not been heretofore known to produce benzaldehyde from cinnamaldehyde in substantial yields, and favorable reaction conditions for production of such yields have not been reported. Similarly, citral has been hydrolyzed via the retroaldol reaction to produce 6-methyl-5-hepten-2-one and acetaldehyde. Again, however, product yield is low. Up to now, it has not been known how to obtain carbonyl-containing reaction products in substantial yields through the retroaldol hydrolysis of any of the alpha,beta-unsaturated carbonyl compounds, of which cinnamaldehyde and citral are examples.
SUMMARY OF THE INVENTION
The invention disclosed in the above application Ser. No. 856,595 is directed to a method of making benzaldehyde by conversion of cinnamaldehyde in the presence of water with surprisingly high yields heretofore unachieved. The invention involved the dispersion of cinnamaldehyde in water and, in the presence of an effective catalytic amount of hydroxide ion, fractionally steam distilling benzaldehyde from the cinnamaldehyde. The reaction was conducted at a pH on the order of about 11 to about B 13 and, unexpectedly, within this pH range it has been discovered that a substantial conversion of cinnamaldehyde to benzaldehyde could be achieved on the order of about 75% or more. It has also been found that the conversion may be achieved at such a high pH without adverse side reaction.
It has also been found that members of the class of compounds known as alpha,beta-unsaturated carbonyl compounds, of which cinnamaldehyde is an example, can be hydrolyzed via the retroaldol reaction to produce carbonyl-containing compounds in substantial yields.
In a preferred mode of conducting the method, the alpha,beta-unsaturated carbonyl compound is dispersed in water in the presence of shearing agitation. It will be understood that other water soluble or dispersible cosolvents such as alcohols, ethers or the like may be used in the aqueous reaction medium. An anionic surfactant such as sodium lauryl sulfate or a non-ionic surfactant such as polyethylene glycol having a molecular weight in the range of 400 to 600 may be used. Preferably, the hydroxide ion is furnished by means of sodium hydroxide which also achieves a pH in the range of about 11 to about 13. After the starting materials have been charged to the flask, reaction is initiated with the addition of heat. Once reaction has begun, separation of the products is achieved through the production of water-product azeotropes which are isolated by fractional distillation. It has been critically determined that the fractional distillation must be conducted at a pH within the range of about 11 to about 13, preferably about 12 to about 12.5. Reactions conducted outside this pH range exhibit very poor conversion to desired product because side reactions, polymerization and other adverse reactions occur.
Reactions conducted within the pH range of about 11 to about 13, and especially between about 12 and about 12.5, produce significant yields on the order of 75% or greater and are substantially free of side reaction products. These results are considered to be unexpected especially at the high pH levels of the reaction where it may have been expected that side reactions would have significantly lessened or prevented the yield for the desired product.
The reaction products isolated by fractional distillation may be further purified by means of additional separation techniques. The separation technique employed may vary with the degree of purity sought. Pure alpha,beta-unsaturated carbonyl compounds may be used as starting materials for the reaction. However, product yield percentage is not adversely affected when natural products containing the desired starting materials are used in the reaction. Thus, a natural product such as cassia oil containing substantial amounts of cinnamaldehyde may be used successfully in this invention. Similarly, lemon grass oil containing citral may be used successfully. Also, pennyroyal oil may be utilized under the teachings of this invention as a source of pulegone, an alpha,beta-unsaturated carbonyl compound.
DETAILED DESCRIPTION
The method in its broader aspects is practiced by hydrolyzing after dispersing in water an alpha,beta-unsaturated carbonyl compound having the formula ##STR1## to produce a carbonyl-containing compound and a by-product having the general formulas ##STR2## The substituents R' and R" are hydrogen, aliphatic or aromatic hydrocarbon groups or substituted derivatives thereof, and R"' is an aliphatic or aromatic aldehyde- or ketone-containing group having the carbon to oxygen double bond of the aldehyde or ketone conjugated with the alpha,beta double bond between C and R"' of the alpha,beta-unsaturated carbonyl compound. The hydrolysis reaction proceeds under the action of heat and is catalyzed by hydroxide ion having a concentration level sufficient to maintain the solution pH between about 11 and about 13.
A large number of alpha,beta-unsaturated carbonyl compounds may be hydrolyzed according to the teachings of this invention. The compounds in the following non-comprehensive list are included under the description of hydrolyzable alpha,beta-unsaturated carbonyl compounds: cinnamaldehyde to produce benzaldehyde and acetaldehyde; citral to produce 6-methyl-5-hepten-2-one and acetaldehyde; pulegone to produce 3-methylcyclohexanone and acetone; 3-decen-2-one to produce heptanal and acetone; 2-dodecenal to produce decanal and acetaldehyde; 2-heptenal to produce pentanal and acetaldehyde; 2-hexenal to produce butanal and acetaldehyde; ionone to produce cyclocitral and acetone; irone to produce 2,5,6,6-tetramethyl-cyclohex-1-ene-1-carboxaldehyde and acetone; 1-(4-methoxyphenyl)-1-penten-3-one to produce paramethoxybenzaldehyde and methyl ethyl ketone; 5-methyl-3-hexen-2-one to produce isobutyraldehyde and acetone; alpha-methyl-iso-ionone to produce citral and methyl ethyl ketone; 5-methyl-2-phenyl-2-hexenal to produce phenyl acetaldehyde and 3-methylbutanal; 4-phenyl-3-buten-2-one to produce benzaldehyde and acetone; and ortho-methoxy cinnamaldehyde to produce ortho-methoxy benzaldehyde and acetaldehyde.
(to be continued . . .)