Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2001-09-26
2002-06-18
Barts, Samuel (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S822000, C568S831000
Reexamination Certificate
active
06407293
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a process for producing 3-1-menthoxypropane-1,2-diol useful as a cooling agent and a refrigerant, and to a 3-1-menthoxypropane derivative useful as an intermediate for producing 3-1-menthoxypropane-1,2-diol and a process for producing the same. According to the invention, highly pure 3-1-menthoxypropane-1,2-diol and 3-1-menthoxypropane derivatives useful as synthetic intermediates for 3-1-menthoxypropane-1,2-diol can be obtained safely and in high yields through simple operations.
BACKGROUND ART
3-1-Menthoxypropane-1,2-diol is a known compound as described in Japanese Patent Publication No. 48813/1986. 3-1-Menthoxypropane-1,2-diol is excellent in safety and also have a nature of imparting a cooling effect on skin and mucous membrane like 1-menthol. On the other hand, it is odorless unlike 1-menthol, and itself has no smell. Therefore, in the case of using 3-1-menthoxypropane-1,2-diol, a cooling effect can be imparted to a product without affecting the fragrance imparted to the product. Thus, utilizing the above characteristic of 3-1-menthoxypropane-1,2-diol, 3-1-menthoxypropane-1,2-diol has been blended with oral compositions such as tooth paste and chewing gum, and food and drink such as sherbet and hard candies, and further, it has been proposed to blend it with toilet articles such as cosmetics (Published Japanese Patent Application Nos. 25908/1985 and 208505/1988), an eye-pack agent (Published Japanese Patent Application No. 96403/1987) and a hair cosmetic (Published Japanese Patent Application No. 192312/1987), and others such as an aerosol composition for anti-inflammatory agents (Published Japanese Patent Application No. 264522/1988).
Processes for producing 3-1-menthoxypropane-1,2-diol which are known heretofore include (i) a process wherein 1-menthol is converted to the sodium salt with metal sodium or sodium hydride, then an allyl halide is reacted therewith to produce 3-1-menthoxypropan-1-ene, and it is oxidized using an organic peroxide to form an oxide, followed by hydrolysis (Japanese Patent Publication No. 48813/1986), and (ii) a process wherein 1-menthol is added to benzyl glycidyl ether in the presence of a Lewis acid to produce 1-benzyloxy-3-1-menthoxypropan-2-ol and it is subjected to hydrogenolysis in the presence of palladium-carbon catalyst to eliminate the benzyl group (Published Japanese Patent Application No. 82200/1995).
However, in the above conventional method (i), sodium salt of 1-menthol is produced with metal sodium or sodium hydride, and therefore there are problems of the risk of explosion and the generation of hydrogen gas. Furthermore, an intermediate of 3-1-menthoxypropan-1-ene is oxidized with an organic peroxide, and thus the risk of explosion also exists at the use. Accordingly, the process is not regarded as an industrially advantageous one and also some improvement is required from an economical point of view.
Moreover, since the above conventional process (ii) is a process for the purpose of synthesizing an optical isomer, it is necessary to use expensive benzyl glycidyl ether. In addition, 3-1-menthoxypropane-1,2-diol finally obtained contains about 10% of 2-1-menthoxypropane-1,3-diol as a by-product, so that the purification or fractionation by silica gel column chromatography or the like is necessary and thus it is difficult to obtain a large amount of highly pure 3-1-menthoxypropane-1,2-diol.
Furthermore, other than the above conventional processes, proposed is (iii) a process wherein 1-menthol is added to a 1,2-epoxy-3-halogenopropane such as epichlorohydrin in an aqueous solution in the presence of a base and a quaternary ammonium salt to produce 1,2-epoxy-3-1-menthoxypropane which is a synthetic intermediate for 3-1-menthoxypropane-1,2-diol [French Patent No. 2479822 (1981)]. However, 1,2-epoxy-3-halogenopropane such as epichlorohydrin is known to be unstable and prone to decompose in the presence of an acid or a base [“Kagaku Daijiten”, p. 292, published by Tokyo Kagaku Dojin (1989)]. Therefore, in the case of this process where a 1,2-epoxy-3-halogenopropane is reacted in the presence of a base, the 1,2-epoxy-3-halogenopropane decomposes when the reaction takes a long period of time, so that it is difficult to synthesize 1,2-epoxy-3-1-menthoxypropane, and thus this process is not regarded as an advantageous process from industrial and economical viewpoints.
Furthermore, as the reaction between epichlorohydrin and an alcohol, proposed is (iv) a process for producing 1-allyloxy-3-chloro-2-propanol by reacting epichlorohydrin with allyl alcohol in the presence of an acidic catalyst (Published Japanese Patent Application No. 221/1990). In this conventional process (iv), however, the alcohol to be used in the reaction is only primary allyl alcohol and the application to a secondary alcohol, much less the addition reaction with menthol, is not reported.
In addition, as another conventional process, there is proposed (v) a process wherein an epihalohydrin is reacted with an alcohol in the presence of an acid catalyst, then the product is treated with an alkali to form a glycidyl ether through ring closure, and after hydrolysis, the reaction mixture is heated at 100 to 230° C. in the presence of a salt formed from a strongly basic compound and a weakly acidic compound to produce a glycerol ether (Published Japanese Patent Application No. 212114/2000). However, in order to decompose an organohalogen contained in hydrolyzate of the glycidyl ether, this process requires heating the reaction mixture at a high temperature of 100 to 230° C., especially 150 to 200° C. in the presence of a salt formed from a strongly basic compound and a weakly acidic compound, and thus is not an efficient process. Furthermore, the alcohol to be used in the process is a primary alcohol represented by the general formula: R—(OA)
p
—OH (wherein R represents a saturated or unsaturated linear or branched hydrocarbon group having 1 to 36 carbon atoms, A represents an alkylene group having 2 to 4 carbon atoms, and p represents one number of 0 to 100), and the use of secondary alcohol is not disclosed, much less the use of menthol is not disclosed at all.
An object of the invention is to provide a process for producing highly pure 3-1-menthoxypropane-1,2-diol safely and in high yields through simple operations.
Other object of the invention is to provide an intermediate useful for obtaining highly pure 3-1-menthoxypropane-1,2-diol.
Still other object of the invention is to provide a process for producing intermediates useful for obtaining 3-1-menthoxypropane-1,2-diol efficiently.
SUMMARY OF THE INVENTION
The present inventors have extensively studied for achieving the above objects. As a result, a novel compound of a 1-halogeno-3-1-menthoxypropan-2-ol can be produced by adding 1-menthol to a 1,2-epoxy-3-halogenopropane in an organic solvent in the presence of a Lewis acid. And, as a result of further studies, they have found that the novel 1-halogeno-3-1-menthoxypropan-2-ol is chemically stable and can be stored by itself, and 1,2-epoxy-3-1-menthoxypropane, which is also an intermediate for obtaining 3-1-menthoxypropane-1,2-diol, is obtained at a high reaction rate and in high yields by further epoxidating the 1-halogeno-3-1-menthoxypropan-2-ol with a base in the presence of a phase transfer catalyst, and objective 3-1-menthoxypropane-1,2-diol is obtained conveniently in good yields and at a high purity by hydrolyzing the 1,2-epoxy-3-1-menthoxypropane. Based on these findings, they have accomplished the invention.
Namely, the invention relates to:
(1) a process for producing 3-1-menthoxypropane-1,2-diol, which comprises:
adding 1-menthol to a 1,2-epoxy-3-halogenopropane represented by the following general formula (I):
(wherein X represents a halogen atom),
in an organic solvent in the presence of a Lewis acid to produce a 1-halogeno-3-1-menthoxypropan-2-ol represented by the following general formula (II):
(wherein X represents a halogen atom),
then, epoxidating it with a base in the pres
Akiyama Teruyoshi
Amano Akira
Hagiwara Toshimitsu
Miura Takashi
Barts Samuel
Fitzpatrick ,Cella, Harper & Scinto
Price Elvis O.
Takasago International Corporation
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