JPS5930697B2 - Production method of β-cyclohexylpropionate - Google Patents

Description

Detailed Description of the Invention The present invention obtains γ・γ-pentamethylene butyrolactone from cyclohexanol and acrylic ester, and then hydrogenates and esterifies it to obtain β=
The present invention relates to a method for producing cyclohexylpropionate.

β-Cyclohexylpropionate ester occupies an important position as a pie apple-based fragrance, and its conventional manufacturing method involves obtaining cinnamic acid from benzaldehyde, acetic anhydride, and sodium acetate through the Perkin reaction, and then hydrogenating this. , Method of esterification [JACS, 5
0, 3333 (1928)] or heating hexahydrobenzylmalonic acid to obtain β-cyclohexylpropionic acid, which is then esterified [JA
CS, Kuchi, 2391 (1926)] have been reported. However, in order to obtain the cinnamic acid or hexahydrobenzylmalonic acid used in the above method, complicated and complicated steps are required, and the method is not necessarily satisfactory as an industrial production method.

Therefore, the present inventors conducted intensive studies on a method for obtaining β-cyclohexylpropionic acid ester through a simplified process using easily available starting materials, and as a result, they arrived at the present invention. That is, the present invention provides (I) a step of producing γ, γ-pentamethylene butyrolactone by reacting cyclohexanol and an acrylic ester in the presence of an organic peroxide; A step of hydrogenating β=cyclohexylpropionic acid in the gas phase in the presence of a platinum group metal catalyst:
(a step of reacting β-cyclohexylpropionic acid and alcohol to produce β-cyclohexylpropionic ester).

Next, the method of the present invention will be explained in detail by dividing into each step.

(1) Step Cyclohexanol and acrylic ester are reacted in the presence of an organic peroxide to obtain γ·γ-pentamethylene butyrolactone.

The reaction proceeds according to the following formula (I).

(In the formula, R1 represents an alkyl group having 1 to 8 carbon atoms.) There is no particular restriction on the ratio of cyclohexanol and acrylic acid used, and the two react in equimolar amounts in stoichiometric terms. do.

As acrylic esters, methyl acrylate, ethyl acrylate, propyl acrylate, ethyl acrylate,
Examples include hexyl acrylate and octyl acrylate.

- Generally, when using an acrylic ester having an alkyl group with a large number of carbon atoms in R1, the yield of the target product tends to improve. Examples of organic peroxides include ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, and cyclohexanone peroxide, diacyl peroxides such as acetyl peroxide, propionyl peroxide, and lauroyl peroxide, and t-butyl hydroperoxide. Oxides, such as cumene hydroperoxide:
Examples thereof include hydroperoxide, di-t-butyl peroxide, dialkyl peroxide such as dicumyl peroxide, and the like.

The ratio of peroxide used is 1 part of the raw acrylic ester.
A suitable amount is 0.01 to 0.2 mole. Although it is not necessary to use a particular solvent for this reaction, a solvent that is not susceptible to hydrogen abstraction, such as benzene, may be used in some cases.

The reaction temperature is suitably in the range of 150 to 180°C.

The γ·γ-pentamethylene butyrolactone obtained by this reaction is separated and obtained by conventional operations such as distillation and extraction.

(11) Step γ/γ-pentamethylene butyrolactone is hydrogenated in the gas phase in the presence of a platinum group metal catalyst to obtain β-cyclohexylpropionic acid.

The reaction proceeds according to the following formula (n.

As platinum group metal catalysts, platinum, palladium, rhodium,
These metals include ruthenium, osmium, and iridium, or compounds of these metals, and two or more of these metals may be used in combination.

Here, the metal compounds include rogens, hydroxides, oxides, carboxylates, nitrates, etc. These metals or metal compounds are treated in a reducing atmosphere before or during the reaction. These metals or metal compounds may be used alone, or may be supported on a porous material such as alumina, activated carbon, silica, diatomaceous earth, or the like. The amount of catalyst component supported is 0.5 to 20% by weight.
is appropriate. The hydrogen used is pure hydrogen or a hydrogen-containing gas obtained by diluting hydrogen with an inert gas such as nitrogen or helium.

The reaction is carried out in a gas phase, at a temperature in the range of 200 to 300° C., and in general, normal pressure is sufficient, but low elevated pressure or low reduced pressure is also applicable.

Generally, this reaction is carried out in a catalyst bed filled with a platinum group metal catalyst.
This is carried out by passing vaporized γ/γ-pentamethylene butyrolactone together with a hydrogen-containing gas, and the target product β-cyclohexylpropion group, β
- Cyclohexylidenepropionic acid and unreacted lactone are obtained.

Therefore, β-
Cyclohexylpropionic acid is separated and obtained. Note that β-cyclohexylidenepropionic acid is a precursor,
Further hydrogenation converts it to β-cyclohexylpropionic acid. 11) Step β-cyclohexylpropionic acid and alcohol are reacted to obtain β-cyclohexylpropionic acid ester.

The reaction proceeds according to the following formula (11).

(In the formula, R2 represents an alkyl group or an allyl group having 1 to 4 carbon atoms.) There is no particular restriction on the proportion of β-cyclohexylpropionic acid and alcohol used, and both are stoichiometrically React with equimolar amounts.

Examples of the alcohol include methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, and allyl alcohol. In particular, allyl β-cyclohexylpropionate obtained when allyl alcohol is used is useful as a pineapple-based perfume. In addition, when using a saturated aliphatic alcohol as the alcohol, the alcohol by-produced during the production of γ, γ-pentamethylene butyrolactone from the reaction of cyclohexanoyl and alkyl acrylate in step 1 is recovered. Sulfuric acid, hydrochloric acid, toluenesulfonic acid, etc. are usually used as the esterification catalyst.

The reaction temperature is in the range of 80 to 100°C.

As described above, by carrying out the method of the present invention, γ・γ-pentamethylene butyrolactone is obtained from cyclohexanol and acrylic ester, hydrogenated to obtain β-cyclohexylpropionic acid, and then esterified. The desired product, β-cyclohexylpropionate, can be produced through these steps.

Riding example! ) Process details 287 parts of cyclohexanol (hereinafter referred to as parts by weight) was charged into a 500 ml stainless steel reactor, heated to 160°C, and 49 parts of methyl acrylate was added to the reactor.

A mixture of 4 parts and 8.4 parts of di-t-butyl peroxide was fed over 6 hours.

Transfer the reaction solution to a distillation column, add 2 cyclohexanol to the unreacted
After collecting 07 parts, 74 parts of r.gamma.-pentamethylene butyrolactone was heated at 136°C/10m7! Distilled with LHg.
The yield based on the reacted cyclohexanol was 93%. 11) 11 in the process catalyst layer? , a stainless steel reaction tube filled with platinum-alumina was heated to 250°C, and hydrogen was added to it at 200°C.
γ·γ-pentamethylene butyrolactone was supplied at a flow rate of 200 ml/Hr.

The reaction solution was transferred to a distillation column, and β-cyclohexylpropionic acid and β-cyclohexylidenepropionic acid were distilled out at 145°C/10m711Hg and 154°C/10mmHg, respectively.

The conversion rate of γ・γ-pentamethylene butyrolactone is 91
%, and the selectivity of β-cyclohexylpropionic acid with respect to the lactone was 69%, and the selectivity of β-cyclohexylidenepropionic acid was 20%. Note that this β
-Cyclohexylidenepropionic acid was further hydrogenated and converted to β-cyclo-xylpropionic acid in a yield of 63%. (Iiii) Process details 20 parts of β-cyclohexylpropionic acid, 76 parts of allyl alcohol, and 1 part of concentrated sulfuric acid are charged into a 100 ml stainless steel reactor, and after heating under reflux for 3 hours, water is distilled off by azeotropy, and allyl alcohol is removed. It was recovered by distillation.

Claims (1)

[Claims] 1 (i) Step of producing γ・γ-pentamethylene butyrolactone by reacting cyclohexanol and acrylic ester in the presence of an organic peroxide: (ii) γ・γ
- Hydrogenating pentamethylene butyrolactone in the gas phase in the presence of a platinum group metal catalyst to produce β-cyclohexylpropionic acid; (iii) Reacting β-cyclohexylpropionic acid with an alcohol to produce β-cyclohexylpropionic acid; 1. A method for producing β-cyclohexylpropionate, the method comprising: producing an acid ester.