JP2001335529A - Method for producing 2- (1-hydroxyalkyl) cycloalkanone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce 2- (1) from cycloalkanone and n-alkylaldehyde in good yield under a small amount of water and under mild conditions.
A method for obtaining (-hydroxyalkyl) cycloalkanone with high yield and high selectivity. SOLUTION: The cycloalkanone and n-alkyl aldehyde are subjected to aldol condensation in the presence of water and a base catalyst to give 2
In producing-(1-hydroxyalkyl) cycloalkanone, the amount of the base catalyst is set to 0.04 mol or less per 1 mol of n-alkylaldehyde. Manufacturing method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing 2- (1-hydroxyalkyl) cycloalkanone.
More specifically, the present invention relates to a method for efficiently producing 2- (1-hydroxyalkyl) cycloalkanone by subjecting cycloalkanone and n-alkylaldehyde to aldol condensation in the presence of a specific amount of a base.

[0002]

2. Description of the Related Art The utility of methyl jasmonate and methyl dihydrojasmonate is described in JP-A-56-14.
No. 7,740, page 2, upper left line 1 to upper right line 1, a valuable component useful as a pharmaceutical intermediate or a fragrance substance.
It is used to enhance and enhance the aroma of anionic, cationic or zwitterionic detergents or fabric softeners with added desiccant or colon.

One of the methods for synthesizing methyl jasmonate is disclosed in JP-A-56-147740, p.
Starting from cycloalkanone and aldehyde, an aldol derivative is obtained, which is dehydrated to an alkylidenecycloalkanone, and further subjected to a rearrangement reaction to obtain an alkylidene as described in line 13 to the upper left column, line 13 of line 7. A method is known in which a cycloalkenone is obtained, and a malonate-alkylcycloalkenone reaction product obtained by reacting the cycloalkenone with a malonate is obtained by demonocarboxylation.

[0004] In this series of reactions, the first aldol synthesis is carried out at a temperature of 20 to 50 ° C for about 30 minutes to 4 hours (preferably at about 30 ° C for about 1 hour). At this time, the molar ratio of cycloalkanone to aldehyde can be changed within a range of about 3: 1 to 1: 3,
1.8 moles of a ketone are preferable for 1 mole of the aldehyde, and the molar ratio of the base catalyst (for example, sodium hydroxide or the like) to the aldehyde is 1 mole for the aldehyde.
About 0.05 to 0.1 mol of a base catalyst (preferably 0.08
3 mol) (JP-A-56-147).
No. 740, page 5, lower right, 2 lines to page 6, upper left, 3 lines).

However, in this method, a large amount of water (in Example 1 of this publication, water 1
It is necessary to use 500 cc and 3.5 times as much water). Therefore, when the same production equipment is used, the amount of the target product per operation is smaller than when the amount of water used is small, and as a result, the production efficiency is poor.

[0006] Further, when the present inventors conducted a supplementary test according to the aldol synthesis reaction conditions disclosed in this publication, the yield of the intermediate aldol was about 80%,
The yield of alkylcycloalkenones obtained through isomerization is as low as about 57% based on the starting material, and a large amount of high-boiling impurities such as bimolecular adducts of aldehydes to cycloalkanone are generated. Therefore, a great deal of labor is required for the purification.

[0007]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to obtain an aldol compound from cycloalkanone and n-alkyl aldehyde with good yield under a small amount of water and under mild conditions. Another object of the present invention is to provide a method for obtaining an alkylcycloalkanone in a high yield.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that a base to be used in a reaction for obtaining an aldol form from a cycloalkanone and an n-alkylaldehyde is used. It has been found that if the amount is less than the specified amount, an aldol derivative can be obtained with a high yield and a high selectivity under mild conditions, and the present invention has been completed based on this finding.

According to the present invention, an aldol condensation of cycloalkanone and n-alkyl aldehyde in the presence of water and a base catalyst to produce 2- (1-hydroxyalkyl) cycloalkanone requires an amount of the base catalyst. The present invention relates to a method for producing 2- (1-hydroxyalkyl) cycloalkanone, wherein the amount is 0.04 mol or less per mol of n-alkyl aldehyde.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

As described above, the amount of the base catalyst used in the present invention is 0.1 to 0.1 mol per mol of n-alkyl aldehyde.
It is at most 04 mol, usually from 0.005 to 0.03 mol, preferably from 0.006 to 0.008 mol, particularly preferably from 0.007 mol. If the amount is too small, the reaction does not proceed. If the amount is too large, high-boiling by-products increase and the yield decreases.

The amount of water used for cycloalkanone is
Water in a weight ratio of 0.4 to 1.
5, preferably in a ratio of 0.45 to 0.9. If the proportion of water is too large, the production efficiency will deteriorate, and if the proportion of water is too small, the amount of high-boiling by-products will increase and the yield will decrease.

The molar ratio between the cycloalkanone and the n-alkyl aldehyde is not particularly limited, and it can be sufficiently used within the range described in JP-A-56-147740. The amount of cycloalkanone used per mole is usually 1.
It is suitably from 1 to 2.4 mol, preferably from 1.5 to 2.1 mol, particularly preferably from 1.7 to 1.9 mol. If the proportion of cycloalkanone is too large, the production efficiency tends to decrease, and if it is too small, the yield tends to decrease.

[0014] The reaction temperature is usually about 0 to 40 ° C, preferably about 15 to 30 ° C near room temperature. The lower the reaction temperature, the more the required amount of the base catalyst is required. If the temperature is too high, the generation of by-products (high-boiling products) increases, and the yield decreases.

The reaction time is usually 2.5 to 7.0 hours, preferably 3.5 to 4.5 hours (including the aldehyde addition time). Usually, an n-alkyl aldehyde is added dropwise to a system consisting of a cycloalkanone, a base catalyst and water,
It is preferable to stop the reaction about one hour after the completion of the dropwise addition.

The base catalyst used in the present invention has the following general formula:

## STR1 ## where M is an alkali metal such as Li, Na or K or an alkaline earth metal such as Mg, Ca or Ba;
Is an integer corresponding to 1 or 2. ) Is preferable.

The cycloalkanone used in the present invention is usually a 4- to 7-membered saturated aliphatic ketone, preferably a 5-membered cyclopentanone.

The n-alkyl aldehyde used in the present invention is preferably a monoaldehyde having 1 to 7 carbon atoms, including the carbon of the aldehyde group, particularly preferably 5 to 7 and particularly preferably 5.

The present invention is preferably performed in an inert gas atmosphere. Examples of the inert gas include nitrogen, argon, and the like.

The reaction of the present invention is carried out at an absolute pressure of 10 kPa to 1 kPa.
MPa, preferably 50 to 300 kPa, more preferably around 100 kPa.

Since the reaction of the present invention is a two-layer system reaction of cyclopentanone and water, a solvent that destroys this is not used. The solvent that can be used in combination is not particularly limited as long as it is an inert solvent in the reaction system and does not hinder the separation and purification of the product. As a specific example,
Examples thereof include aromatic hydrocarbons (such as benzene and toluene) and aliphatic hydrocarbons (such as nonane, decane and undecane) having a boiling point of about 140 to 210 ° C.

The alkylcycloalkenone obtained by dehydration and isomerization of the 2- (1-hydroxyalkyl) cycloalkanone thus obtained is reacted with a malonic acid diester. After the addition product is obtained, an alkyl (dihydro) jasmonate and a homolog thereof can be obtained by a series of steps by demonocarboxylation (Japanese Patent Application Laid-Open No. Sho 5).
No. 6, 147740, page 6, lower left column, line 1 to page 7, upper left column, line 13).

[0023]

EXAMPLES The present invention will now be described more specifically with reference to examples, but the present invention is not limited thereto. In the examples, "%" and "part" indicate "% by weight" and "part by weight", respectively, unless otherwise specified. Table 1 shows a comparison table of each example and comparative example.

The calculation of the yield, conversion and selectivity is as follows:
It is as follows. (1) Yield measurement method The aldol compound and the amount of pentylidenecyclopentanone produced by dehydration thereof are obtained by gas chromatography using decane as an internal standard substance, and the amount is calculated by the following formula based on these. . Yield (%) = [(moles of aldol compound formed + moles of pentylidenecyclopentanone formed) ÷ (moles of aldehyde used in reaction)] × 100 (2) Method for measuring conversion gas It calculates by the following formula using the peak area in chromatography. Conversion rate (%) = [(peak area of aldol form + peak area of pentylidenecyclopentanone) ÷ (peak area of aldol form + peak area of pentylidenecyclopentanone + peak area of aldehyde having 5 carbon atoms)] × 10
0 (3) Calculation method of selectivity The selectivity is calculated by the following formula. Selectivity (%) = (Yield / Conversion) × 100

[0025] Example 1 a mechanical stirrer, a thermometer, was placed N ₂ seal, the valeraldehyde dropping nozzle (added at low flow pump) 5
In a 00 ml four-necked flask, add cyclopentanone 151
g (1.8 mol), 76.4 g of water and 25 wt% Na
1.12 g of OH was added. 86.1 g (1 mol) of valeraldehyde was added dropwise to the obtained mixture over 2 hours and 30 minutes while maintaining the temperature at 25 ° C. After the addition, the reaction mixture was stirred at 25 ° C. for 1 hour. One hour later, the mixture was neutralized with a small amount of concentrated hydrochloric acid. After separation, the organic layer was analyzed by gas chromatography. As a result, 148.6 g of 2- (1-hydroxy-n-pentyl) cyclopentanone was obtained (yield: 87). .4%). Both conversion and selectivity are shown in Table 1.

[0026] Example 2 a mechanical stirrer, thermometer, N ₂ seal, the valeraldehyde dropping nozzle (added at low flow pump) placed 5
In a 00 ml four-necked flask, add cyclopentanone 151
g (1.8 mol), 72.7 g of water and 25 wt% Na
4.8 g of OH were added. 86.1 g (1 mol) of valeraldehyde was added dropwise to the obtained mixture over 2 hours and 30 minutes while maintaining the temperature at 25 ° C. After the addition, the reaction mixture was
Stirred at 5 ° C for 1 hour. One hour later, the mixture was neutralized with a small amount of concentrated hydrochloric acid. After separation, the organic layer was analyzed by gas chromatography. As a result, 141.3 g of 2- (1-hydroxy-n-pentyl) cyclopentanone was obtained (yield: 83). .1%). Both conversion and selectivity are shown in Table 1.

[0027] Example 3 a mechanical stirrer, a thermometer, was placed N ₂ seal, the valeraldehyde dropping nozzle (added at low flow pump) 5
In a 00 ml four-necked flask, add cyclopentanone 151
g (1.8 mol), 127.5 g of water and 25 wt% N
1.52 g of aOH was added. 86.1 g (1 mol) of valeraldehyde was added dropwise to the obtained mixture over 2 hours and 30 minutes while maintaining the temperature at 25 ° C. After the addition, the reaction mixture was stirred at 25 ° C. for 1 hour. One hour later, the mixture was neutralized with a small amount of concentrated hydrochloric acid. After separation, the organic layer was analyzed by gas chromatography. As a result, 153.7 g of 2- (1-hydroxy-n-pentyl) cyclopentanone was obtained (yield: 90). .4%). Both conversion and selectivity are shown in Table 1.

[0028] Example 4 a mechanical stirrer, thermometer, N ₂ seal, the valeraldehyde dropping nozzle (added at low flow pump) placed 5
In a 00 ml four-necked flask, add cyclopentanone 17
6.7 g (2.1 mol), water 122.8 g and 25 w
6.24 g of t% NaOH was added. 86.1 g (1 mol) of valeraldehyde was added to the obtained mixture at 25 ° C.
The solution was added dropwise over 2 hours and 30 minutes while maintaining the temperature. After the addition, the reaction mixture was stirred at 25 ° C. for 1 hour. One hour later, the mixture was neutralized with a small amount of concentrated hydrochloric acid. After separation, the organic layer was analyzed by gas chromatography. As a result, 159.3 g of 2- (1-hydroxy-n-pentyl) cyclopentanone was obtained (yield: 93). .
7%). Both conversion and selectivity are shown in Table 1.

Comparative Example 1 16.5 g of sodium hydroxide was placed in a 5 liter reaction flask equipped with a mechanical stirrer, a 500 ml dropping funnel, an immersion thermometer, a reflux condenser and a 5 liter heating mantle, and a dry ice / isopropyl alcohol bath. And 15
00 cc of water was added. The resulting mixture was warmed to 30 ° C. While maintaining the reaction temperature at 30 ° C. in a dry ice / isopropanol bath, 756 g (9.0 mol) of cyclopentanone was added dropwise with stirring over 15 minutes. Next 43
0 g (5.0 mol) of n-valeroaldehyde at a temperature of 3
The solution was added dropwise over 40 minutes while stirring at 0 ° C. After the addition, the reaction mixture was stirred at 30 ° C. for 1 hour. One hour later,
30.0 g of acetic acid was added using a dropping pipette, and the organic layer was analyzed by gas chromatography. As a result, 2-
(1-hydroxy-n-pentyl) cyclopentanone was obtained in a yield of 80.6%. Both conversion and selectivity are shown in Table 1.

[0030]

[Table 1]

[0031]

According to the present invention, 2- (1) is obtained in a good production efficiency using cycloalkanone and saturated aliphatic aldehyde as raw materials, that is, in the presence of a low-concentration catalyst, with high yield.
-Hydroxyalkyl) cycloalkanone can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Miki 2-1-1, Yakko, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Zeon Corporation General Development Center (72) Inventor Keita Nakano Shio Kojima, Kurashiki-shi, Okayama Prefecture 2767-1 character Zeon Co., Ltd. ZEON Corporation Mizushima Plant F-term (reference) 4H006 AA02 AC46 BA02 BA28 BA29 BA69 BB31 BB61 BC34 4H039 CA60 CF30

Claims (2)

[Claims] An aldol condensation of cycloalkanone and n-alkyl aldehyde in the presence of water and a base catalyst to give 2
In producing-(1-hydroxyalkyl) cycloalkanone, the amount of the base catalyst is set to 0.04 mol or less per 1 mol of n-alkylaldehyde. Manufacturing method. 2. The use amount of water to cycloalkanone is 0.4 to 1.5 in weight ratio to cycloalkanone.
The 2- (1-hydroxyalkyl) according to claim 1, which is
A method for producing cycloalkanone.