JPH11116516A - Production of homoallyl alcohols - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject alcohol useful as a raw material for producing perfumes, medicines, agrochemicals, etc., industrially and advantageously, by bringing a specific compound into contact with γ-alumina in a vapor phase in a prescribed temperature range. SOLUTION: A compound of formula I (R<1> to R<6> , X and Y are each H, an alkyl, etc.) (e.g. 3-methyl-1,3-butanediol) is supplied to a container charged with γ-alumina having preferably 100 m<2> /g-250 m<2> /g specific surface area at the rate of 0.1-50 g/hr based on 1 cm<3> of γ-alumina, subjected to a catalytic reaction in a vapor phase at 140-250 deg.C and a product of formula II (one of A<1> and A<3> is H and the other forms a C-C bond with A<2> ) (e.g. 3-methyl-3-buten-1- ol) is continuously taken out to give the objective alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compound represented by the general formula (1):

[0002]

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(Wherein ^one of A ¹ and A ³ represents a hydrogen atom and the other forms a carbon-carbon bond with A ^2. R ¹ , R ² , R ³ , R ⁴ , R ^5, R ⁶ and Y
Represents a hydrogen atom, an alkyl group or an alkenyl group, respectively). The homoallyl alcohols represented by the general formula (1) produced by the method of the present invention are useful as raw materials for producing fragrances, medicines, agricultural chemicals and the like.

[0004]

2. Description of the Related Art Conventionally, as a method for producing a homoallylic alcohol represented by the general formula (1) using a compound represented by the general formula (2) such as 3-methyl-1,3-butanediol as a raw material, For example, the following methods are known. By dehydrating 3-methyl-1,3-butanediol under heating conditions in the presence of phosphoric acid or iodine, 3
Method for Obtaining -Methyl-3-buten-1-ol (Isopropenylethyl alcohol: IPEA) [Bull. Soc. C
him. Fr., 800-804 (1964)]. 3-Methyl-1,3-butanediol is contact-dehydrated in the liquid phase in the presence of alumina, silica alumina or calcium phosphate to give 3-methyl-3-butene-diol.
Method for obtaining 1-ol [Neftekhimiya, 3 , 104 (1963)
reference〕.

[0005]

However, since the above method uses phosphoric acid or iodine having high corrosivity, it is necessary to use an apparatus made of a material having sufficiently high corrosion resistance. Therefore, the cost required for the equipment increases. Further, when iodine is used as a catalyst, iodine having sublimability is easily mixed into the product, so that it is necessary to remove iodine from the product,
The manufacturing process becomes complicated. Also, in the above method,
In addition to the desired 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1 which is an allylic alcohol
-Ol is relatively large (3-methyl-3-butene-1-
(About 10 mol% with respect to all), resulting in poor selectivity. Thus, an object of the present invention is to provide an industrially advantageous method capable of highly selectively producing homoallylic alcohols represented by the general formula (1) without requiring a special apparatus.

[0006]

According to the present invention, the above object is achieved by the general formula (2)

[0007]

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Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R
⁶ , X and Y each represent a hydrogen atom, an alkyl group or an alkenyl group) in the gaseous phase at a temperature in the range of 140 ° C. to 250 ° C. with γ-alumina, General formula (1)

[0009]

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Wherein ^{one of} A ¹ and A ³ represents a hydrogen atom and the other together with A ² forms a carbon-carbon bond. R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and Y are as defined above).

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The general formula (2) representing the starting material used in the present invention and the general formula (1) representing the target compound
In the above, the alkyl group represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , X and Y is, for example, a methyl group,
Examples thereof include an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, and an isoamyl group, and preferably have 1 to 5 carbon atoms. Also, R ¹ , R
^2, the ^{R 3, R 4, R 5} , R 6, alkenyl radicals X and Y represents, for example, vinyl group, allyl group, propenyl group, isopropenyl group, 1-butenyl, 2-butenyl, 3 Examples thereof include -butenyl group, 3-methyl-2-butenyl group, and 3-methyl-3-butenyl group, but those having 1 to 5 carbon atoms are preferable. Here, specific examples of the compound represented by the general formula (2) used as a starting material in the present invention include 3-methyl-1,3-butanediol, 2,3-dimethyl-1,3-butane Diol,
2-methyl-2,4-pentanediol, 3-methyl-
3-methoxybutanol, 1-methoxy-3-methyl-
3-butanol, 3-methyl-1,3-dimethoxybutane, 3-methyl-1,3-pentanediol, 3-ethyl-1,3-pentanediol, 3-methyl-3-prenyloxy-1-butanol, 1-prenyloxy-3
-Methyl-3-butanol, 3,7-dimethyl-6-otadiene-1,3-diol and the like.

In the reaction according to the present invention, generally, a compound represented by the general formula (2) is supplied to a reaction vessel containing γ-alumina, and the compound is brought into contact with the surface of γ-alumina in a gas phase. It is carried out by continuously removing the obtained reaction product. The commercially available γ-alumina used in the present invention can be generally used. The form of γ-alumina is not particularly limited, and various forms such as powder, pellets, and extruded products can be used. Further, as γ-alumina, for example, silica or iron oxide of about 0.1% by weight or less,
A material containing an alkali metal oxide, a sulfate of 0.5% by weight or less, or the like may be used. The specific surface area of γ-alumina is preferably in a range from 100 m ² / g to 250 m ² / g, and is preferably from 150 m ² / g to 200 m ² / g.
More preferably, m ² / g.

The feed rate of the compound represented by the general formula (2) as a raw material is usually 0.1 to 100 per cm ³ of the catalyst.
g / hr, but from the viewpoint of the operability of the reaction and the yield of the homoallyl alcohol represented by the general formula (1), it is preferably 0.1 to 50 g / hr per 1 cm ^{3 of} γ-alumina. 0.5 per cm ^{3 of} γ-alumina
More preferably, it is 10 to 10 g / hr. Here, the volume of γ-alumina is not an apparent volume,
The true volume.

The reaction according to the invention needs to be carried out at a temperature in the range from 140 ° C. to 250 ° C. When the reaction temperature is lower than 140 ° C., the reaction rate is reduced and the productivity is impaired. When the reaction temperature is higher than 250 ° C., the loss due to thermal decomposition of the homoallylic alcohol represented by the general formula (1) increases. I do. The reaction according to the invention is between 160 and 2
It is preferably carried out at a temperature in the range of 40 ° C. The reaction according to the present invention may be performed under any of normal pressure, reduced pressure, and increased pressure, but is preferably performed under normal pressure or reduced pressure.

In the reaction according to the present invention, for example, the compound represented by the general formula (2) may be diluted using an inert gas such as nitrogen or argon as a diluent. Use diluents that are gaseous under the reaction conditions and do not adversely affect the reaction, such as saturated hydrocarbons such as pentane, hexane, cyclohexane, and heptane; and aromatic hydrocarbons such as benzene and toluene. Can also.
When a diluent is used, the amount of the diluent used is usually such that the concentration of the compound represented by the general formula (2) is 1% by volume or more, preferably 10% by volume or more.

In the present invention, a crude product can be obtained by cooling a gaseous reaction product obtained by the above-mentioned reaction. The crude product can be obtained by, for example, distillation using a distillation column. By purifying according to the conventional method, the homoallylic alcohol represented by the general formula (1), which is the target substance, can be easily separated and obtained. In addition,
The unreacted raw material recovered from the crude product is preferably used again as a starting material in the present invention.

[0017]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Example 1 γ-alumina (specific surface area: 170 m ² / g, N611N
3 (trade name), manufactured by JGC Chemicals, Inc.) 20 cm ³ (12.
6g) into a tubular reaction vessel (inner diameter 30mm, length 40c)
m), the internal temperature was raised to 215 ° C. under a normal pressure and a nitrogen stream, and the temperature was maintained at the same temperature for 60 minutes to stop the nitrogen stream. Then, at normal pressure, 3-methyl-1,3-butanediol is continuously supplied in a gaseous state at a rate of 60 g / hr to the reaction vessel to be brought into contact with γ-alumina, and the gaseous state taken out of the reaction vessel The reaction mixture was condensed by cooling to 5 ° C. and collected as a crude product. In this state, the reaction was carried out for 10 hours, and a total of 600 g (6.91 mol) was obtained.
597.4 g of a crude product was obtained from 3-methyl-1,3-butanediol. When the obtained crude product was analyzed under the following gas chromatography conditions, 3-methyl-
The conversion of 1,3-butanediol was 60.75%, the selectivity to 3-methyl-3-buten-1-ol was 82.7% (production amount: 249.54 g), and it was an allylic alcohol. The selectivity to prenol was found to be 1.2%. By distilling the obtained crude product under reduced pressure, 3-methyl-3-buten-1-ol (boiling point: 1
460 g (14 ° C./760 mmHg, purity: 99%) was obtained.

Gas Chromatography Analysis Conditions Column: CPB-10 (trade name, manufactured by GL Sciences), 0.25 μm (column diameter) × 50 m (length) Column temperature: After maintaining at 70 ° C. for 5 minutes, 5 ° C. The temperature was raised to 210 ° C. at a rate of / min.

Example 2 The same operation as in Example 1 was carried out except that the reaction temperature was changed to 225 ° C., and 597 g of a crude product were obtained from 600 g of 3-methyl-1,3-butanediol. .1
g was obtained. When the obtained crude product was analyzed by gas chromatography under the same conditions as in Example 1, the conversion of 3-methyl-1,3-butanediol was 67.9%, and 3-methyl-3 It was found that the selectivity to -buten-1-ol was 83.3% and the selectivity to allylic alcohol, prenol, was 1.1%.

Example 3 The same operation as in Example 1 was carried out except that the reaction time was changed to 300 hours.
17.9 kg of a crude product was obtained from -methyl-1,3-butanediol. The obtained crude product was analyzed under the same gas chromatography conditions as in Example 1 to find that
Conversion of methyl-1,3-butanediol is 61.3%
It was found that the selectivity to 3-methyl-3-buten-1-ol was 83.1%, and the selectivity to prenol, an allyl alcohol, was 1.2%.

Example 4 In Example 1, 2,3-dimethyl-1,3-butanediol was used in place of 3-methyl-1,3-butanediol at the same feed rate as in Example 1, and The same operation as in Example 1 was performed except that the reaction time was changed to 5 hours, to obtain 297 g of a crude product from a total of 300 g of 2,3-dimethyl-1,3-butanediol. When the obtained crude product was analyzed under the same gas chromatography conditions as in Example 1, the conversion of 2,3-dimethyl-1,3-butanediol was 61%, and the conversion of 2,3-dimethyl- The selectivity to 3-buten-1-ol was found to be 80.4%. The production of 2,3-dimethyl-2-buten-1-ol, which is an allylic alcohol, was not observed.

Example 5 The same operation as in Example 4 was carried out except that the reaction time was changed to 10 hours.
593 g of crude product was obtained from 3-dimethyl-1,3-butanediol. The obtained crude product was analyzed under the same gas chromatography conditions as in Example 1;
The conversion of 3-dimethyl-1,3-butanediol is 61
%, And the selectivity to 2,3-dimethyl-3-buten-1-ol was found to be 80.4%. In addition,
Production of 2,3-dimethyl-2-buten-1-ol, which is an allylic alcohol, was not observed.

[0023]

According to the present invention, homoallylic alcohols represented by the general formula (1) can be produced with higher selectivity than before.

Claims (1)

[Claims] 1. A compound of the general formula (2) (Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , X and Y each represent a hydrogen atom, an alkyl group or an alkenyl group). ~ 2
Contacting with γ-alumina at a temperature in the range of 50 ° C., comprising the general formula (1): Wherein ^one of A ¹ and A ³ represents a hydrogen atom and the other together with A ² forms a carbon-carbon bond.
¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and Y are as defined above).