JPS60246340A - Preparation of 3-methyl-2-buten-1-ol - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as an intermediate for citral, etc., by bringing prenol in the vapor phase into contact with O2 in the presence of a catalyst containing silver, copper and a basic metal oxide supported on a carrier having a specific surface area to carry out the oxidative dehydrogenation. CONSTITUTION:3-Methyl-2-buten-1-ol (prenol) in the vapor phase and molecular oxygen are subjected to oxidative dehydrogenation in the presence of a catalyst containing three components of silver, copper (preferably at 99:1-50:50 weight ratio) and a basic metal oxide (preferably 0.01-0.5wt% based on the carrier) supported on a carrier having <3m<2>/g specific surface area, preferably quartz, molten alumina or molten silica, at 300-600 deg.C, preferably 400-500 deg.C to give the aimed 3-methyl-2-buten-1-al (senecioaldehyde). USE:A synthetic intermediate for citral, beta-ionone and chrysanthemumic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for producing 3-methyl-2-buten-1-al.

[Technical background of the invention and its problems]

Conventionally, 3-methyl-2-buten-1-ol (hereinafter referred to as prenol) is dehydrogenated from K by contacting it with an oxidative dehydrogenation catalyst in the gas phase to produce 3-methyl-2-buten-1-al (hereinafter referred to as prenol). , senecioaldehyde) is known.

For example, JP-A-53-137906 discloses that in producing 3-alkyl-buten-1-al such as senecioaldehyde by oxidative dehydrogenation of alkenol such as prenol through a catalyst with oxygen,
characterized by the use of a multilayer catalyst with button and/or copper particles consisting of two or more layers of particles each with a constant weight and a constant particle size having a constant total layer thickness; A method for producing the above 3-alkyl-buten-1-al is described. However, the catalyst used in this method contains silver and/or copper in the form of particles and has a special layer structure, so it is not easy to make it from PA on an industrial scale. U.S. Pat. No. 2,042,220 also describes a method for producing the corresponding unsaturated aliphatic aldehydes by oxidizing unsaturated aliphatic alcohols with oxygen at elevated temperatures in the presence of an oxidation catalyst. is listed. In this method, it is considered appropriate to use an activated oxidation catalyst. For example, a copper oxide wire is heated at 300°C in a hydrogen atmosphere.
Copper catalysts prepared by reducing the mercury at is difficult to employ.

Furthermore, in the specification of German Patent No. 2041976, prenol is added to copper, silver, and
In the presence of a dehydrogenation catalyst such as zinc, and in the presence of a nuclear aliphatic or aromatic organic nitrogen compound, a sulfur compound for phosphination, or ammonia gas, and/or the dehydrogenation catalyst Basic golds such as barium oxide, calcium oxide, and magnesium oxide as additives to dehydrogenation catalysts as carriers of the glands J! A method for producing C senecioaldehyde by dehydrogenation in the presence of .ji oxide is disclosed. It has been pointed out that in this method, when oxygen is present, the oxidation of prenol proceeds too much and the amount of dimethylacrylic acid produced increases, resulting in a significant decrease in the yield of senecioaldehyde.

[Purpose of the invention]

An object of the present invention is to solve the problems of the conventional methods as described above and to provide an improved production method for producing senecioaldehyde by contacting prenol with an oxidative dehydrogenation catalyst in the gas phase together with oxygen. .

[Structure of the invention]

The present invention uses prenol in the gas phase at a temperature of 300 to 600°C with molecular oxygen, and has a specific surface area of 31t+//f.
'Silver and steel and basic gold I! The present invention relates to a method for producing senecioaldehyde, which comprises bringing it into contact with a catalyst formed by supporting three components of a tetradisperse.

[Detailed description of the invention]

The catalyst used in the method of the present invention has three components, silver, copper, and a basic metal oxide, supported on a carrier having a specific surface area of less than 3V2 as measured by the BET method.

The specific surface area of the carrier used must be less than K 3 rrl, # in order to obtain senecioaldehyde with good selectivity,
Special K 1 n? It is preferable that it is less than /f. If the specific surface area of the carrier is large, side reactions occur and large amounts of isobutyne, isoprene, etc. are produced as by-products. As a carrier, quartz sand 1 fused alumina, fused silica, silicon carbide, hydroxyapatite [calo(Po4)6(oH)2], pumice, etc. having a small specific surface area as described above are used. By using such a support, in addition to being able to increase the selectivity to senecioaldehyde, the effective surface area of the catalyst increases compared to when no support is used, and a large activity can be achieved with a small amount of catalytic elements. What can be obtained 1. It is advantageous for dispersing and removing the reaction heat, suppressing the nintering of the catalyst metal component due to local overheating during reaction and activation, stabilizing the fine structure of the active part, and reducing the amount of reaction gas. Advantages of industrial engineers arise, such as the ease with which they can respond to a wide range of changes. In addition, it is preferable to use a carrier with a small amount of acid (17) in order to improve the selectivity to senecioaldehyde; for example, the value measured by amine titration is
Those having an acid content of XI Q rnmol /7 or less are suitable.

The weight ratio of silver and copper supported on the above carrier is 99:1
The range of 50 to 5o is preferable, especially 98 to 2 to 9
A range of 0:10 is preferred. The total weight of silver and steel supported on the carrier is from 01 to 30% by weight, preferably from 1 to 15% by weight. It is preferable to use a catalyst with a small amount of silver and copper supported in order to reduce the catalyst cost, but if the amount supported is less than 0.1% by weight, the conversion rate of prenol and the selectivity to senecioaldehyde will decrease. Preference 2: No. On the other hand, if the supported amount exceeds 3011j, the catalytic effect commensurate with the excess amount will not be obtained and the cost of the catalyst will increase, so it is not preferable to use it industrially. If a catalyst is used in which either silver or steel is not supported, both the conversion of prenol and the selectivity to senecioaldehyde are reduced. As the basic metal oxide, any metal oxide that exhibits basicity can be used, but oxides of alkaline earth metals such as magnesium oxide, calcium oxide, and barium oxide are particularly preferred. The amount of basic metal oxide supported is suitably in the range of 0.01 to 0.05 times the weight of the carrier.

The oxidative dehydrogenation catalyst used in the method of the present invention can be prepared by impregnating the above-mentioned carrier with a mixed aqueous solution of silver nitrate, steel nitrate, and nitrates of metals forming the basic metal oxides in predetermined amounts. It can be easily prepared by calcination in air at a temperature of 400°C followed by treatment with hydrogen at a temperature of about 300-500°C. The catalyst bed used in carrying out the present invention is suitably a fluidized bed or a multi-tubular fixed bed.

The oxidative dehydrogenation reaction in the present invention is carried out in the gas phase at 300 to 600
C, preferably within a temperature range of 400 to 500C. It is necessary to set the maximum temperature of the catalyst layer to be within this temperature range.

At temperatures lower than 300°C, the yield of senecioaldehyde per unit volume of the catalyst becomes small, and at temperatures above 600°C, side reactions occur significantly, shortening the active life of the catalyst. This oxidative dehydrogenation reaction is an exothermic reaction, and in order to maintain the temperature of the catalyst layer within the above temperature range, it is necessary to remove heat by an appropriate method. Heat removal methods include, for example, cooling the reaction zone (catalyst layer) from the outside with a suitable heating medium, and simultaneously reacting with the feed gas of prenol as a raw material and inert gas of approximately 0.5 to 2 times the volume of the feed gas. It is possible to adopt a method of supplying the product to the area or a method of using these methods in combination. Suitable inert gases to be used include nitrogen, helium, water vapor, and the like, which do not have an adverse effect on the raw material prenol, the catalyst, and the like.

In addition, in the catalyst used in the method of the present invention, in order to increase the heat transfer area and facilitate heat removal, the catalyst is supported on a support such as glass beads, quartz sand, molten alumina, or a carrier supporting a basic metal oxide. It can also be diluted with active particles.

The molecular oxygen used in the oxidative dehydrogenation reaction in the present invention may be diluted with nitrogen, argon, helium, water vapor, or the like. Specifically, it is convenient to use air. It is preferable to use molecular oxygen in an amount less than the stoichiometric amount relative to prenol, and specifically, it is appropriate to use an amount of about 0.4 mol or less, particularly 0.2 to 0.4 mol, per 1 mol of prenol. As the ratio of molecular oxygen to prenol increases, the conversion rate of prenol increases, but the selectivity to senecioaldehyde decreases and it becomes difficult to remove the heat of reaction.

The amount of prenol supplied to the reaction zone is LH8V (liquid volume of prenol supplied per hour per unit volume of catalyst)
A range of about 0.5 to 60 hours is appropriate. Within this range, if the usage ratio with molecular oxygen is the same, LH8V
The selectivity to senecioaldehyde tends to increase as the
It is preferable to select LH8V from within the range. However, when attempting to obtain a higher space-time yield (STY), a higher value of LH8V can be adopted. The residence time of the reaction gas on the catalyst is preferably 1 second or less.

Separation and recovery of senecioaldehyde from reaction product gas is
For example, this can be easily carried out by cooling the reaction product gas and distilling the condensate.

The senecioaldehyde produced by the method of the present invention is useful as a synthetic intermediate for, for example, citral, β-yono/chrysanthemum acid, and the like.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 Fused alumina (manufactured by Twotone, 5A-5221, 1/8
"Spherical shape, specific surface area measured by BET method: 85 d), 41.7 d of copper nitrate, 11.2 ffi of cupric nitrate trihydrate, 1 ffi of magnesium nitrate hexahydrate The sample was immersed in a mixed aqueous solution 100*e consisting of .87 heavy sugar and 453% by weight of water, and after removing the excess mixed aqueous solution by tecanation, it was dried under reduced pressure at 150°C for 3 hours. 300 *e/mi
Baked for 4 hours under air circulation at 7, then heated to 350~4
Reduction was carried out at 50° C. for 5 hours under hydrogen flow of 500 m/min]7. In this way, the weight ratio of steel and magnesium oxide in the lpl-manufactured catalyst is 9:1:012, the total weight of aluminum and copper supported on fused alumina is 120% by weight, and the relative weight of magnesium oxide is 9:1:012. is 0
It was 14% by weight.

- After heating the catalyst 701/ prepared as described in F above to 300° C. in a glass WK container having an inner diameter of 20 mm.

Add prenol to this catalyst layer LH8V5. Ohr and at the same time air was fed at a rate of 1.31 J/min (oxygen to prenol molar ratio 02). Four hours after the start of supply, the reaction reached a steady state, and the highest temperature of the catalyst layer was 450°C.

When the reaction solution obtained during the 1 hour period from 4 hours to 5 hours was quantified by gas chromatography using an internal standard method, the conversion rate of prenol was 37.91, indicating that the conversion rate to sene/oaldehyde was 37.91. The selectivity was 96.6 molar. In addition to senecioaldehyde, trace amounts of isopre/invaleral and 3-methyl-3-butene-1-al were produced as by-products.

A 15% aqueous sodium carbonate solution 14.2 F (equivalent to the amount of acid determined by acid titration of the reaction solution) was added to a portion (142 oy) of the resulting reaction solution, and water was added under reduced pressure of 200 to 100 wHr. After the extraction, the temperature of the distillation bottom is 1.
By distilling under reduced pressure not exceeding 00℃, the boiling point is 6.
Senecioaldehyde was extracted as a fraction at 0°C and 150mHr.
Obtained 67.9F (purity +99.5, distillation recovery rate: 99
0chi).

Examples 2 to 3 and Comparative Example 1 *, m The reaction was carried out in the same manner as in Example 1 except that the weight of magnesium oxide relative to alumina was changed. The reaction solution was quantitatively determined in the same manner as in Example 1, and the reaction results are shown in Table 1 together with those in Example 1.

Table 1 Note that in Comparative Example 1, a large amount of inbrene was produced as a by-product (selectivity of 6.7 mol%), but in Examples 1 to 3, a trace amount of isoprene was produced as a by-product (selectivity of 1 to 2 mol%). I didn't like it.

Examples 4 to 5 The reaction was carried out in the same manner as in Example 1 except that the basic gold ellipoxide was changed.The reaction solution was quantified in the same manner as in Example 1, and the reaction results were evaluated. It is shown in Table 2 together with that of Example 1.

Table 2 Examples 6 to 9 Catalysts prepared in the same manner as in Example 1 or those diluted with six different diluents were used, and Vc on these catalysts was
Prenol was supplied at 352 vrl/hr and air was simultaneously supplied at 78.46 vrl/hr (oxygen molar ratio to prenol °
The reaction was carried out in the same manner as in Example 1 except that 03) was supplied.The reaction solution was quantified in the same manner as in Example 1,
The reaction results are shown in Table 3.

Examples 10 to 13 and Comparative Examples 2 to 3 The total weight of silver and/or copper to fused alumina was kept at 12.0% by weight, and the weight of magnesium oxide was kept at 0.14 weight%. The reaction was carried out in the same manner as in Example 1, except that catalysts were used with different weight ratios of silver and steel. The reaction solution was quantitatively determined in the same manner as in Example 1, and the reaction results are shown in Table 4 together with those in Example 1.

Table 4 Note that in Comparative Examples 2 and 3, a large amount of isobutyne and isogrene were produced as by-products (selectivity 5 to 12 mol%), but in Example 10
~13, isobutine and imprene are trace amounts (selectivity 1
Only ~2 mol of by-product was produced.

Examples 14 to 17 and Comparative Examples 4 to 5 Catalysts prepared in the same manner as in Example 1 using various carriers [weight ratio of chime to steel: 9:1, total supported M amount of chime and copper to the carrier; 10 weight ratio (excluding the case of Example 14), loading mechanism of magnesium oxide on the carrier: 01% by weight (
Except for the case of Example 14 < ) ) 70 +z/! Prenol was added onto the catalyst using Lii SV 5. (l
The reaction was carried out at 450° C. by supplying molecular oxygen at a ratio of 0.2 molar to the prenol. The reaction solution was quantified in the same manner as in Example 1, and the reaction results are shown in Table 5.

〔Effect of the invention〕

According to the method of the present invention, senecioaldehyde can be obtained from prenol with high selectivity. As is clear from the above examples, the method of the present invention can produce senecioaldehyde industrially! ! ! This is an excellent method that can be used when building.

Patent applicant Rishi Co., Ltd. Representative Patent Attorney Ken Honda

Claims (1)

[Claims] 1.3-methyl-2-buten-1-ol in gas phase
3, characterized in that it is brought into contact with molecular oxygen at a temperature of 0 to 600°C, and a catalyst comprising three components of silver, copper, and basic metal oxides supported on a carrier having a specific surface area of less than 3 rfl'7f. -Method for producing methyl-2-buten-1-al. 2. The manufacturing method according to claim 1, wherein the ratio of silver and copper supported on the carrier is 99:1 to 50:50 by weight. 3. The amount of basic metal oxide supported is 0.0 with respect to the carrier.
Claim 1 or 29 which has an amount of 1 to 051
4. The manufacturing method described in 4. 4. The manufacturing method according to claims 1 to 3, wherein the carrier is quartz. 5. Claims 1 to 3 in which the carrier is fused alumina
Manufacturing method described in section. 6. The manufacturing method according to claims 1 to 3, wherein the carrier is fused silica.