JP3523360B2 - Method for producing unsaturated alcohol - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a γ, δ-unsaturated alcohol. γ, δ-unsaturated alcohols can be intermediates for many industrially important compounds. In particular, 3-methyl-3-buten-1-ol is a precursor of isoprene used as a raw material for synthetic rubber. As
Further, it is a compound useful as an intermediate for medicines and fragrances. [0002] The reaction of producing an unsaturated alcohol by reacting an olefin with formaldehyde is known as an ene reaction, and has long been known to proceed in the presence of a Lewis acid catalyst or by heating. ing. As a method using a Lewis acid catalyst, an olefin is reacted with gaseous formaldehyde, paraformaldehyde, trioxane, etc. in the presence of a catalyst selected from stannic chloride, zinc chloride, silicon tetrachloride, and zinc dichloroacetate under anhydrous conditions. To produce primary unsaturated alcohols (US Patent No.
2,308,192), a method of reacting an olefin with a trioxane in the presence of stannic chloride [Journal of the American Chemical Society (J.
Am. Chem. Soc.), 81, 133, 1959;
Reaction of olefins with paraformaldehyde in the presence of alkyl aluminum chloride [Journal of the American Chemical Society (J. Am. C.)
Hem. Soc.), vol. 104, p. 555, 1982], a method of reacting an olefin with paraformaldehyde in the presence of a boron trifluoride etherate complex in an acetic anhydride / methylene chloride solvent [Helvetica Kimika. Actor (Helvetic
a Chimica Acta), 64, 158, 1981]. In addition, gaseous formaldehyde generated from paraformaldehyde is used in the reaction in the presence of water, and an olefin is used in the presence of zinc chloride, stannic chloride or silicon tetrachloride of 10 mol% or less based on formaldehyde. A method for producing a primary unsaturated alcohol by reaction (see GB 1,205,762) is known. In a reaction using a Lewis acid catalyst under the above-mentioned anhydrous conditions, the Lewis acid itself is susceptible to hydrolysis in the presence of water. Formaldehyde, trioxane, etc. had to be used. These are more expensive than aqueous formaldehyde solutions and are not suitable as inexpensive raw materials for producing unsaturated alcohols. Also, UK Patent No. 1,20
The method described in US Pat. No. 5,762 has the advantage that the reaction proceeds even in the presence of water, but it requires the use of formaldehyde generated from paraformaldehyde containing 30% or less of water, and is easily available and inexpensive. However, there is a problem that a 30 to 60% aqueous formaldehyde solution cannot be used as it is. Furthermore, in the conventional methods using these Lewis acids, the selectivity of unsaturated alcohols based on formaldehyde is generally 40% or less, which is not satisfactory industrially. [0004] The present inventors have means for solving the problems] is an inexpensive aqueous formaldehyde solution, and mild result of intensive studies on a method for producing an unsaturated alcohol under the conditions of the general formula (I) embedded 3] (Wherein R ¹ , R ² and R ³ each have 1 to 10 carbon atoms which may be substituted with a hydrogen atom or a hydroxyl group)
Represents an alkyl group, an alkenyl group or an aryl group. ) Is reacted with an aqueous formaldehyde solution to give a compound of the general formula (II) (Wherein R ¹ , R ² and R ³ are as defined above), tin, a solvent for uniformly dissolving the olefin and an aqueous formaldehyde solution. The present invention has been completed by finding a method for producing an unsaturated alcohol , wherein the reaction is carried out at a low temperature in the presence of a halide of at least one metal selected from the group consisting of gallium, indium and scandium. . According to the present invention, an inexpensive aqueous formaldehyde solution is used as a raw material for formaldehyde by reacting in the presence of a specific catalyst in a solvent capable of uniformly dissolving the olefin of the general formula (I) and an aqueous formaldehyde solution. Can be used to produce the desired unsaturated alcohol under mild conditions. The olefin used in the present invention has the general formula (I): (Wherein R ¹ , R ² and R ³ are as defined above). Examples of specific olefins, R ^1, R ² and R ³ are each a hydrogen atom, an alkyl group or an aryl group propylene, isobutene, 2-methyl-1-butene, 2-
Methyl-1-pentene, 2-methyl-1-hexene, 2
-Methyl-1-heptene, 2-methyl-1-octene,
2,3-dimethyl-1-butene, α-methylstyrene,
α-ethylstyrene, methylenecyclohexane, camphene, methylenenorbornane and the like in which R ³ and the alkyl group of R ¹ or R ² are included in a part of the same cyclic structure. Examples of the substitution with a hydroxyl group include 3-methyl-3-buten-1-ol and 7-octen-1-ol. As the olefin, not only a single compound but also a mixture with another olefin can be used. For example, when using isobutene,
Spent BB containing butenes can also be used. The amount of the olefin to be used is preferably 0.5 to 50 mol times, more preferably 1 to 20 mol times, relative to formaldehyde. When the amount of olefin used is small, the selectivity of the target unsaturated alcohol decreases, and when the amount used increases, the reaction rate decreases and the utility required for olefin recovery increases,
The industrial value decreases. The aqueous formaldehyde solution used in the present invention may be a 10-70% aqueous solution. 1
If it is 0% or less, the selectivity of the target unsaturated alcohol is reduced, and if it is 70% or more, precipitation of paraformaldehyde becomes remarkable, and handling as an aqueous formaldehyde solution becomes substantially impossible. As the aqueous formaldehyde solution, anhydrous formaldehyde, paraformaldehyde or an aqueous formaldehyde solution obtained as a mixture of trioxane and water can also be used. As the solvent used in the present invention, any solvent can be used as long as it is a solvent in which the olefin represented by the general formula (I) and the aqueous solution of formaldehyde are uniformly dissolved and the solvent is inert to the reaction. is there. Examples of the solvent include nitriles such as acetonitrile, fumaronitrile, and malononitrile; alcohols such as isopropyl alcohol, isobutyl alcohol, and t-butyl alcohol; ethers such as tetrahydrofuran and 1,4-dioxane; It is not limited. When using a tin halide as a catalyst, it is particularly preferred to use acetonitrile or t-butyl alcohol. The amount of the solvent to be used is appropriately determined depending on the types of the olefin and the solvent, but it is generally preferable to add the water in the formaldehyde aqueous solution as a raw material so that the water concentration is 10% by weight or less of the whole reaction solution. The metal halide used as a catalyst in the present invention is a halide of at least one metal selected from the group consisting of tin, gallium, indium and scandium. Specific examples of metal halides include stannic (IV) chloride, stannic (IV) bromide, stannic (IV) iodide, gallium (III) chloride, gallium (III) bromide, indium chloride ( III), indium (III) bromide, scandium (III) chloride, scandium (III) bromide and hydrates thereof. Further, a mixture of these may be used as the metal halide, and another metal halide such as lithium chloride, hydrogen halide, or the like may be added to the reaction system in order to reduce the amount of the catalyst used. The amount of the metal halide used is in the range of 0.001 mol to 1 mol per 1 mol of formaldehyde. [0011] The reaction temperature is preferably in the range of 0 to 150 ° C, particularly preferably in the range of 20 to 100 ° C. At 0 ° C. or lower, the reaction rate is low and the reaction takes a long time. At 150 ° C. or higher, the decomposition reaction of formaldehyde and the generated unsaturated alcohol is accelerated, and the yield of the target unsaturated alcohol is reduced. The reaction time is appropriately determined depending on the difference in the reaction rate, but under the above reaction conditions, 10 minutes to 4 minutes.
The reaction is completed within a time period in the range of 8 hours. The reaction can be carried out by any method such as a batch system or a continuous system. Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. EXAMPLE 1 23.0 g (0.56 mol) of acetonitrile, 4.2 g (70 mmol) of a 50% aqueous formaldehyde solution, 1.82 g (7.0 mmol) of anhydrous stannic chloride and 39.000 g of isobutene were placed in a 100 ml electromagnetically stirred autoclave.
2 g (0.70 mol) was added and stirred at 60 ° C. for 2 hours. After completion of the reaction, the autoclave was cooled, and then unreacted isobutene was released. As a result of analyzing 33.9 g of the recovered reaction solution, all of the formaldehyde had disappeared.
4.18 g of 3-methyl-3-buten-1-ol (4
8.5 mmol) and 0.10 g (0.88 mmol) of 4,4-dimethyl-1,3-dioxane.
The conversion of formaldehyde was 100%, the selectivity of unsaturated alcohol on the basis of formaldehyde was 69.3%, and the selectivity of alkyl methadioxane was 2.5%. Example 2 34.4 g (0.84 mol) of acetonitrile, 4.2 g (70 mmol) of a 50% aqueous solution of formaldehyde, 365 mg (1.4 mmol) of anhydrous stannic chloride and 39.000 of isobutene were placed in a 100 ml electromagnetically stirred autoclave.
2 g (0.70 mol) was added and stirred at 80 ° C. for 1 hour. After completion of the reaction, the autoclave was cooled, and then unreacted isobutene was released. Formaldehyde was 0.90 g (29.9 mmol) in 32.3 g of the collected reaction solution.
Remaining, 2.44 g (28.3 mmol) of 3-methyl-3-buten-1-ol, 4,4-dimethyl-
0.03 g (0.24 mmol) of 1,3-dioxane
Had been generated. The conversion of formaldehyde is 57.3.
%, The selectivity of unsaturated alcohol based on formaldehyde is 70.6%, and the selectivity of alkylmetadioxane is 1.60%.
2%. Example 3 23.0 g (0.56 mol) of acetonitrile, 4.2 g (70 mmol) of a 50% aqueous formaldehyde solution, 365 mg (1.4 mmol) of anhydrous stannic chloride, 298 m of lithium chloride were placed in a 100 ml electromagnetically stirred autoclave.
g (7.0 mmol) and 39.2 g of isobutene
(0.70 mol) and stirred at 80 ° C. for 2 hours. The same post-treatment as in Example 1 was performed, and the reaction solution was analyzed. The conversion of formaldehyde was 81.8%, the selectivity of unsaturated alcohol based on formaldehyde was 65.3%, and the selectivity of alkyl methadioxane was 3.0%. Examples 4 and 5 The reaction was carried out under the same conditions as in Example 1 except that the reaction solvent was changed to t-butanol or 1,4-dioxane, and the amounts shown in Table 1 were used. Table 1 shows the results. Examples 6 to 9 Reactions were carried out under the same conditions as in Example 1 except that the type of catalyst was changed to stannic bromide, scandium chloride, gallium chloride or indium chloride, respectively. Table 1 shows the results. Examples 10 and 11 2-methyl-1 as olefin instead of isobutene
The reaction was carried out under the same conditions as in Example 1 except that -pentene or 3-methyl-3-buten-1-ol was used.
Table 1 shows the results. Examples 12 and 13 The reaction was carried out under the same conditions as in Example 1 except that an aqueous formaldehyde solution having the concentration shown in Table 1 was used. Table 1 shows the results. Comparative Example 1 The reaction was carried out under the same conditions as in Example 1 except that the reaction solvent was changed to chloroform and the amounts shown in Table 1 were used. Table 1 shows the results. Comparative Examples 2 to 4 The reaction was carried out under the same conditions as in Example 1 except that ferric chloride, aluminum chloride or titanium tetrachloride was used as a catalyst. Table 1 shows the results. When these catalysts are used, the selectivity of the unsaturated alcohol is low or a large amount of alkylmetadioxane is produced, which is not preferable as an industrial production method of the unsaturated alcohol. [Table 1] According to the present invention, an inexpensive aqueous formaldehyde solution is used by reacting an olefin and an aqueous formaldehyde solution in the presence of a specific catalyst in a solvent capable of uniformly dissolving the olefin and an aqueous formaldehyde solution, and Unsaturated alcohols can be produced under mild conditions.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C07C 33/18 C07C 33/18 // C07B 61/00 300 C07B 61/00 300 (58) Investigation field (Int.Cl. ⁷ , DB name) C07C 29/38 C07C 33/025 C07C 33/035 C07C 33/18 C07C 33/20 C07C 33/42 C07C 41/26 C07C 43/178 B01J 27/125 B01J 27/135 C07B 61/00 300

Claims (1)

(57) [Claim 1] The general formula (I) (Wherein R ¹ , R ² and R ³ each have 1 to 10 carbon atoms which may be substituted with a hydrogen atom or a hydroxyl group)
Represents an alkyl group, an alkenyl group or an aryl group. ) Is reacted with an aqueous formaldehyde solution to give a compound of the general formula (II) (Wherein R ¹ , R ² and R ³ are as defined above), tin, a solvent for uniformly dissolving the olefin and an aqueous formaldehyde solution. A method for producing an unsaturated alcohol, wherein the reaction is carried out at a temperature of 20 to 100 ° C. in the presence of a halide of at least one metal selected from the group consisting of gallium, indium and scandium.