JPH0471910B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel process for producing alkyloxiranes from aliphatic aldehydes by reaction with sulfur ylides.

The alkyloxirane obtained by the new method is a compound of 1,2-dihydroxyalkane, which is an intermediate for obtaining highly active plant microbicides and plant growth regulators of 2-phenyl-2-triazolylmethyldioxolanes. It is an important intermediate for synthesis. 2-phenyl-2-triazolylmethyldioxolanes and methods of making and using them are disclosed, for example, in U.S. Pat. No. 4,079,062. An important representative compound of this class is 2-(2,4-
dichlorophenyl)-2-(1H-1,2,4-triazol-1-yl-methyl)-4-n-propyldioxolane. This compound is 1,2
- 2-bromomethyl-2-(2,4-dichlorophenyl)-4-n- by reacting pentanediol and ω-bromo-2,4-dichloroacetophenone
Propyl dioxolane was obtained, and this was further added to 1H−1,
Obtained by reacting with 2,4-triazole.

Hydrolysis of the alkyloxirane represented by the formula () obtained by the production method of the present invention is carried out by a conventional method in the presence of an inorganic acid or inorganic base catalyst.

The method of synthesizing oxiranes by adding methyl ylide to the carbonyl group was known earlier in the literature. Dimethyloxosulfonium methyl ylide and dimethylsulfonium methyl ylide were described by Corey and Chaykovsky (J. Amer. Chem.
Soc. 87/6, 1353-1364, 1965 ) as a suitable guide for the synthesis of oxiranes. The synthetic methods disclosed so far are unsuitable for large-scale reactions, either because the yields obtained are insufficient or because the methods are suitable only for aromatic aldehydes or ketones. (West German Patent Publication No.
3315524 and 3315619). Other methods are uneconomical or environmentally unacceptable because they require the use of expensive and/or ecologically harmful reagents (Helv.Chem. Acta Volume 63(6), 1665−
1674, 1980 US Pat. No. 3,442,912 and European Published Patent No. 94,726).

Therefore, there is a need for an inexpensive, large-scale process for producing alkyloxiranes from aliphatic aldehydes. The novel manufacturing method of the present invention includes:
It is surprising that this need is practically met.

The method of the present invention has the following formula (): (wherein R represents an alkyl group having 1 to 12 carbon atoms), the following formula (): (In the formula, R represents an alkyl group having 1 to 12 carbon atoms) and an aliphatic aldehyde represented by the following formula (): (wherein, X represents an alkyl group having 1 to 18 carbon atoms, and Y represents a counter anion) in the presence of an aqueous alkali metal hydroxide solution, The above reaction is carried out by placing the solution of the compound in a reactor and then adding equimolar amounts of aldehyde and sulfonium salt at the same time, and methosulfate anion represented by H ₃ CO-SO ₂ -O as a counter anion. This is a method for producing an alkyloxirane, characterized by selecting the following.

Preferably, the simultaneous addition of aldehyde and sulfonium salt is carried out either from two separate, simultaneously operating metering devices or in the form of one solution containing both aldehyde and sulfonium salt.

Usually the reaction is carried out in two phases, a mixture consisting of an aqueous phase and a water-immiscible organic solvent phase. The primarily organic phase consists of the two reactants and the resulting products. The reaction is advantageously carried out in an inert solvent, but in some cases, especially in continuous operation, it may also be carried out without solvent. The inert solvent used in the present invention is immiscible with water. Suitable for this purpose are aromatic solvents such as benzene, toluene, xylene, nitrobenzene, nitrotoluene, and the various halobenzenes are preferred. Halobenzene derivatives suitable for use as solvents are 2-chlorotoluene, 3-chlorotoluene, 4-chlorotoluene, chlorobenzene, ortho-dichlorobenzene, meta-dichlorobenzene and para-dichlorobenzene, with chlorobenzene being the preferred solvent. For technical reasons, the formulas and the reactants represented by the formulas are preferably used as solutions in organic solvents, while the alkali metal hydroxides are preferably used in the form of concentrated aqueous solutions. It is also advantageous to use formulas and solutions of the formula in which the amount of solvent is present in an amount of 50% or more.

In the oxirane synthesis known from the literature using sulfoxonium salts or in situ formed sulfairides, different counteranions, such as halogen anions, preferably Br
or I, carbonate anion, nitrate anion,
Sulfate, acetate, perchlorate or tosylate anions are used.
It is surprising that the method of the present invention performs best with the methosulfate anion _H3CO -SC2 _- O.

By the use of aqueous solutions of alkali metal hydroxides and pure reactants of the formulas or their solutions in water-immiscible organic solvents,
A two-phase reaction mixture as described above is formed.

A conventional phase transfer catalyst may optionally be added to the two-phase reaction mixture. This process has only a minor effect on the yield of the desired alkyloxirane. Examples of conventional phase transfer catalysts are quaternary ammonium salts such as trimethylbenzylammonium bromide, trimethylbenzylammonium chloride, triethylbenzylammonium chloride, triethylbenzylammonium bromide, tetrabutylammonium chloride or tributylmethylammonium bromide; or 18-crown - Crown ethers such as 6,15-crown 5- or 12-crown-4.

The alkyl radicals in the definitions of R and X consist of all possible isomers having 1 to 18 carbon atoms. However, in the manufacturing method of the present invention,
Straight chain hydrocarbon groups are preferred. R has 2 carbon atoms
to 6 alkyl groups are preferred, and n-propyl groups are most preferred. X is preferably an alkyl group having 5 to 12 carbon atoms, most preferably n-hexyl. The process according to the invention is particularly advantageously used when at the same time R is a C2-C6 alkyl group and X is a C5-C12 alkyl group.

The formula and the reactants represented by the formula are used in approximately equimolar amounts in the production method of the present invention, but
If the excess of the component represented by the formula is within 20 mol%, it will not significantly affect the yield of the compound represented by the formula. The aqueous solution of the alkali metal hydroxide is used in an amount at least equimolar to the sulfonium salt represented by the formula. An excess of alkali metal hydroxide of up to 20 mol of alkali metal hydroxide per molar amount of sulfonium salt is preferred. Most preferably, 1 to 10 moles of alkali metal hydroxide are used for every mole of sulfonium salt. Typically alkali metal hydroxides are sodium hydroxide and potassium hydroxide. In the manufacturing method of the present invention,
Preference is given to using potassium hydroxide. Unreacted alkali metal hydroxide can be reused.

Reaction temperatures usually range from 10°C to 140°C. In order to obtain the highest yield and purity possible,
It is particularly advantageous to carry out the process at a reaction temperature in the range from 60°C to 100°C. If the reaction is carried out in the temperature range mentioned above, the reaction time will range from 10 minutes to 2 hours. The reaction conditions described above are based on a production method under normal pressure. In order to easily carry out this reaction, it is preferred to carry out the process under normal pressure. however, no disturbances have so far been observed when the reaction has been carried out under low or high pressures in the range 10 mbar to 20 bar.

The production method of the present invention can be carried out batchwise or continuously. However, in both cases it must always be ensured that the formula and the reactant represented by the formula are added simultaneously to the alkali metal hydroxide solution.

In a preferred embodiment of the method of the invention, 60°C
The reaction is carried out in a mixture of chlorobenzene and water in the temperature range from 100°C to 100°C.

The advantage of the new production method is that 60
This is most evident when reacting dimethylhexylsulfonium methosulfate with butyraldehyde in the temperature range from 100°C to 100°C.

The novel process of the invention for the production of alkyloxiranes is illustrated by the following examples.

Example 1 2-Propyloxirane A glass reactor with a stirrer is filled with 800 g (10 mol) of a 50% aqueous solution of sodium hydroxide at a temperature of 80°C.

With effective stirring, 516 g (2 moles) of dimethylhexylsulfonium methosulfate and 158.4 g of butyraldehyde in 516 g of chlorobenzene.
(2.2 mol) solution is added dropwise. Add while keeping the temperature at 80℃. After 15 minutes, the reaction mixture is cooled and diluted with 2 portions of water. The organic phase is separated, dried over magnesium sulfate and fractionated through a packed column to determine the purity.
136 g of 95% 2-propyloxirane (yield 75% of theory) are obtained. Boiling point: 88℃ to 92℃
℃.

Example 2 2-Propyloxirane A cascade of stirred reactors with a total volume of 0.5 was filled with the reaction mixture obtained in Example 1 and the temperature was brought to 80 °C.
℃. Then, 800 g (10 moles) of a 50% aqueous solution of sodium hydroxide, 516 g (2 moles) of dimethylhexylsulfonium methosulfate, 151.2 g (2.1 moles) of butyraldehyde and chlorobenzene were added.
Add 516 g of the mixture uniformly over 2 hours in the same molar ratio. The average residence time in the cascade of stirred reactors is 30 minutes. Dilute the overflowing reaction solution with water. The organic phase was separated, dried over magnesium sulfate and fractionated through a packed column, yielding 145 g of 2-propyloxirane with a purity of 95% (yield of theoretical value).
80%) is obtained. Boiling point: 88℃ to 92℃.

Example 3 2-Propyloxirane 50% cascade of stirred reactors with a total volume of 0.5
Fill with 280 g (2.5 moles) of potassium hydroxide solution,
Bring to 80℃. With effective stirring, a mixture of 129 g (0.5 mol) dimethylhexylsulfonium methosulfate, 37.8 g (0.525 mol) butyraldehyde and 129 g chlorobenzene is added dropwise over 30 minutes to bring the total amount to 0.5. Then an additional 1120 g (10 moles) of potassium hydroxide and 516 g of dimethylhexylsulfonium methosulfate
(2 moles), butyraldehyde 151.2g (21 moles)
and 516 g of chlorobenzene were added at a constant molar ratio over 2 hours. When the overflowing reaction solution is treated as described in Examples 1 and 2, the boiling point is 88
95% 2-propyloxirane with temperature between ℃ and 92℃
Obtain 145g (80% of theoretical value).

Example 4 2-Propyloxirane A glass reactor equipped with a stirrer is filled with 800 g (10 mol) of a 50% aqueous solution of sodium hydroxide at a temperature of 80°C. With effective stirring, add 516 g (2 moles) of dimethylhexylsulfonium methosulfate.
A stirred mixture of 158.4 g (22 mol) of butyraldehyde and butyraldehyde in 516 g of xylene is added dropwise. The temperature continues to be maintained at 80°C during this addition. After 15 minutes, the reaction mixture is cooled and diluted with 2 portions of water. The organic phase is separated, dried over magnesium sulphate and fractionated through a packed column, giving 127 g of 2-propyloxirane with a purity of 95% (yield 70% of theory). Boiling point is 88℃ to 92℃.

Example 5 2-Propyloxirane A cascade of stirred reactors with a total volume of 0.5 as in Example 3 was charged with 50% aqueous potassium hydroxide solution,
dimethylhexysulfonium methosulfate,
Fill with butyraldehyde and chlorobenzene.
Thereafter, the pure components of potassium hydroxide, dimethylhexisulfonium methosulfate and butyraldehyde were poured out 5:1, respectively, until no chlorobenzene was detected in the reaction mixture.
Add at the same time 1.05 mol. After that, 1120 g (10 moles) of a 50% aqueous solution of potassium hydroxide and 516 g of dimethylhexylsulfonium methosulfate were added.
(2 mol) and 151.2 g (2.1 mol) of butyraldehyde are added simultaneously within 1.5 hours. When the overflowing reaction mixture was treated as in Example 2, 95%
127g of 2-propyloxirane (70% of theory)
get.

Claims (1)

[Claims] Primary formula (): (In the formula, R represents an alkyl group having 1 to 12 carbon atoms) In producing an alkyloxirane represented by the following formula (): (In the formula, R represents an alkyl group having 1 to 12 carbon atoms) and an aliphatic aldehyde represented by the following formula (): (wherein, X represents an alkyl group having 1 to 18 carbon atoms, and Y represents a counter anion) in the presence of an aqueous alkali metal hydroxide solution, The above reaction is carried out by placing the solution of the compound in a reactor and then adding equimolar amounts of aldehyde and sulfonium salt at the same time, and methosulfate anion represented by H ₃ CO-SO ₂ -O as a counter anion. A method for producing an alkyloxirane, the method comprising selecting an alkyloxirane. 2. The production method according to claim 1, wherein the reaction is carried out in an inert organic aromatic solvent. 3. The production method according to claim 2, wherein the reaction is carried out in a mixed solution of halobenzene and water. 4. The production method according to claim 3, wherein the reaction is carried out in a mixed solution of chlorobenzene and water. 5. The manufacturing method according to claim 1, wherein the reaction temperature is in the range of 60°C to 100°C. 6. The manufacturing method according to claim 1, wherein R in the above formula is an alkyl group having 2 to 6 carbon atoms. 7. The manufacturing method according to claim 6, wherein R in the above formula is a propyl group. 8. The manufacturing method according to claim 1, wherein in the above formula, X is an alkyl group having 5 to 12 carbon atoms. 9. The manufacturing method according to claim 8, wherein in the above formula, X is a hexyl group. 10. The manufacturing method according to claim 1, wherein in the above formula, R is an alkyl group having 2 to 6 carbon atoms, and X is an alkyl group having 5 to 12 carbon atoms. 11. The manufacturing method according to claim 1, characterized in that the reaction is carried out in a mixture of chlorobenzene and water at a temperature range of 60°C to 100°C. 12 Butyraldehyde in a temperature range of 60℃ to
2. The method according to claim 1, wherein the reaction is carried out with dimethylhexylsulfonium methosulfate in a mixture of chlorobenzene and water at 100° C. in the presence of potassium hydroxide.