Process for preparing alkali metal alkoxides

Abstract

The invention relates to a method for producing an alkali metal alkoxide, comprising the following steps: i) providing an organic compound having at least one-OH group and having a molecular weight of 75 g / mol to 750 g / mol in a reaction vessel in an inert atmosphere; ii) adding a C1-6 alkali metal alcoholate to obtain a reaction mixture; iii) heating the reaction mixture of step ii) to 25 DEG C to 180 DEG C under stirring to obtain an alkali metal alkoxide and a C1-6 alcohol; and iv) distilling off the C1-6 alcohol obtained; wherein during distillation, at least one non-polar solvent is added continuously or in batches to the mixture, said non-polar solvent having a higher boiling point than the obtained alcohol.

Description

[0001] The present invention relates to a method for preparing an alkali metal alkoxide, which comprises the following steps:

[0002] i) providing an organic compound having at least one -OH group and a molecular weight of 75 g / mol to 750 g / mol in a reaction vessel in an inert atmosphere;

[0003] ii) Join C 1-6 an alkali metal alcoholate to obtain a reaction mixture;

[0004] iii) heating the reaction mixture of step ii) to 25°C to 180°C under stirring to obtain an alkali metal alkoxide and C 1-6 alcohol; and

[0005] iv) distilling off the obtained C 1-6 Alcohol; wherein during the distillation, at least one non-polar solvent is continuously or batchwise added to the mixture, the non-polar solvent having a boiling point higher than the alcohol obtained.

[0006] Alkali metal alkoxides are used for various purposes, such as aldol addition, esterification / transesterification, malonate synthesis, ether formation and other general uses as bases. Alkali metal alkoxides are also widely used in the food industry, for example in margarine production or vitamin A synthesis; in pharmaceutical chemistry, for example in the production of antibiotics, analgesics, chemotherapeutics and epilepsy drugs; in agricultural chemistry, for example in the production of herbicides and fungicides; and in many other application areas, for example in the production of fluorescent whitening agents, UV absorbers and photoinitiators.

[0007] Various processes are known in the prior art for preparing alkali metal alkoxides.

[0008] A known method involves the reaction of an alcohol with an alkali metal. During this reaction, hydrogen is produced, wherein the release of hydrogen can be increased rapidly when low molecular weight alcohols are used ( Online.Georg Thieme Verlag, retrieved on May 28, 2020).

[0009] Another alternative method includes the reaction of alcohols with strong bases such as alkali amides or alkali hydrides. In this reaction, ammonia or hydrogen is produced as a by-product. Since alkali amides are very sensitive, the product yields fluctuate strongly.

[0010] Another alternative method described in EP 1195369 A1 comprises the reaction of an alcohol with an alkali metal amalgam. After the reaction, the final product is contaminated with hydrogen and mercury. A further development of the method disclosed in EP 0776995 A1 comprises the reaction of the corresponding alcohol with another alcoholate in the liquid phase in the presence of an electric field. Metal ions are introduced under the influence of the electric field to obtain the desired alcoholate, preferably in different regions separated by ion exchange membranes, the other alcoholate is decomposed and the metal is then introduced into the alcohol.

[0011] Another alternative process described in US 3,418,383 discloses the preparation of alkali metal alcoholates by a modified exchange reaction between a lower alcoholate of an alkali metal and a higher alcohol to prepare a higher alcoholate of an alkali metal, wherein the exchange reaction is carried out with the vapor of the higher alcohol passing through the exchange reaction mass. The reaction time of this reaction is very long and a high molar amount of alcohol is required for the reaction.

[0012] However, all known methods yield alkali metal alkoxides containing impurities, which may result in reduced storage stability of the obtained alkali metal alkoxides, thus requiring labor-intensive purification processes, or being unsuitable as starting materials for pharmaceutical applications.

[0013] It was therefore an object of the present invention to provide an improved process for producing alkali metal oxides which have low impurities and which do not require a separate additional purification process.

[0014] This is achieved by the method according to the invention, which implements a method comprising C 1-6 Complete conversion of the starting compound of the alkali metal alkoxide, thereby achieving high purity of the resulting alkali metal alkoxide, without the need for complex separations in the processes known in the art.

[0015] In particular, the object is achieved by a process for preparing an alkali metal alkoxide, comprising the following steps:

[0016] i) providing an organic compound having at least one -OH group and a molecular weight of 75 g / mol to 750 g / mol in a reaction vessel in an inert atmosphere;

[0017] ii) Join C 1-6 an alkali metal alcoholate to obtain a reaction mixture;

[0018] iii) heating the reaction mixture of step ii) to 25°C to 180°C under stirring to obtain an alkali metal alkoxide and C 1-6 alcohol; and

[0019] iv) distilling off the obtained C 1-6Alcohol; wherein during the distillation, at least one non-polar solvent is continuously or batchwise added to the mixture, the non-polar solvent having a boiling point higher than the alcohol obtained.

[0020] In order to achieve complete conversion, it is required that at least one nonpolar solvent having a higher boiling point than the alcohol obtained is added continuously or portionwise to the mixture during distillation. The alkali metal alkoxide obtained has a high purity and is isolated as a liquid without further purification or as a crystalline powder with good flow properties, which is easy to filter.

[0021] The distillation may be any conventional distillation method known in the art, which is preferably azeotropic distillation, reactive distillation, vacuum distillation or fractional distillation or a combination of at least two of the foregoing techniques.

[0022] When performing the distillation, an inert gas flow, preferably a nitrogen flow, may be applied, preferably at a flow rate of 10 NL / h to 300 NL / h, more preferably 50 NL / h to 200 NL / h.

[0023] "At least one" means one or more, i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9 or more. "At least one" in relation to any component herein refers to the number of chemically different molecules, i.e., the number of different types of the substance being referred to, rather than the total number of molecules. For example, "at least one non-polar solvent" means that at least one type of molecule falling within the definition of a non-polar solvent is used, but there may also be two or more different types of non-polar solvents falling within this definition, but it does not mean that there are only one or more non-polar solvent molecules of one type.

[0024] In particular, the present invention relates to:

[0025] 1. A method for preparing an alkali metal alkoxide, more preferably a potassium alkoxide, comprising or consisting of the following steps:

[0026] i) providing an organic compound having at least one -OH group and a molecular weight of 75 g / mol to 750 g / mol, preferably 75 g / mol to 350 g / mol, in a reaction vessel in an inert atmosphere;

[0027] ii) Join C 1-6 Alkali metal alcoholate, more preferably C 1-4 Alkali metal alcoholate, more preferably C 1-4 Potassium alcoholate to obtain a reaction mixture;

[0028] iii) heating the reaction mixture of step ii) to 25°C to 180°C, preferably 60°C to 170°C, under stirring to obtain an alkali metal alkoxide and C 1-6 Alcohol, preferably C 1-4 alcohol; and

[0029] iv) distilling off the obtained C 1-6 Alcohol, preferably C 1-4 alcohol; wherein during the distillation, at least one non-polar solvent is added continuously or batchwise to the mixture, the non-polar solvent having a boiling point higher than the alcohol obtained, preferably at least 138°C, more preferably 138°C to 300°C, preferably in up to four batches.

[0030] If step iii) is carried out at a temperature of 170° C. or lower, the purity of the obtained alkali metal alkoxide is further increased.

[0031] 2. The method according to item 1, wherein the organic compound having at least one -OH group is selected from substituted or unsubstituted aliphatic or aromatic hydrocarbons, silyl ethers, polyols, ethers and polyethers or mixtures thereof, preferably, the organic compound is selected from phenol, benzyl alcohol, 2-alkoxyethanol, 2-aryloxyethanol, 2-siloxyethanol, 2-(2-alkoxyethoxy)ethanol, 2-(2-aryloxyethoxy)ethanol, 2-(2-siloxyethoxy)ethanol, 3-alkoxypropanol, 3-aryloxypropanol, 3-siloxypropanol, 2-(2-alkoxyethoxy)ethanol, 2-(2-aryloxyethoxy)ethanol, 2 -(2-silanyloxyethoxy)ethanol, diols, triols, tetraols, more preferably, the compound is selected from 2-benzyloxyethanol, 2-methoxyethanol, diethylene glycol monobenzyl ether, 2-tert-butoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(tert-butyl-dimethylsilanyloxy)ethanol, 2-(tert-butyldiphenylsilanyloxy)ethanol, 2-(2-(tert-butyldimethylsilylethoxy)ethanol, 2-(2-tert-butyldiphenylsilylethoxy)ethanol, pentaerythritol, triethylene glycol, tetraethylene glycol, 2,2'-((2-((2-hydroxyethoxy)methyl)-2-(hydroxymethyl)propane-1,3-diyl)bis(oxygen Preferably, the organic compound having at least one -OH group is selected from phenol, benzyl alcohol, 2-alkoxyethanol, 2-aryloxyethanol, 2-siloxyethanol, 2-(2-alkoxyethoxy)ethanol, 2-(2-aryloxyethoxy)ethanol, 2-(2-siloxyethoxy)ethanol, 3-alkoxypropanol, 3-aryloxypropanol, 3-siloxypropanol, 2-(2-alkoxyethoxy)ethanol, 2-(2-aryloxyethoxy)ethanol, 2-(2-siloxyethoxy)ethanol, diol, triol, tetraol. More preferably, the organic compound having at least one -OH group is selected from phenol, benzyl alcohol, 2-alkoxyethanol, 2-aryloxyethanol, 2-siloxyethanol, 2-(2-alkoxyethoxy)ethanol, 2-(2-aryloxyethoxy)ethanol, 2-(2-siloxyethoxy)ethanol, diol, triol, tetraol. The organic compound having one less -OH group is selected from 2-benzyloxyethanol, 2-methoxyethanol, diethylene glycol monobenzyl ether, 2-tert-butoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(tert-butyl-dimethylsilyloxy)ethanol, 2-(tert-butyldiphenylsilyloxy)ethanol, 2-(2-(tert-butyldimethylsilylethoxy)ethanol, 2-(2-tert-butyldiphenylsilylethoxy)ethanol, pentaerythritol, triethylene glycol, tetraethylene glycol, 2,2'-((2-((2-hydroxyethoxy)methyl)-2-(hydroxymethyl)propane-1,3-diyl)bis(oxy))bis(ethane-1-ol), and 3-methoxypropanol.

[0032] 3. The method according to any one of the preceding items, wherein the C 1-6 The alkali metal alcoholate is selected from potassium methoxide, potassium ethoxide, potassium 2-methylpropan-2-olate, potassium propan-2-olate, potassium propan-1-olate, potassium butan-2-olate and potassium tert-butoxide.

[0033] 4. The method according to any one of the preceding items, wherein the at least one non-polar solvent is selected from toluene, dodecane, tetradecane, xylene or tetraglyme or a mixture thereof. Preferably, the at least one solvent is selected from toluene, xylene, cumene, biphenyl, octane, nonane, C 10-20 Alkanes and their isomeric forms, C 10-20 Decane and its isomeric forms, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether or mixtures thereof.

[0034] 5. The method according to any of the preceding items, wherein the reactor comprises a rotating element for stirring; preferably

[0035] The at least one non-polar solvent is added when the torque M of the rotating element increases by at least 1.5 times, and the torque M decreases by at least 1.5 times after the at least one non-polar solvent is added.

[0036] 6. A method according to any of the preceding items, wherein the at least one non-polar solvent is present in an amount of 1 ml / mmol to 20 ml / mmol, preferably 1 ml / mmol to 10 ml / mmol, relative to the organic compound having at least one -OH group and a molecular weight of 75 g / mol to 750 g / mol, preferably 75 g / mol to 350 g / mol.

[0037] 7. The process according to any of the preceding items, wherein the reaction time is at least 3 hours, preferably at least 24 hours, for batchwise addition or at least 0.5 hours, preferably 6 hours, for continuous addition.

[0038] 8. A method according to any one of the preceding items, wherein after the reaction, the at least one non-polar solvent is washed out with a volatile non-polar solvent, preferably, the volatile non-polar solvent is selected from methyl tert-butyl ether and n-pentane.

[0039] 9. The method according to any one of the preceding items, wherein the organic compound having at least one -OH group and a molecular weight of 75 g / mol to 750 g / mol, preferably 75 g / mol to 350 g / mol, is 1-6 Alkali metal alcoholates, C 1-4 The alkali metal alcoholate is present in a molar ratio of 2:1 to 1:1.

[0040] In one embodiment of the invention, the reaction vessel comprises a rotating element, and

[0041] - when the torque M of the rotating element increases by at least 1.5 times, adding the at least one non-polar solvent, and

[0042] After the addition of the at least one non-polar solvent, the moment M decreases by at least a factor of 1.5.

[0043] In one embodiment of the present invention, the at least one non-polar solvent is present in an amount of 1 ml / mmol to 20 ml / mmol, preferably 1 ml / mmol to 10 ml / mmol.

[0044] In another embodiment, the at least one solvent is non-polar and aprotic, preferably selected from aromatic hydrocarbons, aliphatic hydrocarbons, ether solvents or mixtures thereof.

[0045] In a preferred embodiment, the at least one non-polar solvent is a hydrocarbon having at least 4 carbon atoms, preferably selected from toluene, dodecane, tetradecane, xylene, tetraglyme or a silane or a siloxane.

[0046] In another preferred embodiment, the reaction time is at least 12 hours, preferably at least 24 hours. In a preferred embodiment, step iv) is performed for 4 to 5 hours.

[0047] In another embodiment, after the reaction time, the reaction is cooled to room temperature at a cooling ramp of about 1 K / min.

[0048] In another preferred embodiment, the at least one non-polar solvent is washed out with a volatile non-polar solvent after the reaction. The volatile non-polar solvent is preferably an aprotic solvent, more preferably selected from MTBE, toluene, pentane or hexane.

[0049] In another embodiment, the resulting alkali metal alkoxide is dried under an inert atmosphere and under applied vacuum at room temperature for not less than 5 hours.

[0050] The alkali metal alkoxide content (assay) obtained may be at least 90%, preferably at least 95%, more preferably at least 99%, as determined by titration. Example

[0051] By an organic compound having at least one -OH group and C 1-6 Alkali metal alkoxides are prepared by reacting alkali metal alkoxides.

[0052] General approach:

[0053] Before the reaction, the reaction equipment was inertized with an inert gas and kept dry. An organic compound having at least one -OH group (1 equivalent) was charged into the reactor, and at least one C 1-6 It is necessary to handle the alkali metal alcoholate, such as methanolate (1 equivalent), under an inert atmosphere. At the start of the reaction, the flask is heated and an inert gas is introduced into the material. The gas flow is maintained throughout the reaction.

[0054] Then, the obtained C 1-6 The alcohol was converted to complete (IPC).

[0055] IPC: C 1-6 NMR of alcohols.

[0056] Stirring becomes difficult during the distillation because the viscosity becomes very high (indicated by the increase in stirrer torque). The viscosity is reduced by adding at least one non-polar solvent continuously or in portions. After the distillation step, a slurry containing the alkali metal alkoxide is obtained.

[0057] The cooling rate (for laboratory tests) was kept at -0.1 K / min to 1 K / min, down to room temperature. The cooling program must be adapted to the equipment under consideration and a person skilled in the art is able to do this within the scope of his general knowledge.

[0058] For washing, the slurry was pressure loaded onto a filter and the filter cake was washed twice with a non-polar solvent. The final product was dried under vacuum with an inert gas.

[0059] In the presence of n-dodecane, benzyloxyethanol reacts to form potassium benzyloxyethanol

[0060]

[0061] Before carrying out the reaction, the required reaction equipment is inerted with inert gas and kept dry. Under an inert atmosphere (dry atmosphere), 627.7 g of benzyloxyethanol (99%; 4 mol; 1 equivalent) are charged into the reactor and 166.8 g of potassium methoxide (98.95; 4 mol; 1 equivalent) are added. After the addition of the starting materials, the reactor is (again) inerted. The reaction is heated to 110° C. with continuous stirring and nitrogen is introduced into the material. A 3-blade propeller stirring shaft with a total blade diameter of 75 mm is used. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. After a reaction time of about 160 h, the methanol is distilled off.

[0062] Complete conversion was checked by NMR using residual methanol content.

[0063] During the distillation, stirring (rpm 100) becomes difficult because the viscosity becomes very high. The torque increases from 0-4 Ncm to 15-30 Ncm. The viscosity can be reduced by adding n-dodecane (0.1-0.2 L), obtaining a homogeneous reaction mixture, by which the torque is reduced to 2-6 Ncm. During the reaction, n-dodecane is carried out as an aerosol at the top of the reactor and must be replenished in several portions. The total amount of n-dodecane is (100%; 0.25 L; 1.1 mol).

[0064] At the end of the distillation, 250 mL (anhydrous / 100%) toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form.

[0065] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0066] For washing, the slurry is pressurized onto the filter. The residue is transferred to the cake with 200 mL of toluene (anhydrous), and the filter cake is washed twice with 125 mL of toluene (anhydrous) each time. Afterwards, the filter cake is washed twice with 200 mL of dry MTBE each time. The final product is dried at RT by applying an inert gas and vacuum. Yield: 91.3% Titration purity: 98.9% by weight.

[0067] In the presence of n-tetradecane, benzyloxyethanol reacts to form potassium benzyloxyethanol

[0068]

[0069] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 310.6 g of benzyloxyethanol (99%; 2 mol; 1 equivalent) are charged into the reactor and 144.6 g of potassium methoxide (98.95%; 2 mol; 1 equivalent) are added. After the addition of the raw materials, the reactor is (re) inerted. The reaction is heated to 120° C. with continuous stirring and nitrogen is started to be introduced into the material. A 3-blade propeller stirring shaft with a total blade diameter of 75 mm is used. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. After a reaction time of about 168 h, the methanol is distilled off.

[0070] Complete conversion was checked by NMR using residual methanol content.

[0071] During the distillation, stirring (rpm 100) becomes difficult because the viscosity becomes very high. The torque increases from 0-5 Ncm to 10-18 Ncm. The viscosity can be reduced to obtain a homogeneous reaction mixture by adding n-tetradecane (0.1-0.2 L), by which the torque is reduced to 2-4 Ncm. During the reaction, n-tetradecane is taken out as an aerosol at the top of the reactor and has to be replenished in several portions. The total amount of n-tetradecane (100%; 0.45 L; 1.7 mol)

[0072] At the end of the distillation, 50 mL (anhydrous / 100%) toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form.

[0073] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0074] For washing, the slurry is pressurized onto the filter. The residue is transferred to the cake with 25 mL of toluene (anhydrous), and the filter cake is washed three times with 25 mL of toluene (anhydrous) each time. Afterwards, the filter cake is washed twice with 200 mL of dry MTBE each time. The final product is dried by applying an inert gas and vacuum at RT. Yield: 92.4% Titration purity: 98.5 wt %.

[0075] In the presence of o-xylene, benzyloxyethanol reacts to form potassium benzyloxyethanol

[0076]

[0077] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 415.6 g of benzyloxyethanol (99%; 2.7 mol; 1 equivalent) are charged to the reactor and 193.4 g of potassium methoxide (98.95%; 2.7 mol; 1 equivalent) are added. After the addition of the raw materials, the reactor is (re) inerted. The reaction is heated to 120° C. with continuous stirring and nitrogen is started to be introduced into the material. A 3-blade propeller stirring shaft with a total blade diameter of 75 mm is used. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. After a reaction time of about 360 h, the methanol is distilled off.

[0078] Complete conversion was checked by NMR using residual methanol content.

[0079] During the distillation, stirring (rpm 100) becomes difficult because the viscosity becomes very high. The torque increases from 0-5 Ncm to 10-22 Ncm. The viscosity can be reduced to obtain a homogeneous reaction mixture by adding o-xylene (0.1-0.4 L), by which the torque is reduced to 5-7 Ncm. During the reaction o-xylene is carried out as an aerosol at the top of the reactor and must be replenished in several portions. The total amount of o-xylene (100%; 1.0 L; 8.3 mol).

[0080] At the end of the distillation, 50 mL (anhydrous / 100%) toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form.

[0081] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0082] For washing, the slurry is pressurized onto the filter. The residue is transferred to the cake with 25 mL of toluene (anhydrous), and the filter cake is washed three times with 25 mL of toluene (anhydrous) each time. Then, the filter cake is washed twice with 100 mL (dry, water content is <10 ppm) of MTBE each time. The final product is dried under inert gas and vacuum (RT to 35 ° C, p = 0.05 bara, t = 20 h). Yield: 92.8% Titration purity: 98.7 wt %.

[0083] In the presence of tetraethylene glycol dimethyl ether, benzyloxyethanol reacts to form potassium benzyloxyethanol.

[0084]

[0085] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 311.2 g of benzyloxyethanol (99%; 2.0 mol; 1 equivalent) are charged into the reactor and 143.4 g of potassium methoxide (98.95%; 2.0 mol; 1 equivalent) are added. After the addition of the raw materials, the reactor is (re) inerted. The reaction is heated to 120° C. with continuous stirring and nitrogen is started to be introduced into the material. A 3-blade propeller stirring shaft with a total blade diameter of 75 mm is used. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. After a reaction time of about 264 h, the methanol is distilled off.

[0086] Complete conversion was checked by NMR using residual methanol content.

[0087] During the distillation, stirring (rpm 100) became difficult because the viscosity became very high. The torque increased from 0-6 Ncm to 10-26 Ncm. The viscosity could be reduced to obtain a homogeneous reaction mixture by adding tetraglyme (0.1 L), by which the torque was reduced to 7-14 Ncm. Tetraglyme was carried out as an aerosol at the top of the reactor during the reaction and had to be replenished in several portions. The total amount of tetraglyme (100%; 0.6 L; 2.1 mol).

[0088] At the end of the distillation, 50 mL (anhydrous / 100%) toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form.

[0089] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0090] For washing, the slurry was pressurized onto the filter. The residue was transferred to the cake with 50 mL of toluene (anhydrous), and the filter cake was washed twice with 100 mL of toluene (anhydrous) each time. Afterwards, the filter cake was washed twice with 300 mL of dry MTBE each time. The final product was dried by applying an inert gas and vacuum. Yield: 99.65% Titration purity: 87.9 wt %.

[0091] Benzyloxyethanol reacts with potassium tert-butoxide to form potassium benzyloxyethanol

[0092]

[0093] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 264.5 g of benzyloxyethanol (99%; 1.7 mol; 1 equivalent) are charged to the reactor and 195.0 g of potassium tert-butoxide (98%; 1.7 mol; 1 equivalent) are added. After the addition of the starting materials, the reactor is (re) inerted. The reaction is heated to 110° C. with continuous stirring and nitrogen is introduced into the material. A 3-blade propeller stirring shaft with a total blade diameter of 75 mm is used. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. Tert-butanol is distilled off for about 120 h reaction time.

[0094] Complete conversion was checked by NMR using residual methanol content.

[0095] During the distillation, stirring (rpm 100) becomes difficult because the viscosity becomes very high. The torque increases from 3-8 Ncm to 15-30 Ncm. The viscosity can be reduced by adding n-dodecane (0.1-0.2 L), obtaining a homogeneous reaction mixture, by which the torque is reduced to 1-8 Ncm. During the reaction, n-dodecane is taken out as an aerosol at the top of the reactor and must be replenished in several portions. The total amount of n-dodecane (100%; 0.75 L; 3.3 mol).

[0096] At the end of the distillation, 50 mL (anhydrous / 100%) toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form.

[0097] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0098] For washing, the slurry was pressurized onto the filter. The residue was transferred to the cake with 50 mL of toluene (anhydrous), and the filter cake was washed twice with 50 mL of toluene (anhydrous) each time. Afterwards, the filter cake was washed twice with 200 mL of dry MTBE each time. The final product was dried by applying an inert gas and vacuum. Yield: 90.5% Titration purity: 98.9 wt %.

[0099] Diethylene glycol monobenzyl ether reacts to form potassium diethylene glycol monobenzyl ether (potassium-diethylenglycolmonobenzylether)

[0100] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 277.0 g of diethylene glycol monobenzyl ether (99%; 1.4 mol; 1 equivalent) are charged to the reactor and 98.0 g of potassium methoxide (98%; 1.4 mol; 1 equivalent) are added. After the addition of the raw materials, the reactor is (re) inerted. The reaction is heated to 110° C. with continuous stirring and nitrogen is started to be introduced into the material. A 3-blade propeller stirring shaft with a total blade diameter of 75 mm is used. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. After a reaction time of about 72 h, the methanol is distilled off.

[0101] Complete conversion was checked by NMR using residual methanol content.

[0102] During the distillation, stirring was performed (rpm 100). The reaction mass was a viscous liquid. The torque increased from 1-2 Ncm to 6-8 Ncm. The viscosity could be reduced by adding n-dodecane (0.1-0.2 L), obtaining a homogeneous reaction mixture, by which the torque was reduced to 1-5 Ncm. During the reaction, n-dodecane was taken out as an aerosol at the top of the reactor and had to be replenished in several portions. The total amount of n-dodecane (100%; 0.75 L; 3.3 mol).

[0103] After the reaction, the product exists in the form of a dark red highly viscous liquid. Yield: 74.8% NMR purity: 91.3 wt%.

[0104] In the presence of potassium tert-butoxide, the stirring blade becomes an anchor stirrer, and 2-tert-butoxyethanol reacts to form potassium 2-tert-butoxyethanol.

[0105]

[0106] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 241.1 g of 2-tert-butoxyethanol (98%; 2.0 mol; 1 equivalent) are charged to the reactor and 250.4 g of potassium tert-butoxide (98%; 2.0 mol; 1 equivalent) are added. After the addition of the raw materials, the reactor is (re) inerted. The reaction is heated to 110° C. with continuous stirring and nitrogen is started to be introduced into the material. An anchor stirrer with a total blade diameter of 95 mm is used for the stirring shaft. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. Tert-butanol is distilled off for about 26 h reaction time.

[0107] Complete conversion was checked by NMR using residual methanol content.

[0108] During the distillation, stirring (rpm 100) becomes difficult because the viscosity becomes very high. The torque increases from 10-15 Ncm to 30-50 Ncm. The viscosity can be reduced to obtain a homogeneous reaction mixture by adding n-dodecane (0.1-0.2 L), by which the torque is reduced to 2-4 Ncm. During the reaction, n-dodecane is carried out as an aerosol at the top of the reactor and must be replenished in several portions. The total amount of n-dodecane (100%; 0.4 L; 1.8 mol)

[0109] At the end of the distillation, 50 mL (anhydrous / 100%) of toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to a low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form. Sufficient dilution with toluene is required for transfer to the filtration equipment, so the toluene content must be adjusted to suit the existing filtration equipment.

[0110] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0111] For washing, the slurry was pressurized onto the filter. The residue was transferred to the cake with 50 mL of toluene (anhydrous), and the filter cake was washed twice with 100 mL of toluene (anhydrous) each time. Afterwards, the filter cake was washed twice with 200 mL of dry MTBE each time. The final product was dried by applying an inert gas and vacuum. Yield: 86.2% Titration purity: 99.0 wt %.

[0112] In the presence of potassium tert-butoxide, the stirring blade becomes an anchor stirrer, and triethylene glycol reacts to form dipotassium triethylene glycol (dipotassium-triethylenglycolat)

[0113]

[0114] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 379.2 g of triethylene glycol (99%; 2.5 mol; 1 equivalent) are charged into the reactor and 572.2 g of potassium tert-butoxide (98%; 5.0 mol; 2 equivalents) are added. After the addition of the raw materials, the reactor is (re) inerted. The reaction is heated to 110° C. with continuous stirring and nitrogen is started to be introduced into the material. An anchor stirrer with a total blade diameter of 95 mm is used for the stirring shaft. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. Tert-butanol is distilled off for about 77 h reaction time.

[0115] Complete conversion was checked by NMR using residual methanol content.

[0116] During the distillation, stirring (rpm 100) becomes difficult because the viscosity becomes very high. The torque increases from 3-15 Ncm to 15-37 Ncm. The viscosity can be reduced by adding a mixture of n-dodecane and tetraethylene glycol dimethyl ether (v / v 50 / 50) (0.1-0.2 L), obtaining a homogeneous reaction mixture, by which the torque is reduced to 15-20 Ncm. The mixture is taken out as an aerosol at the top of the reactor during the reaction and must be replenished in several portions. The total amount of n-dodecane (100%; 0.4 L).

[0117] At the end of the distillation, 50 mL (anhydrous / 100%) toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form.

[0118] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0119] For washing, the slurry is pressurized onto a filter (filter area 7-14 cm 2 , resulting in a filter cake height of 16-8 cm). The residue was transferred to the cake with 50 mL of toluene (anhydrous), and the filter cake was washed four times with 100 mL of toluene (anhydrous) each time. Afterwards, the filter cake was washed twice with 600 mL of dry MTBE each time. The final product was dried by applying an inert gas and vacuum. Yield: 95.7% Titration purity: 98.8% by weight.

[0120] In the presence of potassium tert-butoxide, 2-methoxyethanol reacts to form potassium 2-methoxyethanol

[0121]

[0122] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 305.0 g of triethylene glycol (99%; 4.0 mol; 1 equivalent) are charged into the reactor and 458.0 g of potassium tert-butoxide (98%; 4.0 mol; 1 equivalent) are added. The reactor is (re) inerted after the addition of the raw materials. The reaction is heated to 120° C. with continuous stirring and nitrogen is started to be introduced into the material. A 3-blade propeller stirring shaft with a total blade diameter of 95 mm is used. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. Tert-butanol is distilled off for about 50 h reaction time.

[0123] Complete conversion was checked by NMR using residual methanol content.

[0124] During the distillation, stirring (rpm 100) becomes difficult because the viscosity becomes very high. The torque increases from 3-5 Ncm to 15-20 Ncm. The viscosity can be reduced by adding n-dodecane (0.1-0.2 L), obtaining a homogeneous reaction mixture, by which the torque is reduced to 2-5 Ncm. During the reaction the mixture is carried out as an aerosol at the top of the reactor and must be replenished in several portions. The total amount of n-dodecane (100%; 0.5 L).

[0125] At the end of the distillation, 50 mL (anhydrous / 100%) toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form.

[0126] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0127] For washing, the slurry was pressurized onto the filter. The residue was transferred to the cake with 50 mL of toluene (anhydrous), and the filter cake was washed twice with 50 mL of toluene (anhydrous) each time. Afterwards, the filter cake was washed twice with 200 mL of dry MTBE each time. The final product was dried by applying an inert gas and vacuum. Yield: 93.7% Titration purity: 97.1% by weight.

[0128] In the presence of potassium methoxide, pentaerythritol reacts to form tetrapotassium pentaerythritol

[0129]

[0130] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 277.8 g of pentaerythritol (99%; 2.0 mol; 1 equivalent) are charged into the reactor and 567.0 g of potassium tert-butoxide (98%; 8.1 mol; 4 equivalents) are added. The reactor is (re) inerted after the addition of the raw materials. The reaction is heated to 145° C. with continuous stirring and nitrogen is started to be introduced into the material. A 3-blade propeller stirring shaft with a total blade diameter of 95 mm is used. The nitrogen flow is maintained at approximately 100 L / h of dry nitrogen throughout the distillation. After a reaction time of about 390 h, methanol is distilled off.

[0131] Complete conversion was checked by NMR using residual methanol content.

[0132] During the distillation, stirring (rpm 100) becomes difficult because the viscosity becomes very high. The torque increases from 3-5 Ncm to 15-20 Ncm. The viscosity can be reduced by adding a mixture of n-dodecane and diglyme (v / v 50 / 50) (0.1-0.3 L), obtaining a homogeneous reaction mixture, by which the torque is reduced to 2-8 Ncm. The mixture is taken out as an aerosol at the top of the reactor during the reaction and must be replenished in several portions. The total amount of n-dodecane (100%; 1.6 L).

[0133] At the end of the distillation, 50 mL (anhydrous / 100%) toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form.

[0134] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0135] For washing, the slurry was pressurized onto the filter. The residue was transferred to the cake with 50 mL of toluene (anhydrous), and the filter cake was washed three times with 50 mL of toluene (anhydrous) each time. Afterwards, the filter cake was washed twice with 200 mL of dry MTBE each time. The final product was dried by applying an inert gas and vacuum. Yield: 55.2% Titration purity: 69.4% by weight.

[0136] For washing, the slurry was pressure loaded onto the filter and the filter cake was washed twice with a non-polar solvent. The final product was dried by applying an inert gas and vacuum.

[0137] In the presence of n-dodecane, benzyloxyethanol reacts to form benzyloxyethanol salt

[0138]

[0139] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert atmosphere (dry atmosphere), 627.7 g of benzyloxyethanol (98%; 4 mol; 1 equivalent) are charged into the reactor and 166.8 g of potassium methoxide (98.95%; 4 mol; 1 equivalent) are added. After the addition of the raw materials, the reactor is (re) inerted. The reaction is heated to 110° C. and nitrogen is introduced into the melt. The nitrogen flow is maintained at about 100 L / h of dry nitrogen throughout the distillation. After a reaction time of about 44 h, the methanol is distilled off.

[0140] Complete conversion was checked by NMR using residual methanol content.

[0141] Stirring becomes difficult during the distillation because the viscosity becomes very high (indicated by the increase in stirrer torque). The viscosity can be reduced by adding n-dodecane (100%; 0.16 kg; 0.215 L) to obtain a homogeneous reaction mixture. During the reaction, n-dodecane is carried out as an aerosol at the top of the reactor and has to be replenished in several portions. The total amount of n-dodecane (100%; 250 ml; 1.1 mol; 1.1 eq.)

[0142] At the end of the distillation, 250 mL (anhydrous / 100%) toluene is added for slurry preparation (at about 100°C and full speed stirring). Toluene must be dried to a low water content (e.g., with molecular sieves, AlOx or other suitable methods) before addition, or purchased in anhydrous form. Sufficient dilution with toluene is required for transfer to the filtration equipment, so the toluene content must be adjusted to suit the existing filtration equipment.

[0143] The cooling rate (for laboratory tests) was kept between -0.1 K / min and 1 K / min, down to 20° C. The cooling program must be adapted to the equipment under consideration.

[0144] In order to wash, the slurry is pressurized and loaded onto the filter. The residue is transferred to the cake with 125mL toluene (anhydrous), and the filter cake is washed twice with 125mL toluene (anhydrous) each time. Afterwards, the filter cake is washed twice with 200mL dry MTBE each time. By applying inert gas and vacuum, the final product is dried.

[0145] The bulk density (dry product) is about 0.94 kg / l.

[0146] In the presence of potassium tert-butoxide, benzyloxyethanol reacts in a continuous distillation to form potassium benzyloxyethanol.

[0147]

[0148] Before carrying out the reaction, the required reaction equipment is inerted and kept dry. Under an inert and dry atmosphere, 232.7 g of benzyloxyethanol (99%; 1.5 mol; 1 equivalent) are charged into the reactor and 191.6 g of potassium tert-butoxide (98%; 1.5 mol; 1 equivalent) are added, followed by inerting the reactor. The reaction is heated to 110° C. under continuous stirring and nitrogen is introduced into the material. An anchor stirrer with a total blade diameter of 90 mm is used. Toluene is continuously introduced into the reaction mass (1 mL / min) using a capillary. The nitrogen flow is maintained at approximately 100 L / h of dry nitrogen during the entire distillation. After a reaction time of about 5.5 h, tert-butanol and toluene are distilled off, during which a thicker suspension is obtained. The reaction is terminated by lowering the temperature to 20° C., and the mass is diluted after 6 hours and can be discharged homogeneously from the reaction vessel.

[0149] The cooling rate is kept between -0.1 K / min and 1 K / min to a minimum of 20° C. The cooling program must be adapted to the equipment under consideration.

[0150] The slurry was pressurized onto the filter. The residue was transferred with 50 mL of toluene (anhydrous), and the filter cake was washed twice with 50 mL of toluene (anhydrous) each time. Afterwards, the filter cake was washed twice with 200 mL of dry MTBE each time. The final product was dried under inert conditions and under applied vacuum. Yield: 90.1% Titration purity: 99.1% by weight.

Claims

1. A method for preparing an alkali metal alkoxide, wherein The following steps are involved: i) providing an organic compound having at least one -OH group and a molecular weight of 75 g / mol to 750 g / mol in a reaction vessel in an inert atmosphere; ii) Join C 1-6 an alkali metal alcoholate to obtain a reaction mixture; iii) heating the reaction mixture of step ii) to 25°C to 180°C under stirring to obtain an alkali metal alkoxide and C 1-6 alcohol; and iv) distilling off the obtained C 1-6 Alcohol; wherein during the distillation, at least one non-polar solvent is continuously or batchwise added to the mixture, the non-polar solvent having a boiling point higher than the alcohol obtained.

2. The method according to claim 1, wherein the organic compound having at least one -OH group is selected from substituted or unsubstituted aliphatic or aromatic hydrocarbons, silyl ethers, polyols, ethers and polyethers or mixtures thereof.

3. The method according to any one of the preceding claims, wherein the C 1-6 The alkali metal alcoholate is selected from potassium methoxide, potassium ethoxide, potassium 2-methylpropan-2-olate, potassium propan-2-olate, potassium propan-1-olate, potassium butan-2-olate and potassium tert-butoxide.

4. The process according to any one of the preceding claims, wherein the at least one solvent is non-polar and aprotic, such as aromatic hydrocarbons, aliphatic hydrocarbons, ether solvents.

5. A process according to any one of the preceding claims, wherein the reactor comprises a rotating element for stirring; preferably The at least one non-polar solvent is added when the torque M of the rotating element increases by at least 1.5 times, and the torque M decreases by at least 1.5 times after the at least one non-polar solvent is added.

6. The method according to any one of the preceding claims, wherein the at least one non-polar solvent is present in an amount of 1 ml / mmol to 20 ml / mmol relative to the organic compound having at least one -OH group and a molecular weight of 75 g / mol to 750 g / mol.

7. A process according to any one of the preceding claims, wherein the reaction time is at least 3 hours.

8. The process according to any one of the preceding claims, wherein the at least one non-polar solvent is washed out with a volatile non-polar solvent after the reaction.

9. The method according to any one of the preceding claims, wherein the organic compound having at least one -OH group and a molecular weight of 75 g / mol to 750 g / mol is 1-6 The alkali metal alcoholate is present in a molar ratio of 2:1 to 1:1.

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