Method for producing alkaline o-carbonate or alkaline p-carbonate

Abstract

The present invention relates to a method for preparing an alkaline o-cresol acid salt or an alkaline para-xylenol acid salt of o-cresol or para-xylenol. It has been shown that this process for reacting a compound of formula (II) with sodium hydroxide or potassium hydroxide using an extruder is very advantageous and enables significantly faster reaction times and continuous processes. Formula (II) wherein R is H or CH3, and Y is SO3H or SO3-X + or Cl, and X is Na or K, preferably Na.

Description

Technical Field

[0001] This invention relates to the field of producing o-cresol or p-xylenol. Background Technology

[0002] The compounds o-cresol (=2-methylphenol) and p-xylenol (=2,5-dimethylphenol) are high-value ingredients used for different purposes. Xylenol is used as a raw material for pesticides, antioxidants, or pharmaceuticals.

[0003] Cresol is a precursor or synthetic intermediate for other compounds and materials, including plastics, pesticides, pharmaceuticals, and dyes.

[0004] The compound o-cresol is of great interest because it is used as an industrial solvent and in disinfectants and fungicides, or in the manufacture of synthetic resins, herbicides, pesticides, dyes, pharmaceuticals, antioxidants, perfumes and other chemicals, and as a food antioxidant, textile scouring agent, surfactant, metal cleaner and ore flotation agent, and as a component in cleaning compounds, degreasers, paints and paint removers, adhesives, fiber treatments, wood preservatives and cutting oils.

[0005] The compound xylenol is used to synthesize pH indicators such as xylenolphthalein, xylenol blue, or bromoxylenol blue, as well as the main raw material for drugs and gemfibrozil, which can be used as a drug to treat dyslipidemia.

[0006] The compound p-xylenol is of key significance for the large-scale industrial synthesis of 2,3,6-trimethylphenol, 2,3,5-trimethylphenol, 2,3,5-trimethylhydroquinone, or α-tocopherol.

[0007] Currently, 2,5-dimethylphenol is prepared by alkali melting of sulfonated p-xylene using an intermittent method.

[0008] Alkali melting is a process that has raised concerns about corrosion and safety, especially when the method is batch.

[0009] For example, CN 102627531 discloses such an intermittent method.

[0010] CN 114805034 discloses a method in which, in a first step, sodium 2,5-dimethylbenzenesulfonate and a strong base are mixed in a roke dryer, and after grinding, sieving, and drying for 5 hours, a very fine powder (1-5 micrometers) is obtained. Then, in a second step, the powder is transferred to a spiral reactor and reacted at high temperature for a prolonged period of 1 to 5 hours to obtain p-xylenol by acid quenching in a third step. Due to the use of a roke dryer and a spiral reactor, the disclosed method is very slow and requires the preparation of a fine powder, especially in the first step.

[0011] In the field of thermoplastics, it is known to use extruders to mix and compound thermoplastic materials. Summary of the Invention

[0012] The problem to be solved is to find a method for preparing basic o-cresol or basic p-cresol in a rapid and efficient manner, without having to go through a lengthy drying and grinding process to form a very fine powder.

[0013] Surprisingly, it has been found that the method of claim 1 provides a solution to this problem.

[0014] Using an extruder to melt and react the compound of formula (II) and the base XOH is highly advantageous because it eliminates the need to grind sodium 2,5-dimethylbenzenesulfonate and the base XOH prior to the reaction in step b), and is significantly faster than known methods (only a few minutes instead of several hours). Despite the shorter reaction time, high yields and high conversion rates are observed. The amount of undesirable degradation products is reduced due to the shorter exposure to high temperatures in reaction step b).

[0015] The method of this invention is highly advantageous considering the reduction in energy costs, time costs, and safety risks during the production process. These advantages become even more pronounced because the method enables a fully continuous process.

[0016] Other aspects of the invention are the subject of the other independent claims. Particularly preferred embodiments are the subject of the dependent claims. Invention Details

[0018] In a first aspect, the present invention relates to a method for preparing a compound of formula (I) from a compound of formula (II),

[0019]

[0020] The method includes the following steps: a) Provides compounds of formula (II) b) At a temperature above the melting point of XOH, particularly between 320°C and 450°C, more particularly between 330°C and 450°C, even more particularly between 360°C and 450°C, preferably between 360°C and 420°C, more preferably between 380°C and 400°C, the compound of formula (II) is melted and reacted with XOH in extruder 1 to produce the compound of formula (I); The characteristic feature is that R is H or CH3, and Y is SO3H or SO3. - X +Or Cl, and X is Na or K, preferably Na.

[0021] For clarity, some terms used in this document are defined as follows: In cases where the same symbol or group exists in several formulas, the definition of the group or symbol in the context of a particular formula in this document also applies to other formulas containing the same symbol.

[0022] The melting point of a particular substance in this article is used as the temperature at which the substance melts at ambient temperature (23°C) and pressure (1013 mbar).

[0023] The term “substantially anhydrous” as used in this article means that the substance under discussion contains only trace amounts of water, in particular no more than 10 wt%.

[0024] Step a)

[0025] In step a), a compound of formula (II) is provided.

[0026] The compounds of formula (II) are selected from the group consisting of compounds of formulas (IA), (IB) and (IC).

[0027] Compounds of formula (II-A) can be prepared by sulfonation of compounds of formula (III), particularly by reaction of sulfuric acid with compounds of formula (III). Concentrated sulfuric acid is particularly suitable.

[0028]

[0029] The reaction typically produces a mixture of isomers containing a compound of formula (II-A). Those skilled in the art will recognize that the amount of the compound of formula (II-A) in the mixture is strongly dependent on the reaction conditions during sulfonation.

[0030] In one embodiment, an isomer mixture comprising a compound of formula (II-A) is used in the method of the present invention. In another embodiment, isomer (II-A) is isolated from the mixture and isomer (II-A) is used in the method of the present invention.

[0031] Compounds of formula (II-B) can be prepared by neutralizing compounds of formula (II-A), particularly as described in more detail later herein.

[0032] The compounds of formula (II-C) can be prepared by reacting the compounds of formula (III) with chlorine.

[0033] The reaction is known to those skilled in the art and typically produces a mixture of isomers of a compound containing formula (II-C). In one embodiment, the mixture of isomers of a compound containing formula (II-C) is used in the method of the present invention. In another embodiment, isomer (II-C) is isolated from the mixture and used in the method of the present invention.

[0034] Preferably, the compound of formula (II) is a compound of formula (II-A) or a compound of formula (II-B).

[0035] The compounds of formula (II) are selected from the group consisting of:

[0036] Preferably, R = CH3.

[0037] Therefore, the preferred compound of formula (II) is the compound of formula (II-O), and the preferred compound of formula (I) is the compound of formula (IO).

[0038] Furthermore, preferably, Y = SO3 - X + Especially SO3 - Na + .

[0039] More preferably, the compound of formula (II) is a compound of formula (II-B), especially (II-B2), especially (II-BB).

[0040]

[0041] Therefore, the preferred compound of formula (I) is the compound of formula (IA), and more preferably the compound of formula (I-BB).

[0042]

[0043] Among potassium salts, the most preferred compound of formula (II) is the compound of formula (II-CC), and the most preferred compound of formula (I) is the compound of formula (I-CC).

[0044] Reaction step b)

[0045] In step b), the compound of formula (II) is melted and reacted with XOH in extruder 1 at a temperature above the melting point of XOH, particularly between 320°C and 450°C, more particularly between 330°C and 450°C, even more particularly between 360°C and 450°C, preferably between 360°C and 420°C, and more preferably between 380°C and 400°C, to produce the compound of formula (I).

[0046] The melting point of NaOH is approximately 320℃, while the melting point of KOH is 360℃.

[0047] Therefore, it is obvious that, as part of the aforementioned temperature range, the temperature range between 320°C and 360°C is only suitable for the case where NaOH is used for the reaction.

[0048] Preferably, step b) of melting and reacting the compound of formula (II) with XOH is carried out in the presence of a molar excess of XOH, such that the molar ratio of XOH and / or the compound of formula (II) is >2, particularly between 2 and 4, preferably between 2 and 3, and more preferably between 3 and 2.5.

[0049] More preferably, the molar ratio is in the range of 2.01 to 3.99, more preferably in the range of 2.01 to 2.99, and even more preferably in the range of 2.01 to 2.49.

[0050] A mixture of NaOH and KOH can also be used.

[0051] However, the preferred method is to use NaOH alone.

[0052] Temperatures above 450°C in step b) are, in principle, possible.

[0053] Although higher temperatures will result in faster reaction times, thus allowing for shorter residence times in the extruder in principle, it is recommended that the reaction in step b) not be carried out at excessively high temperatures, as this leads to the formation of higher amounts of degradation products of compounds of formula (I) or (II). The formation of such degradation products is particularly pronounced if extended residence times are used for compounds of formula (II) or (I), respectively.

[0054] The residence time of the compounds of formula (II) or (I) is controlled by the extrusion speed (i.e., the rotational speed of the extruder screw). If the time is too short, the reaction is incomplete, and a significant amount of unreacted compounds of formula (II) is observed in the product leaving the extruder. If the time is too long, especially at elevated temperatures, particularly above 450°C, there is a risk of undesirable byproducts forming through the thermal degradation of the compounds of formula (I) or (II).

[0055] The reaction in step b) takes place inside the extruder.

[0056] Extruder 1 includes

[0057] At least including: -Shell 6 - Cavity 5 inside the housing 6 - The extruder screw 7 inside the cavity 5 -Inlet 2 for compounds of formula (II) -Exit 3 for compounds of formula (I) - A mixture of XOH and the compound of formula (II) inside the cavity 5.

[0058] In other words, an extruder containing XOH and a compound of formula (II) represents an apparatus for producing a compound of formula (I).

[0059] The compound of formula (II) can be NaOH, which can be introduced into extruder 1 through inlet 2 of the extruder.

[0060] The alkali XOH (preferably NaOH) can be introduced into the extruder 1 as a mixture with the compound of formula (II) through the inlet of extruder 2 or preferably through a separate inlet 4 for KOH and / or NaOH.

[0061] Preferably, XOH is transferred to the extruder in the form of solid XOH or as a melt of XOH. More preferably, XOH is introduced into the extruder as a melt.

[0062] Preferably, the extruder 1 further includes a heating element 9, which allows for temperature regulation of the reaction mixture of XOH and the compound of formula (II) within the extruder 1. This is particularly advantageous if the reaction mixture exhibits a temperature gradient extending from a lower temperature near the inlet of the extruder inlet 2 to a higher temperature at the extruder outlet 2. Preferably, the temperature gradient difference is at least 20 K, and more preferably at least 40 K.

[0063] Therefore, it is preferable that the temperature of the material in the inlet 2 region of the extruder 1 is lower than the temperature of the material in the outlet 3 region of the extruder 1.

[0064] During the reaction, some gas is generated. Therefore, it is further preferred that the extruder includes at least one degassing outlet 10. This degassing outlet allows the gas to escape from the extruder. The location of this degassing outlet 10 along the extruder axis is chosen such that the gas formed during the reaction does not create high pressure inside the extrudate, which may be critical from a safety perspective. Typically, the degassing outlet 10 includes a device for controlling pressure release, such as a pressure control valve 11.

[0065] Extruder 1 is a single-screw or multi-screw extruder.

[0066] Compared to single-screw extruders, multi-screw extruders are more effective at providing a homogeneous mixture of reactants. While the mixing efficiency of a single-screw extruder can be improved by using mixing elements, it is not as efficient as with a multi-screw extruder. A wider variety of multi-screw extruders are available, which can vary in structure and may have parallel or conical screws that can rotate in the same direction (co-rotation) or opposite directions (counter-rotation) with varying degrees of intermeshing. Unlike helical reactors, which have no moving internal parts and therefore mix solely through the fluid flow itself, extruders have actively rotating screws that are highly efficient in mixing. Therefore, extruders are also capable of handling very coarse materials to obtain homogeneous mixtures, unlike helical reactors. Extruders are known to be very efficient.

[0067] Preferably, the extruder 1 is a twin-screw or three-screw extruder.

[0068] Neutralization steps

[0069] When the compound of formula (II) is a compound of formula (II-B), particularly a compound of formula (II-B2), and preferably a compound of formula (II-BB), the compound is preferably prepared by neutralizing a compound of formula (II-A) or (II-A2), respectively.

[0070]

[0071] Neutralization is preferably carried out by reaction with NaOH and / or KOH, preferably NaOH.

[0072] The neutralization of the compound of formula (II-B) can be carried out in the extruder or outside the extruder.

[0073] In one of these implementations, the neutralization reaction takes place in an extruder.

[0074] Therefore, preferably, the compound of formula (II) is the compound of formula (II-B) prepared by step a0). a0) At a temperature between 100°C and 200°C, particularly between 100°C and 180°C, even more particularly between 100°C and 150°C, preferably between 110°C and 130°C, in an extruder, a compound of formula (II-A), particularly a compound of formula (II-A2), is neutralized with XOH to form a compound of formula (II-B).

[0075] In one embodiment, the neutralization step a0) is carried out in the same extruder as step b). However, in this case, it is preferable that the neutralization is carried out near the section close to the extruder inlet, preferably at a lower temperature than that of reaction step b), which occurs further downstream in the extruder, i.e., closer to the extruder outlet.

[0076] However, in a preferred manner, the neutralization step (a0) is preferably carried out in a separate extruder.

[0077] In other words, preferably, the neutralization step (a0) is carried out in the first extruder 1a, the melt reaction step (b) is carried out in the second extruder 1b, and the compound of formula (II) is transferred from the outlet 3a of the first extruder 1a to the inlet 2b of the second extruder 1b.

[0078] Preferably, the material transfer between the first extruder 1a and the second extruder 1b is carried out via an environmentally enclosed connecting device 12.

[0079] This makes it possible to produce compounds of formula (I) from compounds of formula (II) as a continuous process.

[0080] Preferably, step a0) of neutralizing the compound of formula (II) with sodium hydroxide and / or potassium hydroxide is carried out in the presence of a molar excess of XOH, such that the molar ratio of XOH to the compound of formula (II) is >1, particularly between 1 and 2, preferably between 1 and 1.5, and more preferably between 1 and 1.25.

[0081] More preferably, the molar ratio is in the range of 1.01 to 1.99, more preferably in the range of 1.01 to 1.49, and even more preferably in the range of 1.01 to 1.24.

[0082] Compounds of formula (II-A), particularly (II-A2), are fed into an extruder, preferably at a temperature between 100°C and 200°C, particularly between 100°C and 180°C, even more particularly between 100°C and 150°C, and most preferably between 110°C and 130°C. At this temperature, compounds of formula (II-A), particularly (II-A2), form a viscous liquid.

[0083] The alkali XOH is fed into the extruder, preferably as beads or pellets of a few millimeters (such as those commercially available).

[0084] Because of the use of an extruder, coarse particles of compounds of formula (II-A) or (II-A2) or XOH up to several millimeters in size can be used without any problems. Therefore, long-term grinding or pulverization is not required.

[0085] It is also possible that a mixture of NaOH and KOH can be used for neutralization step a0).

[0086] However, the preferred method is to use NaOH alone.

[0087] Stoichiometric amounts of water are formed through a neutralization reaction between a compound of formula (II-A) or (II-A2) and the base XOH.

[0088] Since the presence of a large amount of water is detrimental to the reaction in step b), the neutralization step a0) is carried out at an elevated temperature, i.e., above 100°C. Temperatures above 200°C in step a0) are theoretically possible. However, it is recommended not to carry out neutralization a0) at excessively high temperatures, as this could lead to a significant buildup of gas pressure, potentially causing safety issues.

[0089] When reaction step b) is carried out at elevated temperatures, it is highly recommended that the amount of water forming vapor (i.e., water vapor) at the reaction temperature be avoided or minimized as much as possible in the starting products, particularly in the compounds of formula (II) and XOH. Since NaOH and KOH are highly hygroscopic, it is preferable to store the compounds in water- and vapor-tight containers before use and to carry out the entire method of the invention under a closed and / or inert atmosphere. It is also preferable that the starting materials are anhydrous or at least substantially anhydrous.

[0090] The residence time of the compounds of formula (II) or (I) is controlled by the extrusion speed (i.e., the rotational speed of the extruder screw). If the time is too short, the reaction is incomplete, and a significant amount of unreacted compounds of formula (II) is observed in the product leaving the extruder. If the time is too long, especially at elevated temperatures, particularly above 450°C, there is a risk of undesirable byproducts forming through the thermal degradation of the compounds of formula (I) or (II).

[0091] It has been observed that the residence time in extruder 1a used for neutralization step a0) can be significantly shorter than the residence time in extruder 1b used for reaction step b), because neutralization is a very fast reaction, which is significantly faster than the reaction in step b) even at lower temperatures.

[0092] It has been found that the residence time in the first extruder 1a is typically less than 1 minute, particularly between 30 seconds and 2 minutes, and preferably between 30 seconds and 60 seconds.

[0093] It has been found that the residence time in the second extruder 1b is typically several minutes, particularly between 3 and 30 minutes, and preferably between 10 and 20 minutes.

[0094] To better time steps a0) and b) within the framework of a continuous method, the residence time in the first extruder can be extended so that the residence times in both extruders 1a and 1b are the same, typically several minutes, particularly between 3 and 30 minutes, and preferably between 10 and 20 minutes. This extension of the residence time in the first extruder 1a is not particularly detrimental because the decomposition reaction is not significant at the relatively low temperature in the first extruder 1a.

[0095] To optimize productivity and reduce production costs, the entire method of the present invention is preferably a continuous method. As described above, this objective can be easily achieved through the described features.

[0096] In a preferred embodiment, the material exiting extruder 1, and particularly the second extruder 1b, is transferred to a heated container, specifically a heated tubular reactor, tubular reactor, or spiral reactor. Advantageously, the heated container is heated to the same temperature range as the second extruder. By allowing the product to remain in the heated container for an additional time, higher yields and / or allowing the extruder to operate at higher extrusion speeds can be obtained, resulting in higher overall product output for the process equipment.

[0097] Preferably, after step b), the reaction product, i.e., the compound of formula (I), especially the compound of formula (I) together with an excess of molten XOH, is transferred to a container 13 containing water, particularly to an aqueous solution of sulfite, preferably an aqueous solution of Na₂SO₃. Due to its limited solubility in water, the compound of formula (I) can be readily separated, for example, by a filter or frit. If desired, the thus separated compound of formula (I) can be further purified.

[0098] Preferably, the transfer is achieved by a connecting device 22, which is, for example, a pipe between the outlet of the extruder 3 (particularly the outlet of the second extruder 3b) and the water-containing container 13.

[0099] To allow for a smooth reaction and a constant mass flow (preferably continuously), it is preferable to use a pump to feed the starting product and / or to accelerate the exit of the formed product from the extruder. Preferred pumps are gear pumps or screw pumps.

[0100] It will be apparent to those skilled in the art that all components of the extruder, the eventual pipes, the tubing leading to or leaving the extruder 1, or the pumps involved in the mass flow (all in contact with the starting product, reaction mixture, or product) are selected to be made of materials that are chemically resistant to the respective chemicals in contact at the temperatures used in operation.

[0101] Compounds of formula (I), especially formula (I-BB) or (I-CC), preferably (I-BB), can be used to prepare compounds of formula (IV), especially (IV-B).

[0102]

[0103] Therefore, another aspect of the present invention is a method for manufacturing compounds of formula (IV), particularly compounds of formula (IV-B).

[0104] The method is characterized by comprising the steps of...

[0105] i) Prepare compounds of formula (I) and compounds of particular formula (I-0) by the methods described and discussed above.

[0106] Next are the steps

[0107] c) Acidifying compounds of formula (I) and, in particular, (I-0), to obtain compounds of formula (IV), especially compounds of formula (IV-B).

[0108] in

[0109] R is H or CH3, preferably CH3.

[0110] The acid used for acidification in step c) is usually an inorganic acid, especially hydrochloric acid or sulfuric acid, preferably dilute HCl or H2SO4.

[0111] Advantageously, the compound of formula (I) is acidified in water to obtain a pH of 5 or lower.

[0112] It is particularly suitable to use gaseous SO2 or CO2 to form an "aqueous SO2 solution" or "CO2 solution", which are sulfurous acid or carbonic acid, respectively.

[0113] As shown above, the use of an extruder is a key element for the advantages of the described method, and is highly advantageous for the method of preparing compounds of formula (I) or formula (IV).

[0114] Therefore, in another aspect, the present invention relates to the use of extruder 1 in the manufacture of compounds of formula (I) or (IV),

[0115] in

[0116] R is H or CH3, preferably CH3, and X is Na or K, preferably Na.

[0117] Preferred embodiments of the compounds of formula (I) and formula IV have been discussed in detail above.

[0118] Attached Figure

[0119] The invention and its particularly preferred embodiments are described in more detail below. It should be emphasized that only elements necessary for understanding are shown. The same elements are shown with the same reference numerals in different figures. Furthermore, it should be emphasized that the figures are schematic and, in particular, do not represent actual dimensions or scale.

[0120] Figure 1 A schematic diagram of a general-purpose extruder 1 suitable for use in the method of the present invention is shown. The compound of formula (II) is guided through the inlet of the extruder 1, where a melting and reaction step b) is carried out at the inlet of the extruder 1 at a temperature above the melting point of XOH, particularly between 320°C and 450°C, more particularly between 330°C and 450°C, even more particularly between 360°C and 450°C, preferably between 360°C and 420°C, and more preferably between 380°C and 400°C, to produce the compound of formula (I), and the compound of formula (I) exits the extruder 1 through the outlet 3 of the extruder.

[0121] The alkali XOH can be fed into the extruder through a separate inlet (inlet 4 for KOH and / or NaOH), or directly into the extruder through inlet 2 along with the compound of formula (II). In the latter case, a premix of XOH and the compound of formula (II) is formed before entering the extruder. Preferably, XOH, especially NaOH, is introduced into the extruder 1 as a melt.

[0122] Figure 2 A cross-sectional view of an embodiment having a separate inlet for XOH is shown schematically. Figure 1More details. The extruder 1 includes a cavity 5 surrounded by a housing 6. The screw 7 of the extruder is located inside the cavity 5. The compound of formula (II) or XOH is introduced into the cavity 5 of the extruder through inlet 2 and inlet 4 for KOH and / or NaOH, respectively. Preferably, XOH, especially NaOH, is introduced into the extruder 1 as a melt. The screw 7 is rotated about its longitudinal axis by a motor 8 (indicated by arrow A). By the rotation of the screw 7, the compound of formula (II) and XOH are thoroughly mixed and conveyed along the axis from the inlet to the outlet of the extruder (indicated by arrow B). Heating elements 9, located inside or on the surface of housing 6, ensure that the compound of formula (II) and XOH are at temperatures above the melting point of XOH, particularly between 320°C and 450°C, more particularly between 330°C and 450°C, even more particularly between 360°C and 450°C, preferably between 360°C and 420°C, and more preferably between 380°C and 400°C, such that the reaction can occur and the compound of formula (I) is formed in the extruder. The formed compound of formula (I) exits the extruder through the outlet of extruder 3. Preferably, the reaction mixture is heated in a manner that yields a temperature gradient of the reaction mixture of the compound of formula (II) and XOH, such that the temperature of the reaction mixture in the section near inlets 2 and 4 is lower than the temperature of the reaction mixture in the section near outlet 3. Preferably, the extruder provides at least one degassing outlet 10 to allow gas to escape from the chamber, thereby reducing the pressure accumulated by the gas formed during the reaction. The degassing outlet preferably has a pressure control valve 11.

[0123] Figure 3 An embodiment of the method of the present invention having a first extruder 1a and a second extruder 1b is illustrated schematically, in which the compound of formula (II), particularly the compound of formula (II-A), is neutralized in step a0) in the first extruder 1a, and reaction step b) is carried out in the second extruder 1b to produce the compound of formula (I).

[0124] Compounds of formula (II), particularly those of formula (II-A), are introduced into the first extruder 1a through inlet 2a, and alkali XOH, particularly NaOH (preferably in the form of beads or granules a few millimeters in size), is introduced into the first extruder 1a through inlet 4. In the first extruder 1a, a neutralization reaction is carried out at a temperature between 100°C and 200°C, particularly between 100°C and 180°C, more particularly between 100°C and 150°C, preferably between 110°C and 130°C, to form compounds of formula (II-B). Compounds of formula (II-B) exit the first extruder 1a through outlet 3a. Compounds of formula (II-B) are transferred from outlet 3a of the first extruder to the inlet of the second extruder 1b via a connecting device 12 (e.g., a pipe), which is environmentally closed.

[0125] An alkali, alkali XOH, and especially NaOH (preferably as a melt) is introduced into the second extruder 1b through inlet 4. In the second extruder 1b, the reaction of step b) occurs at a temperature above the melting point of XOH, particularly between 320°C and 450°C, more particularly between 330°C and 450°C, even more particularly between 360°C and 450°C, preferably between 360°C and 420°C, and more preferably between 380°C and 400°C, to produce a compound of formula (I). The compound of formula (I) exits the second extruder through outlet 3b. Furthermore, Figure 3 The compound of formula (I) is shown being transferred from the outlet 3b of the second extruder to a water-containing container 13 via a connecting device 12 (e.g., a pipe), which is environmentally closed. The compound of formula (I) can be separated from the water-containing container 13. To allow gases, particularly water vapor, to escape from the first extruder 1a and the second extruder 1b, the shown... Figure 3 The extruder includes a degassing outlet 10, which preferably includes a pressure control valve.

[0126] Figure 4Further details of a preferred embodiment having a first extruder 1a and a second extruder 1b are shown schematically in cross-sectional view. Extruder 1a includes a cavity 5 surrounded by a housing 6. The screw 7 of the first extruder is located inside the cavity 5. A compound of formula (II-A), particularly (II-A2), and XOH are introduced (preferably by means of a pump 15) into the cavity 5 of the first extruder through inlet 2a and inlet 4 for KOH and / or NaOH, respectively. Preferably, XOH, preferably particularly NaOH, is introduced into the first extruder 1 in the form of beads or granules of a few millimeters (commercially available). The screw 7 is rotated about its longitudinal axis by a motor 8 (indicated by arrow A). By the rotation of the screw 7, the compound of formula (II-A) and XOH are thoroughly mixed and conveyed along the axis from the extruder inlet to the outlet (indicated by arrow B). Heating element 9 inside or on the surface of housing 6 ensures the following temperature: the compound of formula (II-A) and XOH are between 100°C and 200°C, particularly between 100°C and 180°C, more particularly between 100°C and 150°C, preferably between 110°C and 130°C, to carry out neutralization step a0), i.e., to form compound of formula (II-B).

[0127] Preferably, the mixture of compound (II-A) and XOH is heated in a manner that obtains a temperature gradient, such that the temperature of the mixture in the section near inlets 2a and 4 is lower than the temperature of the mixture in the section near outlet 3a.

[0128] The compound of formula (II-B) exits the first extruder through outlet 3a and is transferred to inlet 2b of the second extruder 1b via connecting device 12 (e.g., a pipe), which is environmentally closed. This delivery is shown in the figure to be supported by pump 15.

[0129] The second extruder 1b includes a cavity 5 surrounded by a housing 6. The screw 7 of the second extruder is located inside the cavity 5. The compound of formula (II-B) and XOH are introduced (preferably by means of a pump 15) into the cavity 5 of the second extruder through inlet 2b and inlet 4 for KOH and / or NaOH, respectively. Preferably, XOH, and especially NaOH, is introduced into the second extruder 1 as a melt. The screw 7 is rotated about its longitudinal axis by a motor 8 (indicated by arrow A). Through the rotation of the screw 7, the compound of formula (II-B) and XOH are thoroughly mixed and conveyed along the axis from the extruder inlet to the outlet (indicated by arrow B). The heating element 9 inside or on the surface of the housing 6 ensures that the compound of formula (II-B) and XOH are at a temperature above the melting point of XOH, particularly between 320°C and 450°C, more particularly between 330°C and 450°C, even more particularly between 360°C and 450°C, preferably between 360°C and 420°C, and more preferably between 380°C and 400°C, to carry out reaction step b) to obtain the compound of formula (I).

[0130] Preferably, the mixture of compound (II-B) and XOH is heated in a manner that obtains a temperature gradient, such that the temperature of the mixture in the section near inlets 3a and 4 is lower than the temperature of the mixture in the section near outlet 3b.

[0131] The compound of formula (I) exits the second extruder through outlet 3b and is transferred to a water-containing container 13 via a connecting device 12 (e.g., a pipe), which is environmentally closed. Preferably, all connecting devices 12 and pump 15 in this embodiment are heated to prevent the material inside the connecting devices from cooling and solidifying. This delivery is shown in the figure as being supported by pump 15. Adding the compound of formula (I) to the water in container 13 is preferably done by stirring using a stirring device 14 (e.g., a paddle mixer). By adding the molten mixture of the compound of formula (I) and residual XOH to the water in container 13, the compound of formula (I) is cooled to a temperature below 100°C, particularly below 60°C, and preferably below 40°C. Through this action, the compound of formula (I) forms solid particles (…). Figure 4 (not shown in the diagram), while other reaction products remain in solution. Therefore, the solid particles of the compound of formula (I) can be easily separated ( Figure 4 (not shown in the image), for example, through filtering.

[0132] In order to allow gases, especially water vapor, to escape from the first extruder 1a and the second extruder 1b, as shown Figure 4 The extruder includes a degassing outlet 10, which preferably includes a pressure control valve 11.

[0133] List of reference numerals

[0134] Example

[0135] The invention is further illustrated by the following experiments.

[0136] For the following experiments, a laboratory extruder (corresponding to...) was used. Figure 2 (Except as a premixed feed, see below).

[0137] The extruder uses three screws (length (L) = 2504 mm, outer diameter (D) = 52 mm, L / Ds = 48, screw speed ( N (As shown in Table 1), they are arranged in a parallel line. The feed rate (as shown in Table 1) is obtained from the closed funnel at the inlet of the three-screw extruder via a screw pump. Q A premixture of solid sodium hydroxide and solid sodium 2,5-dimethylbenzenesulfonate (40 / 60 weight ratio) is introduced. The extruder barrel is heated by 12 individual heating elements (210 mm) positioned along the extruder. Each element is heated individually to achieve a specific temperature (°C) to obtain a temperature gradient from the inlet (left) to the outlet (right):

[0138] In the first zone, neutralization takes place (step a0), and in the subsequent zones, melting and reaction occur (step b). A degassing outlet with a pressure control valve is located in the last third of the extruder.

[0139] The different dwell times have been tested. t r Different feed rates were used. The reaction products exiting the extruder at the extruder outlet were analyzed by GC-MS and HPLC to determine the conversion rate to sodium 2,5-dimethylphenol (sodium p-xylenol). C ).

[0140]

Claims

1. A method for preparing a compound of formula (I) from a compound of formula (II), The method includes the following steps: a) Provides compounds of formula (II) b) At a temperature above the melting point of XOH, particularly between 320°C and 450°C, more particularly between 330°C and 450°C, even more particularly between 360°C and 450°C, preferably between 360°C and 420°C, more preferably between 380°C and 400°C, the compound of formula (II) is melted and reacted with XOH in an extruder (1) to produce the compound of formula (I); Its features are, R is H or CH3, and Y is SO3H or SO3 - X + Or Cl, and X is Na or K, preferably Na.

2. The method according to claim 1, characterized in that, R=CH3.

3. The method according to claim 1 or 2, characterized in that, Y=SO3 - X + Especially SO3 - Na + .

4. The method according to claim 3, characterized in that, The compound of formula (II) is the compound of formula (II-B) prepared by step a0). a0) The compound of formula (II-A) is neutralized with XOH in an extruder at a temperature between 100°C and 20°C, particularly between 100°C and 180°C, even more particularly between 100°C and 150°C, preferably between 110°C and 130°C, to form a compound of formula (II-B). 。 5. The method according to claim 4, characterized in that, The neutralization step (a0) is carried out in the first extruder (1a), the melting reaction step (b) is carried out in the second extruder (1b), and the compound of formula (II) is transferred from the outlet (3a) of the first extruder (1a) to the inlet (2b) of the second extruder (1b).

6. The method according to any one of claims 4 or 5, characterized in that, Step a0) of neutralizing the compound of formula (II) with sodium hydroxide and / or potassium hydroxide is carried out in the presence of a molar excess of XOH, such that the molar ratio of XOH to the compound of formula (II) is >1, particularly between 1 and 2, preferably between 1 and 1.5, and more preferably between 1 and 1.

25.

7. The method according to any one of claims 4 to 6, characterized in that, Material transfer between the first extruder (1a) and the second extruder (1b) is carried out via an environmentally enclosed connecting device (12).

8. The method according to any one of claims 4 to 7, characterized in that, The compound of formula (II-a) is obtained by reacting the compound of formula (III) with sulfuric acid (H2SO4). in R is H or CH3, preferably CH3.

9. The method according to any one of the preceding claims, characterized in that, The melting reaction step b) of the compound of formula (II) with XOH is carried out in the presence of a molar excess of XOH, such that the molar ratio of XOH and / or the compound of formula (II) is >2, particularly between 2 and 4, preferably between 2 and 3, and more preferably between 2 and 2.

5.

10. The method according to any one of the preceding claims, characterized in that, The temperature of the material in the inlet (2) region of the extruder (1) is lower than the temperature of the material in the outlet (3) region of the extruder (1).

11. The method according to any one of the preceding claims, characterized in that, The extruder (1) includes at least one degassing outlet (10).

12. The method according to any one of the preceding claims, characterized in that, XOH is transferred into the extruder in the form of solid XOH or as a melt of XOH.

13. The method according to any one of the preceding claims, characterized in that, The method described is a continuous method.

14. The method according to any one of the preceding claims, characterized in that, The extruder (1) is a twin-screw or three-screw extruder.

15. The method according to any one of the preceding claims, characterized in that, The compound of formula (I), especially the compound of formula (I) together with an excess of molten XOH, is transferred after step b) to a container (13) containing water, particularly to an aqueous solution of sulfite, preferably an aqueous solution of Na2SO3.

16. A method for manufacturing a compound of formula (IV), Its features are, The method includes steps i) Prepare the compound of formula (I) by the method according to any one of claims 1-15. Next are the steps c) Acidifying the compound of formula (IV) with an acid yields the compound of formula (IV). in R is H or CH3, preferably CH3.

17. Use of extruder (1) in the manufacture of compounds of formula (I) or (IV). in R is H or CH3, preferably CH3, and X is Na or K, preferably Na.

18. An extruder (1) for manufacturing compounds of formula (I), said extruder comprising at least: -Shell (6) -The cavity (5) inside the housing (6) - The extruder screw (7) inside the cavity (5) -Inlet (2) for compounds of formula (II) - For the outlet (3) of the compound of formula (I) -A mixture of XOH and the compound of formula (II) inside the cavity (5); The characteristic feature is that R is H or CH3, and Y is SO3H or SO3. - X + Or Cl, and X is Na or K, preferably Na.

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