Organic sulfonate of amino acid ester and preparation method thereof

Abstract

The present invention relates to a method for synthesizing an organic sulfonate of an amino acid ester, comprising the following steps: (i) reacting at least one lactam having at least 3 carbon atoms in the lactam ring with at least one organic sulfonic acid in an aqueous solution, (ii) esterifying the organic sulfonic acid amino acid salt of step (i) with at least one alcohol having at least 8 carbon atoms and containing at least one hydroxyl group, (iii) optionally, removing water and / or removing excess alcohol of step (ii). The present invention also relates to an organic sulfonate of an amino acid ester of general formula (I).

Description

[0001] The present invention relates to a method for synthesizing an organic sulfonate of an amino acid ester. The present invention further relates to an organic sulfonate of an amino acid ester.

[0002] Organic sulfonates from esters of long chain alcohols and amino acids are described in the literature. Methanesulfonates of amino acid esters are synthesized from amino acids and alcohols using methanesulfonic acid at elevated temperatures (CL Penney et al., J. Org. Chem. 1985, 50, 1457-1459; AMGrubb et al., Liquid Crystals 2009, 36, 443-453; R. Ceron-Camacho et al., Molecules 2011, 16, 8733-8744).

[0003] Amino acid esters from amino acids having equal to or greater than 3 carbon atoms can be synthesized from the corresponding lactams. The synthesis includes ring opening of the lactam to the amino acid in the presence of an acid as a first step and an esterification reaction with an alcohol as a second step.

[0004] FR2977585B1 discloses a method for synthesizing C from an amino acid or its salt in the presence of water in the presence of an acid catalyst. 7 -C 36 A method for preparing α-amino acid esters of alcohols, the method starting from an amino acid or a salt thereof.

[0005] US2014 / 0039219A1 discloses a method for preparing 6-aminocaproic acid as a pharmaceutical active ingredient by using a solubility regulator to reduce the water solubility of 6-aminocaproic acid. An organic solvent for extracting a 6-aminocaproic acid intermediate from a reaction mixture is disclosed.

[0006] US Pat. No. 3,939,200 discloses novel acyl-containing amine hydrochlorides which are produced by reacting with hydrochloric acid and reacting the resulting product with an alkanolamine or a diol in an inert liquid medium while passing a stream of hydrogen chloride therethrough to convert the amino group into an acid salt.

[0007] GB934965 discloses improvements in the production of amino acid esters. It describes the production of amino acid esters from lactams by using an esterifying alcohol in the presence of hydrogen chloride or hydrogen bromide and a significant amount of water and subsequently removing the water with a solvent that can form an azeotrope with water.

[0008] US20160068471 discloses ionic amino acid esters obtained by reacting an unprotected α-amino acid with a fatty alcohol in the presence of an organic acid such as a carboxylate, a mesylate, a tosylate or a sulfonate.

[0009] WO2015172158 discloses salts of ethanesulfonic acid α- and higher amino acid esters.

[0010] JIN, S. Chemistry of Materials, 2011, Vol. 23, pp. 2689-2692 and supporting information disclose salts of toluenesulfonic acid with α- and higher amino acid esters.

[0011] There is a continuing need for an improved process for preparing amino acid esters and salts thereof, which allows the preparation of amino acid esters and salts thereof, in particular esters of alcohols having a boiling point significantly above 100° C., in high yields with fast reaction times, without handling of organic solvents and without handling of gaseous corrosive acids. There is also a need for a process which allows the quantitative reaction of amino acids and amino acid precursors such as lactams with alcohols which have a low water solubility and can therefore only be dispersed in water to form amino acid esters and salts thereof.

[0012] There is a continuing need for amino acid ester salts with improved stability.The improved stability of amino acid ester salts in alkaline aqueous solutions allows the incorporation of amino acid ester salts into improved detergent formulations for fabric and home care applications such as hard surface cleaning.

[0013] The object of the present invention is to provide a method which meets the above-mentioned objectives and needs.

[0014] This object is achieved by the present invention as described hereinafter and as reflected in the claims.

[0015] Throughout the specification and the claims that follow, unless the context requires otherwise, the word "comprise" and variations such as "include" and "comprising" will be understood to mean the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of any other integer or step or group of integers or steps. When used herein, the term "comprise" may be replaced with the term "contains" or "includes", or sometimes when used herein, may be replaced with the term "having".

[0016] When used herein, "consisting of excludes any element, step or ingredient not specified in the claimed element. When used herein, "consisting essentially of does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim.

[0017] In each instance herein, any of the terms "comprising," "consisting essentially of," and "consisting of may be replaced with either of the other two terms.

[0018] Generally speaking, the term "obtainable by..." as used herein means that the corresponding product does not necessarily have to be produced (i.e., obtained) by the corresponding method or process described in the corresponding specific context, but also includes a product that exhibits all the characteristics of a product produced (obtained) by the corresponding method or process, wherein the product is not actually produced (obtained) by the method or process. However, the term "obtainable by..." also includes the more restrictive term "obtained by...", i.e., a product actually produced (obtained) by the method or process described in the corresponding specific context.

[0019] When any definition requiring a compound or a substituent of a compound to consist of "at least a certain number of carbon atoms" is used herein, the number of carbon atoms refers to the total number of carbon atoms in the compound or the substituent of the compound. For example, for a substituent disclosed as "an ether alkyl group having at least 8 carbon atoms containing an oxyalkylene group", the total number of at least 8 carbon atoms needs to be the sum of the number of carbon atoms of the alkyl moiety and the number of carbon atoms of the oxyalkylene moiety.

[0020] The present invention relates to a method for synthesizing an organic sulfonate of an amino acid ester, comprising the steps of: (i) reacting at least one lactam having at least 3 carbon atoms in the lactam ring with at least one

[0021] Organic sulfonic acid reacts in aqueous solution.

[0022] (ii) esterifying the reaction product of step (i) with at least one alcohol having at least 8 carbon atoms and comprising at least one hydroxyl group,

[0023] (iii) optionally, removing water and / or removing excess alcohol from step (ii).

[0024] Lactams are cyclic amides, starting with α-lactam (3 ring atoms), followed by β-lactam (4 ring atoms), γ-lactam (5 ring atoms), and so on. When hydrolyzed, lactams form the corresponding α-, β-, γ-amino acids. All lactams having at least 3 carbon atoms in the lactam ring can be used in the method for synthesizing organic sulfonates. In one embodiment of the present invention, lactams having 4-12 carbon atoms in the lactam ring are used. In another embodiment of the present invention, lactams having 5-7 carbon atoms in the lactam ring are used. In another embodiment, lactams having 6 carbon atoms in the lactam ring, ε-lactams, are used.

[0025] The reaction of the lactam ring is carried out by reacting the at least one lactam with at least one organic sulfonic acid in the presence of water. In one embodiment of the invention, the reaction of the at least one lactam with at least one organic sulfonic acid in the presence of water is carried out as a separate step (i) of the process. In another embodiment, the reaction of the at least one lactam with at least one organic sulfonic acid in the presence of water is carried out in combination with step (ii) - the reaction with at least one alcohol having at least 8 carbon atoms containing at least one hydroxyl group.

[0026] The at least one organic sulfonic acid is selected from the group consisting of alkyl sulfonic acids, alkylaryl sulfonic acids, alkene sulfonic acids, camphor sulfonic acid and mixtures thereof. In one embodiment of the present invention, the organic sulfonic acid has the general formula RS(=O) 2 -OH, wherein R is alkyl, alkaryl, alkenyl or aryl. In another embodiment, the organic sulfonic acid has the general formula RS(=O) 2 -OH, wherein R is an alkyl or alkaryl group. In another embodiment of the present invention, the organic sulfonic acid has the general formula RS(=O) 2 -OH, where R is a branched or linear C 1 -C 36 In another embodiment, the organic sulfonic acid has the general formula RS(=O) 2 -OH, where R is a branched or linear C 4 -C 12 In another embodiment, the organic sulfonic acid is methanesulfonic acid.

[0027] In another embodiment, the organic sulfonic acid is an alkylbenzene sulfonic acid. In another embodiment, the organic sulfonic acid is C 4 -C 20 In another embodiment, the organic sulfonic acid is selected from 2,6-dimethylbenzenesulfonic acid, 2,5-dimethylbenzenesulfonic acid, 2,4-dimethylbenzenesulfonic acid and mixtures thereof. In another embodiment, the organic sulfonic acid is 4-dodecylbenzenesulfonic acid. In another embodiment, the organic sulfonic acid is selected from isopropylbenzenesulfonic acid, ethylbenzenesulfonic acid and naphthalenesulfonic acid. In another embodiment, the organic sulfonic acid is selected from dodecylbenzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid and methanesulfonic acid. In yet another embodiment, the organic sulfonic acid is p-toluenesulfonic acid.

[0028] In one embodiment of the invention, the lactam is selected from lactams having 5 carbon atoms in the lactam ring and lactams having 6 carbon atoms in the lactam ring and the organic sulfonic acid is selected from methanesulfonic acid and alkylbenzenesulfonic acid. In another embodiment of the invention, the lactam has 5 carbon atoms in the lactam ring and the organic sulfonic acid is methanesulfonic acid. In another embodiment, the lactam has 5 carbon atoms in the lactam ring and the organic sulfonic acid is alkylbenzenesulfonic acid. In another embodiment of the invention, the lactam has 6 carbon atoms in the lactam ring and the organic sulfonic acid is methanesulfonic acid. In another embodiment, the lactam has 6 carbon atoms in the lactam ring and the organic sulfonic acid is alkylbenzenesulfonic acid.

[0029] In one embodiment, the lactam is dissolved in water or dispersed in the aqueous phase. The typical concentration of the lactam in water is in the range of 50-99% by weight based on the total weight of the lactam and water. In one embodiment of the invention, the concentration of the lactam in water is in the range of 55-90% by weight based on the total weight of the lactam and water. In another embodiment, the concentration of the lactam in water is in the range of 65-80% by weight based on the total weight of the lactam and water. At least one organic sulfonic acid is used as a liquid or dissolved in water at a temperature above its melting point. The typical concentration of the organic sulfonic acid dissolved in water is in the range of 50-95% by weight based on the total weight of the solution. In one embodiment of the invention, the concentration of the organic sulfonic acid dissolved in water is in the range of 60-80% by weight based on the total weight of the solution. In one embodiment of the invention, the total amount of organic sulfonic acid is added to the aqueous solution of the at least one lactam at the beginning of the reaction. In another embodiment, the at least one organic sulfonic acid is added dropwise to the at least one lactam that is already an aqueous solution or dispersed in water over a duration of 0.1-10 hours.

[0030] The molar ratio of the organic sulfonic acid to the lactam is in the range of 90-200 mol%. In another embodiment of the present invention, the molar ratio of the organic sulfonic acid to the lactam is in the range of 100-150 mol%. In another embodiment, the molar ratio of the organic sulfonic acid to the lactam is in the range of 100-125 mol%. In another embodiment, the molar ratio of the organic sulfonic acid to the lactam is in the range of 110-120 mol%.

[0031] In all embodiments of the present invention, no additional solvent other than water is present in step (i) of the process.

[0032] The reaction of the at least one lactam with the at least one organic sulfonic acid is carried out at a temperature of 50-150°C. In one embodiment of the invention, the reaction is carried out at a temperature of 80-140°C. In another embodiment, the reaction is carried out at a temperature of 90-130°C. In one embodiment of the invention, the temperature is kept constant for the duration of the reaction. In another embodiment, the temperature varies within a temperature range for the duration of the reaction. The reaction of the at least one lactam with the at least one organic sulfonic acid is carried out for a duration of 0.1-10 hours. In another embodiment of the invention, the duration is 1-7 hours. In another embodiment, the duration is 2-5 hours. In one embodiment of the invention, the reaction of the at least one lactam with the at least one organic acid is carried out at atmospheric pressure. In one embodiment, a protective atmosphere such as nitrogen or argon is used to carry out the reaction. In another embodiment, the reaction of the at least one lactam with the at least one organic sulfonic acid is carried out at a temperature of 50-150°C at atmospheric pressure for a duration of 0.1-10 hours. In another embodiment of the invention, the reaction of the at least one lactam with the at least one organic sulfonic acid is carried out at a temperature of 90-130°C at atmospheric pressure for 3 hours.

[0033] The esterification is carried out by reacting the organic sulfonic acid amino acid salt formed by the reaction of step (i) with at least one alcohol having at least 8 carbon atoms containing at least one hydroxyl group. In one embodiment of the present invention, the esterification reaction of the organic sulfonic acid amino acid salt formed by the reaction of step (i) with at least one alcohol having at least 8 carbon atoms containing at least one hydroxyl group is carried out as a separate step (ii) of the process. In another embodiment, the esterification reaction step (ii) is carried out in parallel with step (i) - the hydrolysis reaction of the process, so that steps (i) and (ii) of the process are carried out in a single step.

[0034] If step (ii) is carried out as a separate step after step (i) of the process, the reaction of step (i) is carried out until the hydrolysis of the lactam ring is complete. Complete is to be understood in the sense that no further hydrolysis can occur, either because all lactam rings are hydrolyzed or because no further hydrolysis is possible given the chemical nature of the reaction pair and its amount.

[0035] After complete hydrolysis, at least one alcohol having at least 8 carbon atoms and containing at least one hydroxyl group is added to the reaction mixture. The alcohol is added without additional solvent or dissolved in water. In one embodiment of the invention, the alcohol is selected from monohydric alcohols, diols, polyols, alkoxylated monohydric alcohols, alkoxylated diols and alkoxylated polyols having at least 8 carbon atoms. In another embodiment of the invention, at least one linear or branched C 8 -C 36Alcohols. In one embodiment, the alcohols are alkoxylated with ethylene oxide and / or propylene oxide and / or butylene oxide. The alkoxylation is carried out with only one alkylene oxide or with more than one alkylene oxide. If more than one alkylene oxide is used, the resulting alkoxylated alcohols contain randomly distributed alkylene oxide units or one alkylene oxide block followed by another alkylene oxide block. In one embodiment of the invention, alcohols alkoxylated with only a single alkylene oxide are used. In another embodiment, alcohols alkoxylated with a first alkylene oxide and subsequently with a second alkylene oxide are used, thereby forming a block structure of different alkylene oxide blocks. In yet another embodiment, alkoxylated 2-propylheptanol is used.

[0036] In another embodiment, at least one selected from unalkoxylated linear C 8 -C 36 Alcohol, unalkoxylated branched C 8 -C 36 Alcohol, alkoxylated linear C 8 -C 36 Alcohols and alkoxylated branched C 8 -C 36 In another embodiment, the alcohol used in step (ii) is selected from the group consisting of unalkoxylated or alkoxylated linear or branched C 8 -C 36 In another embodiment, at least one C 12 -C 22 In another embodiment, fatty alcohol is used. 16 and C 18 In another embodiment, C 18 and C 22 In another embodiment, a linear or branched C 8 -C 10 Monohydric alcohol. In another embodiment, 2-propylheptanol or 2-ethylhexanol is used. In yet another embodiment, 2-ethylhexanol is used.

[0037] In another embodiment of the invention, at least one phenoxyalkanol is used. In another embodiment, phenoxyethanol is used.

[0038] The molar ratio of the organic sulfonic acid amino acid salt of step (i) is in the range of 50-125 mol% when a monohydric alcohol is used in step (ii). The molar ratio of the organic sulfonic acid amino acid salt of step (i) to the hydroxyl group is in the range of 10-125 mol% when a diol or a polyol is used in step (ii). In another embodiment of the present invention, the molar ratio of the organic sulfonic acid amino acid salt of step (i) to the hydroxyl group of the diol or polyol of step (ii) is in the range of 25-100 mol%. In another embodiment, the molar ratio of the organic sulfonic acid amino acid salt of step (i) to the hydroxyl group of the alcohol of step (ii) is in the range of 100-125 mol%.

[0039] The esterification reaction of step (ii) is carried out at a temperature in the range of 80-200°C. In another embodiment of the present invention, the esterification reaction is carried out at a temperature in the range of 120-140°C. In one embodiment of the present invention, the temperature is kept constant during the reaction duration. In another embodiment, the temperature is changed within the temperature range during the reaction duration. The duration of the esterification reaction of step (ii) is 1-30 hours. In another embodiment of the present invention, the duration of the esterification reaction is 2-5 hours. In one embodiment, a vacuum in the range of 0.1-800 mbar is applied. In another embodiment, a vacuum in the range of 1-500 mbar is applied. In another embodiment, a vacuum in the range of 10-100 mbar is applied.

[0040] Step (i) and step (ii) can be carried out in a single step. At this time, at least one lactam, at least one organic sulfonic acid and at least one alcohol with at least 8 carbon atoms containing at least one hydroxyl group are mixed to form an aqueous solution or an aqueous dispersion. The lactam is dissolved in water or dispersed in an aqueous phase. In one embodiment of the invention, the concentration of the lactam in water is in the range of 50-99 weight % based on the total weight of the lactam and water. In one embodiment of the invention, the concentration of the lactam in water is in the range of 55-90 weight % based on the total weight of the lactam and water. At least one organic sulfonic acid is used as a liquid or dissolved in water at a temperature above its melting point. The typical concentration of the organic sulfonic acid dissolved in water is in the range of 50-95 weight % based on the total weight of the solution. In one embodiment of the invention, the entire amount of organic sulfonic acid is added to the aqueous solution of the at least one lactam and the at least one alcohol containing at least one hydroxyl group at the beginning of the reaction. In another embodiment, the at least one organic sulfonic acid is added dropwise to the at least one lactam and the at least one alcohol that are already in an aqueous solution or dispersed in water over a duration of 0.1-10 hours.

[0041] The combined reaction of step (i) and step (ii) is carried out at a temperature in the range of 80-200°C. In another embodiment of the present invention, the esterification reaction is carried out at a temperature in the range of 120-140°C. In one embodiment of the present invention, the temperature remains constant during the reaction duration. In another embodiment, the temperature varies within the temperature range during the reaction duration. The duration of the esterification reaction of step (ii) is 1-30 hours. In another embodiment of the present invention, the duration of the esterification reaction is 2-5 hours. In one embodiment, a vacuum in the range of 0.1-800 mbar is applied. In another embodiment, a vacuum in the range of 1-500 mbar is applied. In another embodiment, a vacuum in the range of 10-100 mbar is applied.

[0042] In all embodiments where step (i) and step (ii) are performed separately and in all embodiments where step (i) and step (ii) are performed in one single step, no additional organic solvent other than the alcohol or alcohol mixture used to esterify the organic sulfonic acid amino acid salt is present. Water is not an organic solvent.

[0043] In another embodiment, when steps (i) and (ii) are carried out in a single step, the process comprises reacting at least one organic sulfonic acid, at least one lactam having at least 3 carbon atoms in the lactam ring and at least one linear or branched C 8 -C 36 The alcohol mixture is reacted at a temperature of 80-200°C for 1-10 hours.

[0044] Water and / or excess alcohol can be removed after step (ii) or after the combined steps (i) and (ii). The removal of water and alcohol can be carried out by all techniques known in the art, for example by applying a vacuum.

[0045] The present invention also relates to organic sulfonates of amino acid esters of formula (I):

[0046]

[0047] wherein R1 is selected from the group consisting of methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene and decylene,

[0048] Where R2 is H or C 1 -C 12 alkyl,

[0049] wherein R3 is a linear or branched, unmodified or modified with one or more hydroxyl groups, alkyl radical having at least 8 carbon atoms, or a linear or branched, unmodified or modified with one or more hydroxyl groups, ether alkyl radical having at least 8 carbon atoms,

[0050] Wherein R4 is selected from C 3 -C 30 Alkyl, phenyl, phenoxyalkyl, alkylaryl except tolyl, C 3 -C 30 alkenyl, camphoryl and mixtures thereof.

[0051] In one embodiment of the present invention, R1 is selected from propylene and butylene.

[0052] In one embodiment of the present invention, R2 is selected from the group consisting of hydrogen, methyl and ethyl. In another embodiment, R2 is hydrogen.

[0053] In one embodiment of the present invention, R3 is a linear or branched C 8 -C 36 In another embodiment, R3 is a linear or branched C 8 -C 36 Alkyl. In another embodiment, R3 is an ether alkyl group with at least 8 carbon atoms comprising an oxyalkylene group terminated with a linear or branched alkyl group. In one embodiment, R3 is an ether alkyl group with at least 8 carbon atoms comprising an oxyethylene group and / or an oxypropylene group and / or an oxybutylene group terminated with a linear or branched alkyl group. The alkoxy group is selected from only one type of alkoxy group or from more than one type of alkoxy group. If more than one type of alkoxy group is present, the resulting alkoxylate contains randomly distributed alkoxy groups or one type of alkoxy block followed by another type of alkoxy block. In one embodiment of the present invention, an ether alkyl group having only one type of alkoxy group is used. In another embodiment, an ether alkyl group having a first type of alkoxy group followed by a second type of alkoxy group is used to form a block structure of different alkoxy groups.

[0054] In one embodiment, R3 is a linear or branched C 10 -C 36 An ether alkyl group is an ether alkyl group terminated by an alkanol group and having a single oxyalkylene group. In yet another embodiment, R3 is an ether alkyl group comprising an alkoxy block followed by a 2-propylheptyl group.

[0055] In another embodiment, R3 is selected from C 12 -C 22 In another embodiment, R3 is selected from C 16 -C 18 In another embodiment, R3 is selected from C 18 -C 22 In another embodiment, R3 is selected from a linear or branched C 8 -C 10In another embodiment, R3 is 2-propylheptyl or 2-ethylhexyl. In yet another embodiment, R3 is 2-ethylhexyl.

[0056] In one embodiment of the present invention, R4 is a branched or linear C 4 -C 20 In another embodiment, R4 is a branched or linear C 4 -C 12 In another embodiment, R4 is (7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methyl.

[0057] In one embodiment of the present invention, R4 is a linear or branched alkenyl group having at least one double bond in the alkenyl chain. In another embodiment, R4 is a linear or branched C 6 -C 30 In another embodiment, the linear or branched alkenyl of R4 is a β- or higher olefinic C 6 -C 30 Alkenyl.

[0058] In another embodiment, R4 is an alkylbenzyl group other than toluoyl. 4 -C 20 In another embodiment, R4 is selected from 2,6-dimethylbenzyl, 2,5-dimethylbenzyl, 2,4-dimethylbenzyl and mixtures thereof. In another embodiment, R4 is 4-dodecylbenzyl. In another embodiment, R4 is selected from isopropylbenzyl, ethylbenzyl and naphthyl. In another embodiment, R4 is dodecylbenzyl.

[0059] In another embodiment, R4 is a substituted phenyl of formula (II):

[0060]

[0061] wherein the bond marked with an * represents the bond connecting the group to the sulfur atom, and

[0062] wherein R5, R6, R7, R8 and R9 are each independently selected from hydrogen and linear and branched C 1 -C 20 In another embodiment, R4 is a substituted phenyl of formula (II), wherein one of R5, R6, R7, R8 and R9 is a linear or branched C 11 alkyl and the remaining substituents are hydrogen.

[0063] One embodiment of the present invention relates to an organic sulfonate of an amino acid ester of formula (I), wherein R1 is propylene and butylene, R2 is hydrogen and R3 is a linear or branched C 8 -C 36 In another embodiment, R1 is propylene and butylene, R2 is hydrogen, and R3 is a linear or branched C 8 -C 36 In another embodiment, R1 is butylene, R2 is hydrogen, R3 is 2-propylheptyl or 2-ethylhexyl and R4 is alkylbenzyl excluding toluoyl. In another embodiment, R1 is butylene, R2 is hydrogen, R3 is 2-propylheptyl and R4 is dodecylbenzyl. In another embodiment, R1 is butylene, R2 is hydrogen, R3 is 2-propylheptyl and R4 is xylene. In another embodiment, R1 is butylene, R2 is hydrogen, R3 is 2-propylheptyl and R4 is dodecylbenzyl. In another embodiment, R1 is butylene, R2 is hydrogen, R3 is 2-ethylhexyl and R4 is dodecylbenzyl. In another embodiment, R1 is butylene, R2 is hydrogen, R3 is 2-ethylhexyl and R4 is dodecylbenzyl. In another embodiment, R1 is butylene, R2 is hydrogen, R3 is 2-ethylhexyl and R4 is xylene. In one embodiment of the present invention, in the organic sulfonate of the amino acid ester of formula (I), R1 is butylene, R2 is H, R3 is phenoxyethyl and R4 is dodecylbenzyl. Example

[0064] method

[0065] Measured in MeOD with a Bruker Avance 400 MHz spectrometer 1 H NMR.

[0066] Embodiment 1:

[0067] In a 4-necked vessel with a thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 141.45 g of caprolactam (80 wt % aqueous solution) was placed and heated to 70° C. At this temperature, 140.04 g of methanesulfonic acid (70 wt % aqueous solution) was added within 20 minutes. The temperature was raised to 118° C. and the mixture was stirred for 3 hours. The mixture was cooled to 90° C. and 156.27 g of 2-ethylhexanol was added within 20 minutes. The reaction mixture was heated to 120° C. and a vacuum (950-850 mbar) was applied to remove water. After 3 hours at 120° C., the vacuum was reduced to 20 mbar. The reaction mixture was stirred at 20 mbar and 130° C. for 2.5 hours. 332.0 g of a light brown solid was obtained. 1 H-NMR showed complete conversion to 6-aminohexanoic acid 2-ethylhexyl ester methanesulfonate.

[0068] Embodiment 2:

[0069] In a 4-necked vessel with a thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 141.45 g of caprolactam (80 wt. % aqueous solution) and 156.27 g of 2-ethylhexanol were placed and heated to 40° C. At this temperature, 140.04 g of methanesulfonic acid (70 wt. % aqueous solution) were added within 20 minutes. The temperature was raised to 110° C. and the mixture was stirred at 110° C. for 3 hours. A vacuum was applied and reduced to 20 mbar while the temperature was raised to 140° C. The reaction mixture was stirred at 20 mbar and 140° C. for 2.5 hours. 330.0 g of a light brown solid was obtained. 1 H-NMR showed complete conversion to 6-aminohexanoic acid 2-ethylhexyl ester methanesulfonate.

[0070] Embodiment 3:

[0071] In a 4-necked container equipped with a thermometer, a reflux condenser, a nitrogen inlet, a dropping funnel and a stirrer, 19.3 g of caprolactam (80 wt % aqueous solution) and 38.7 g of C 16 / C 18 Fatty alcohol (hydroxyl value 217.4 mg KOH / g) was added and heated to 70°C. At this temperature, 27.3 g methanesulfonic acid (70% by weight in water) was added within 20 minutes. The temperature was raised to 120°C and the homogeneous mixture was stirred at 120°C for 3 hours. A vacuum was applied and reduced to 20 mbar while the temperature was raised to 138°C. The reaction mixture was stirred at 20 mbar and 140°C for 8 hours. 65.5 g of a light brown solid was obtained. 1 H-NMR showed complete conversion to 6-aminohexanoic acid C 16 / C 18 Fatty alcohol ester mesylate.

[0072] Embodiment 4:

[0073] In a 4-necked container equipped with a thermometer, a reflux condenser, a nitrogen inlet, a dropping funnel and a stirrer, 19.3 g of caprolactam (80 wt % aqueous solution) and 44.6 g of C 18 / C 22 Fatty alcohol (hydroxyl value 188.6 mg KOH / g) was added and heated to 70°C. At this temperature, 27.3 g methanesulfonic acid (70% by weight in water) was added within 20 minutes. The temperature was raised to 120°C and the homogeneous mixture was stirred at 126°C for 3 hours. A vacuum was applied and reduced to 20 mbar while the temperature was raised to 138°C. The reaction mixture was stirred at 20 mbar and 140°C for 8 hours. 71.4 g of a light brown solid was obtained. 1 H-NMR showed complete conversion to 6-aminohexanoic acid C 18 / C 22 Fatty alcohol ester mesylate.

[0074] Embodiment 5:

[0075] In a 4-necked vessel with a thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 21.3 g of 2-pyrrolidone and 39.1 g of 2-ethylhexanol were placed and heated to 50° C. At this temperature, 35.0 g of methanesulfonic acid (70% by weight in water) were added within 20 minutes. The temperature was raised to 104° C. and the mixture was stirred at 104-110° C. for 3 hours. A vacuum was applied and reduced to 20 mbar while the temperature was raised to 135° C. The reaction mixture was stirred at 20 mbar and 135° C. for 2.5 hours. 75.0 g of a light brown solid was obtained. 1 H-NMR showed complete conversion to 4-aminobutyric acid 2-ethylhexyl ester methanesulfonate.

[0076] Embodiment 6:

[0077] In a 4-necked vessel with a thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 24.7 g of 2-piperidone and 39.6 g of 2-ethylhexanol were placed and heated to 50° C. At this temperature, 35.0 g of methanesulfonic acid (70% by weight in water) were added within 20 minutes. The temperature was raised to 104° C. and the mixture was stirred at 104-110° C. for 5.5 hours. A vacuum was applied and reduced to 20 mbar while the temperature was raised to 135° C. The reaction mixture was stirred at 20 mbar and 135° C. for 2.5 hours. 81.0 g of a light brown solid was obtained. In MeOD 1 H-NMR showed complete conversion to 4-aminopentanoic acid 2-ethylhexyl ester methanesulfonate.

[0078] Embodiment 7:

[0079] In a 4-necked vessel with a thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 35.4 g of caprolactam (80 wt. % aqueous solution) and 35.8 g of 2-ethylhexanol were placed and heated to 45° C. At this temperature, 48.5 g of p-toluenesulfonic acid were added in portions over 20 minutes. The temperature was raised to 110° C. and the mixture was stirred at 110° C. for 4 hours. A vacuum was applied and reduced to 20 mbar while the temperature was raised to 140° C. The reaction mixture was stirred at 20 mbar and 140° C. for 5 hours. 95.0 g of a light brown solid was obtained. 1 H-NMR showed 88% conversion to 6-aminohexanoic acid 2-ethylhexyl ester p-toluenesulfonate.

[0080] Embodiment 8:

[0081] In a 4-necked vessel with thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 21.3 g of caprolactam (80% by weight aqueous solution) and 43.6 g of 2-propylheptanol ethoxylated with 3 mol of ethylene oxide were placed and heated to 45° C. At this temperature, 52.6 g of 4-dodecylbenzenesulfonic acid (isomer mixture) were added within 20 minutes. The temperature was raised to 133° C. and the mixture was stirred at 133° C. for 4 hours. A vacuum was applied and reduced to 5 mbar while the temperature was raised to 140° C. The reaction mixture was stirred at 5 mbar and 140° C. for 5 hours. 99.0 g of a brown oil were obtained. In MeOD 1 H-NMR showed 82% conversion to 4-dodecylbenzenesulfonic acid (isomer mixture) salt of 6-aminohexanoic acid triethylene glycol 2-propylheptyl ether ester.

[0082] Embodiment 9:

[0083] In a 4-necked vessel with thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 21.2 g of caprolactam (80% aqueous solution) and 26.1 g of 2-propylheptanol were placed and heated to 40° C. At this temperature, 52.6 g of 4-dodecylbenzenesulfonic acid (mixture of isomers) were added within 20 minutes. The temperature was raised to 110° C. and the mixture was stirred at 110° C. for 4 hours. The mixture was heated to 130° C. and the water formed was evaporated off for 5 hours. A vacuum was applied and reduced to 4 mbar while the temperature was raised to 140° C. The reaction mixture was stirred at 4 mbar and 140° C. for 4 hours. 77.0 g of a brown oil was obtained. In MeOD 1 H-NMR showed 81% conversion to 4-dodecylbenzenesulfonic acid (isomer mixture) salt of 2-propylheptyl 6-aminohexanoate.

[0084] Embodiment 10:

[0085] In a 4-necked container with a thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 21.2 g of caprolactam (80 wt % aqueous solution) and 5.0 g of water were placed and heated to 70° C. At this temperature, 52.6 g of 4-dodecylbenzenesulfonic acid (mixture of isomers) were added within 20 minutes. The temperature was raised to 118° C. and the mixture was stirred for 4 hours. The mixture was cooled to 90° C. and 21.5 g of 2-ethylhexanol was added within 20 minutes. The reaction mixture was heated to 120° C. and a vacuum (950-850 mbar) was applied to remove water. After 3 hours at 120° C., the vacuum was reduced to 20 mbar. The reaction mixture was stirred at 20 mbar and 130° C. for 2.5 hours. 77.4 g of a light brown oil was obtained. 1 H-NMR showed 73% conversion to 4-dodecylbenzenesulfonic acid (isomer mixture) salt of 2-ethylhexyl 6-aminohexanoate.

[0086] Embodiment 11:

[0087] In a 4-necked vessel equipped with a thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 21.5 g of 2-ethylhexanol and 19.7 g of 6-aminocaproic acid were placed and heated to 50° C. To this mixture was added 52.6 g of 4-dodecylbenzenesulfonic acid (mixture of isomers) over 10 minutes. The reaction mixture was heated to 133° C. and stirred at 133° C. for 4 hours, and the water formed was evaporated. Excess 2-ethylhexanol and volatile compounds were removed under vacuum (7 mbar) at elevated temperature (140° C.) to give 80.7 g of a light brown oil. In MeOD 1 H-NMR showed complete conversion to 4-dodecylbenzenesulfonate of 2-ethylhexyl 6-aminohexanoate.

[0088] Embodiment 12:

[0089] In a 4-necked vessel with thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 43.6 g of 2-propylheptanol ethoxylated with 3 mol of ethylene oxide and 19.7 g of 6-aminocaproic acid were placed and heated to 90° C. To this mixture was added 52.6 g of 4-dodecylbenzenesulfonic acid (isomer mixture) over 10 minutes. The reaction mixture was heated to 135° C. and stirred at 135° C. for 4 hours. A vacuum (5 mbar) was applied and the reaction mixture was stirred at 140° C. for a further 10 hours. 102.1 g of a light brown solid were obtained. In MeOD 1 H-NMR showed complete conversion to 4-dodecylbenzenesulfonic acid (isomer mixture) salt of 6-aminohexanoic acid triethylene glycol 2-propylheptyl ether ester.

[0090] Embodiment 13:

[0091] In a 4-necked vessel with a thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 42.4 g of caprolactam (80% aqueous solution), 41.4 g of phenoxyethanol and 18.5 g of water were placed and heated to 40° C. At this temperature, 99.9 g of 4-dodecylbenzenesulfonic acid (mixture of isomers) were added within 10 minutes. The mixture was heated to reflux (about 100° C.) and stirred at reflux for 4 hours. A vacuum was applied and reduced to 350 mbar while the temperature was raised to 130° C. The reaction mixture was stirred at 350 mbar and 130° C. for 5 hours. In order to remove residual water, the vacuum was reduced to 10 mbar and the mixture was stirred at 130° C. and 10 mbar for 2 hours. 160.0 g of a brown oil was obtained. 1 H-NMR showed 99.5% conversion to 4-dodecylbenzenesulfonic acid (isomer mixture) salt of 6-aminohexanoic acid phenoxyethanol ester.

[0092] Embodiment 14:

[0093] In a 4-necked vessel with a thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 62.2 g of caprolactam (80% aqueous solution) and 67.5 g of phenoxyethanol were placed and heated to 40° C. At this temperature, 61.6 g of methanesulfonic acid (70% aqueous solution) were added within 10 minutes. The mixture was heated to reflux (about 100° C.) and stirred at reflux for 4 hours. A vacuum was applied and gradually reduced to 10 mbar while the temperature was raised to 130° C. The reaction mixture was stirred at 10 mbar and 130° C. for 10 hours. 149.0 g of a brown solid was obtained. In MeOD 1 H-NMR showed 97.2% conversion to the methanesulfonate salt of 6-aminohexanoic acid phenoxyethanol ester.

[0094] Comparative Example 1:

[0095] In a 4-necked vessel with thermometer, reflux condenser, nitrogen inlet, dropping funnel and stirrer, 56.58 g of caprolactam (80% in water) and 44.47 g of isobutanol were placed and heated to 46° C. At this temperature, 56.01 g of methanesulfonic acid were added over 20 minutes. The temperature was raised to 63° C. After complete addition of the methanesulfonic acid, the temperature was raised to 104° C. (reflux) and the mixture was stirred at 105° C. for 11 hours. A vacuum was applied down to 20 mbar to remove excess isobutanol and stirred for 1 hour. The mixture was stirred at 40° C. for 1 hour. The mixture was stirred at 3 ...30° C. for 1 hour. The mixture was stirred at 30° C. for 1 hour. The mixture was stirred at 30° C. for 1 hour. The mixture was stirred at 30° C. for 1 hour. 1 H-NMR showed a 45:55 mixture of 6-aminohexanoic acid isobutyl ester methanesulfonate and unesterified 6-aminohexanoic acid methanesulfonate.

[0096] Stability in alkaline solutions

[0097] To determine the stability under alkaline conditions, 50 wt % of the organic sulfonate of the amino acid ester was dissolved in water and the pH was adjusted to pH 8.5 with sodium hydroxide. The aqueous solution or emulsion was stored at room temperature and 40°C for 7 days. The CH 2 The integral of -O-CO- (in MeOD 1 H-NMR, ∼4.2 ppm). The stability of the organic sulfonate salts of amino acid esters was measured by measuring the CH 2 The integral of -O-CO- (in MeOD 1 H-NMR) shows. Calculate the residual amount of ester bond:

[0098]

[0099] Table 1. Residual ester bonds after storage [%], calculated from the 1 H-NMR calculations

[0100]

[0101] *Comparative Examples 2-5 were prepared similarly to the procedure disclosed in Example 11.

[0102] Use as an additive in detergents

[0103] Industrial stain swatches of blue knitted cotton containing bacon grease were purchased from Warwick Equest Ltd. The stain was washed for 30 minutes at room temperature in a bottle type stain removal tester (manufactured by SDL Atlas) using 500 mL of washing solution per tank, 20 metal balls and ballast fabric. The washing solution contained 5000 ppm of detergent composition DC1 (Table 2). The water hardness was 2.5 mM (Ca 2 + Mg 2+ The additives were added to the wash solution in each tank separately in the amounts detailed below. After addition, the pH was readjusted to the pH of the wash solution without the additive.

[0104] Standard colorimetric measurements were used to obtain the L*, a* and b* values ​​for each stain before and after washing. The stain grade was calculated from the L*, a* and b* values ​​as the color difference ΔE between the stain and the untreated fabric (calculated according to DIN EN ISO 11664-4).

[0105] The decontamination of the sample is calculated as follows:

[0106]

[0107] ΔE 初始 =Stain level before washing

[0108] ΔE 洗后 = Post-wash stain level

[0109] The stain level corresponds to the amount of grease on the fabric. The stain level of the fabric before washing (ΔE 初始 ) is high, stain removal during washing and the stain level after washing is smaller (ΔE 洗后 ). The better the decontamination, the greater the ΔE 洗后 The lower the value and the more ΔE 初始 Therefore, the stain removal index value increases with better washing performance.

[0110] Table 2: Detergent composition DC1

[0111]

[0112] Table 3: Washing test

[0113]

Claims

1. A method for synthesizing an organic sulfonate of an amino acid ester, comprising the steps of: (i) reacting at least one lactam having at least 3 carbon atoms in the lactam ring with at least one organic sulfonic acid in aqueous solution, (ii) esterifying the reaction product of step (i) with at least one alcohol having at least 8 carbon atoms and comprising at least one hydroxyl group, (iii) optionally, removing water and / or removing excess alcohol from step (ii); The molar ratio of the organic sulfonic acid to the lactam is in the range of 100-125 mol %, The molar ratio of the organic sulfonic acid amino acid salt to the hydroxyl group in step (i) is 2.0:1 when the monohydric alcohol is used in step (ii). In the case of The molar ratio of the organic sulfonic acid amino acid salt to the hydroxyl group in step (i) is in the range of 10-125 mol % in the case where a polyol is used in step (ii).

2. The process according to claim 1, wherein the molar ratio of the organic sulfonic acid amino acid salt to the hydroxyl group of step (i) is in the range of 10 to 125 mol % in the case where a diol is used in step (ii).

3. The process according to claim 1, wherein steps (i) and (ii) are performed in a single step.

4. A process according to claim 2, wherein steps (i) and (ii) are carried out in one single step.

5. The process according to claim 3, wherein the combined steps (i) and (ii) comprise reacting an organic sulfonic acid, at least one lactam having at least 3 carbon atoms in the lactam ring and at least one linear or branched C 8 -C 36 The alcohol mixture is reacted at a temperature of 80-200°C for 1-30 hours.

6. The process according to claim 4, wherein the combined steps (i) and (ii) comprise reacting an organic sulfonic acid, at least one lactam having at least 3 carbon atoms in the lactam ring and at least one linear or branched C 8 -C 36 The alcohol mixture is reacted at a temperature of 80-200°C for 1-30 hours.

7. The process according to any one of claims 1 and 3 to 6, wherein the alcohol used in step (ii) is selected from alkoxylated monohydric alcohols and alkoxylated polyhydric alcohols.

8. The process according to claim 2, wherein the alcohol used in step (ii) is selected from alkoxylated glycols.

9. The process according to any one of claims 1 to 6 and 8, wherein the lactam used in step (i) is an ε-lactam.

10. The process according to claim 7, wherein the lactam used in step (i) is an ε-lactam.

11. The process according to any one of claims 1 to 6, 8 and 10, wherein the organic sulfonic acid is selected from the group consisting of dodecylbenzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid and methanesulfonic acid.

12. The process according to claim 7, wherein the organic sulfonic acid is selected from the group consisting of dodecylbenzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid and methanesulfonic acid.

13. The process according to claim 9, wherein the organic sulfonic acid is selected from the group consisting of dodecylbenzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid and methanesulfonic acid.

14. The process according to any one of claims 1 to 6, 8 and 10, wherein the organic sulfonic acid is methanesulfonic acid.

15. The method according to claim 7, wherein the organic sulfonic acid is methanesulfonic acid.

16. The method according to claim 9, wherein the organic sulfonic acid is methanesulfonic acid.

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