CN113382992A - Process for preparing alkylene amine compounds - Google Patents

Abstract

The present invention relates to a method for preparing an alkylene amine compound, comprising the steps of: -reacting an alkylene urea compound comprising at least one primary amine group, or at least one cyclic secondary amine group, or at least one primary amine group and at least one cyclic secondary amine group, and at least one cyclic alkylene urea group of formula I with an alkyl halide compound in a reaction medium to form an alkylene amine hydrohalide salt comprising at least one cyclic alkylene urea group of formula IThe alkyl halide compound is selected from the group consisting of haloalkanes and haloalkylaminoalkanes having 2 to 6 halogen atoms, and-reacting the alkylene amine hydrohalide salt with a base to form an alkylene amine compound comprising at least one cyclic alkylene urea group of formula I, wherein a is selected from C2 to C4 alkylene units, optionally substituted with one or more C1 to C3 alkyl groups. In one embodiment, the reaction is carried out in the presence of one or more of ammonia and other alkylene amine compounds. The process of the present invention produces less cyclic and branched by-products and more linear higher alkylene amines, especially more linear ethylene amines selected from L-TETA, L-TEPA and L-PEHA, than conventional processes. Formula I

Description

Process for preparing alkylene amine compounds

Technical Field

The present invention relates to a method for producing an alkylene amine compound. As described in more detail below, within the scope of the present description, the term alkylene amine compound encompasses polyalkylene polyamines and urea-and alkyl-derivatives thereof.

Background

From a commercial point of view, ethyleneamines, especially higher ethyleneamines such as triethylenetetramine (TETA), Tetraethylenepentamine (TEPA) and Pentaethylenehexamine (PEHA) are attractive products.

Currently, the main route to higher polyethyleneamines, i.e. ethyleneamines containing more than three ethylene units, is by reaction of 1, 2-dichloroethane (also known as ethylene dichloride or EDC) with ammonia and/or one or more ethyleneamines. In the substitution reaction, ethyleneamine hydrochloride is formed, which is then neutralized by reaction with caustic to produce ethyleneamine and NaCl. This process is commonly referred to as the EDC route. The EDC route produces a mixture of various ethyleneamines, including linear, branched, and piperazine-containing ethyleneamines. The linear compounds include, for example, Ethylenediamine (EDA), Diethylenetriamine (DETA), linear triethylenetetramine (L-TETA), even higher ethyleneamines such as linear tetraethylenepentamine (L-TEPA), and the like. The piperazine-containing compounds are piperazine (PIP), N-Aminoethylpiperazine (AEP) and N, N' -diaminoethylpiperazine. Branched compounds such as Triaminoethylamine (TAEA) are also formed.

There is a need in the art for an efficient method of making higher ethyleneamines, and broadly, alkyleneamine compounds, that provides the desired compounds in high yields and/or selectivities in an efficient manner. In particular, there is a need in the art for a process that produces less cyclic and branched by-products and produces more linear higher alkylene amine compounds, particularly linear higher alkylene amine compounds that can be converted to linear ethylene amines selected from the group consisting of L-TETA, L-TEPA, and L-PEHA.

Disclosure of Invention

The present invention relates to a method for preparing an alkylene amine compound, comprising the steps of:

-reacting an alkylene urea compound in a reaction medium with an alkyl halide compound selected from haloalkanes and haloalkylaminoalkanes having from 2 to 6 halogen atoms, to form an alkylene amine hydrohalide salt comprising at least one cyclic alkylene urea group of formula I, the alkylene urea comprising at least one primary amine group, or at least one cyclic secondary amine group, or at least one primary amine group and at least one cyclic secondary amine group, and at least one cyclic alkylene urea group of formula I,

formula I

Wherein a is selected from C2 to C4 alkylene units, optionally substituted with one or more C1 to C3 alkyl groups;

-reacting the alkylene amine hydrohalide salt with a base to form an alkylene amine compound comprising at least one cyclic alkylene urea group of formula I.

In this specification, the structure of formula I is sometimes also denoted as-N (A) (CO) N-, particularly where it is part of another general formula.

The process of the present invention makes it possible to prepare higher alkylene amine compounds in an efficient and selective manner while reducing the amount of piperazine-containing by-products and branched by-products. The alkylene amine compound comprising at least one cyclic alkylene urea group can be converted to an alkylene amine by removal of CO. They also have industrial applications per se. Further advantages of the invention and its embodiments will become apparent from the further description.

It is noted that DE3214909 describes quaternary ammonium compounds suitable as additives for improving the adhesion of dyed fabrics, in particular the wet fastness of the dye. The quaternary ammonium compound comprises a cyclic alkylene urea structure. It can be prepared by reacting the tertiary amine group of an alkylene amine containing a tertiary amine group and a cyclic alkylene urea structure with 1, 2-dichloroethane. This reference does not disclose the preparation of the polyalkyleneamine compounds of the present invention.

SU176303 describes a process in which 1, 2-dichloroethane is reacted with urea and the product obtained is then hydrolyzed to form ethylenediamine. The reference does not disclose the use of alkylene ureas.

The present invention will be explained below.

Drawings

Figure 1 shows some of the reactions that may occur in one embodiment of the process of the present invention.

Detailed Description

In the first step of the process of the present invention, an alkylene urea compound is reacted with an alkyl halide compound in a reaction medium.

The alkylene urea compounds comprise at least one primary amine group, or at least one cyclic secondary amine group, or at least one primary amine group and at least one cyclic secondary amine group, and at least one cyclic alkylene urea group of formula I

Formula I

Wherein a is selected from C2 to C4 alkylene units, optionally substituted with one or more C1 to C3 alkyl groups.

In the cyclic alkylene urea group, a is preferably a C2 to C3 alkylene unit, optionally substituted with one or two C1 alkyl groups. A is preferably selected from the group consisting of ethylene, propylene and isopropylene, especially ethylene.

The alkylene urea compounds have at least one cyclic secondary amine group or at least one primary amine group or both. The primary or cyclic secondary amine groups will react with the alkyl halide compound. The cyclic secondary amine group described herein is a group of the formula

Wherein A has the meaning as defined above.

In one embodiment, the alkylene urea compound is a compound of formula II:

formula II: r2- [ -X-A-]_q-N(A)(CO)N-[A-X-]_p-A-NH2

Wherein R2 is selected from H and C1 to C6 alkyl, said alkyl being optionally substituted by one or more groups selected from-OH and-NH 2, in particular zero, one or two groups selected from-OH and-NH 2;

each X is independently selected from the group consisting of-O-, -NR2-, a group of formula I, and a group of formula III:

a is as defined above, p is an integer from 0 to 8, and q is an integer from 0 to 8.

The preferences given above for a apply here as well. A is particularly preferably ethylene.

X is preferably selected from the group consisting of-NH-, a group of formula III, and a group of formula I.

In the case where it is desired to prepare a linear alkylene amine, X is preferably selected from NH and a group of formula I.

R2 is preferably selected from H, ethyl, propyl and isopropyl, especially ethyl, optionally substituted with one or two groups selected from-OH and-NH 2. R2 is particularly preferably ethyl or propyl (aminoethyl or aminoisopropyl), especially ethyl, substituted at the second or third carbon atom (in the case of propyl) by-NH 2.

Since the goal is not always to form a larger molecule for a macromolecule, the sum of p and q may preferably be at most 8, in some embodiments at most 4 or at most 2.

Preferred examples of compounds of formula II are urea adducts of diethylenetriamine (U-DETA), mono-urea adducts of triethylenetetramine (where the urea groups may be located in the terminal ethylene moieties or in the central ethylene moiety (U1-TETA and U2-TETA)), and mono-and bis-urea adducts of tetraethylenepentamine with primary amine groups (U1-TEPA, U2-TEPA, DU1, 3-TEPA). These compounds are particularly attractive if it is desired to prepare linear polyethyleneamines and their corresponding urea products.

Examples of other compounds which can be used in the process of the present invention are compounds consisting of an ethyleneamine chain having a urea group on the nitrogen atom on each side of the terminal ethylene moiety and an ethylene chain on the nitrogen atom on each side of the other ethylene moiety, for example U1P3-TEPA and U1P 4-TEPA.

Generally, in this specification, compounds are named as follows:

the alphabetical code refers to the longest linear ethylene amine chain;

u represents the presence of a cyclic urea group due to the presence of a urea group on two adjacent nitrogen atoms connected by an ethylene moiety, i.e. a group of formula I wherein a is ethylene;

p represents the presence of a piperazine moiety due to the presence of an ethylene moiety on two adjacent nitrogen atoms connected by an ethylene moiety, i.e. a group of formula III wherein both a are ethylene;

the numbers following the U or P prefix represent the corresponding nitrogen atoms in the chain to distinguish the different possible structures;

the letter preceding the letter prefix of U or P represents the number of groups, D represents a double or double group, and T represents three and four, or three and four groups, respectively. When T is used, it can be understood from the context whether it refers to three or four.

In another embodiment, the alkylene urea compound is a compound of formula IV

Formula IV: r2- [ -X-A-]_q-N(A)(CO)N-[A-X-]_p-A-N(A)(A)HN

Wherein R2, X, A, q and p have the above-mentioned meanings. The preferences given above apply here as well.

Preferred examples of the compound represented by the formula IV include urea adduct of piperazinylethylenediamine (UP-TETA).

Mixtures of alkylene urea compounds may also be used.

In the process of the present invention, the alkylene urea compound is reacted with an alkyl halide compound, which will be discussed below. The alkyl halide compound is selected from the group consisting of haloalkanes and haloalkylaminoalkanes having 2 to 6 halogen atoms.

In one embodiment, the alkyl halide compound is an alkyl halide having 2 to 6 halogen atoms, i.e., an alkane substituted with 2 to 6 halogen atoms. In one embodiment, the alkyl halide compound is a dihaloalkane, more specifically a C2-C10 alkane substituted with two halogen atoms, particularly two chlorine atoms. When dihaloalkanes are used, both halogen atoms on the molecule will react with the alkylene urea compound, resulting in the formation of longer molecules. As will be discussed in more detail below, this provides an attractive process for preparing higher alkylene amines. In the case of dihaloalkanes, the halogen atoms may preferably be located at opposite ends of the alkane chain, i.e., alpha-omega dihaloalkanes. It is also possible to use haloalkanes having more than two, for example 3, 4, … … up to 6 halogen atoms, although this may lead to the formation of complex reaction mixtures. The alkyl halide is preferably a C2-C10 dihaloalkane, in particular a C2-C4 dihaloalkane. Particularly preferred compounds are 1, 1-dichloroethane, 1, 2-dichloroethane (usually expressed as dichloroethane or EDC), 1, 2-dichloropropane and 1, 3-dichloropropane, with dichloroethane being particularly preferred. 1,2, 3-Trichloropropane (TCP) may also be attractive.

In one embodiment, the alkyl halide compound is an aminoalkyl halide, otherwise known as a haloalkamino alkane. The haloalkylaminoalkane is an alkane, in particular a C2-C10 alkane substituted by one or more halogen atoms and one or more amino groups. The combination of one or more halogen atoms with one or more amino groups gives compounds with interesting dual reactivity. In this embodiment, the haloalkylaminoalkane may have one, two or more (e.g., up to six) halogen atom substituents, particularly one or two, more particularly one. The haloalkylaminoalkane can have one, two or more (e.g., up to six) amino groups, particularly one or two, more particularly one. The alkane is preferably a C2-C4 alkane. Particularly preferred compounds are 1-chloro-2-amino-ethane, 1-chloro-3-aminopropane and 1-chloro-2-aminopropane or their respective hydrochloride salts.

The halogen atom in the alkyl halide compound may be selected from chlorine, bromine, and iodine. Compounds containing a plurality of halogen atoms can also be used. Although the use of bromine and iodine containing compounds is technically feasible, the use of chlorine containing compounds is generally preferred in view of their greater availability. Furthermore, chloride-containing waste streams are easier to handle than bromide or iodide-containing waste streams. Therefore, the alkyl halide compound is preferably an alkyl chloride compound in general.

It will be apparent to the skilled person that combinations of different alkyl halide compounds may be used in the process of the invention.

The reaction between the alkylene urea compound and the alkyl halide compound is generally carried out at a temperature in the range of 20 to 250 c, in particular at a temperature in the range of 40 to 220 c. In one embodiment, the temperature is in the range of 40 to 150 ℃, in particular in the range of 80 to 120 ℃. In other embodiments, particularly where the reaction medium comprises other amine compounds, higher temperatures may be preferred, for example in the range of 100-220 deg.C, particularly in the range of 120-200 deg.C.

The reaction between the alkylene urea compound and the alkyl halide compound is generally carried out at a pressure of from atmospheric pressure to 150 bar, depending on the components present in the reaction medium and the reaction temperature. Typically, pressure is applied to ensure that the reaction is carried out in the liquid phase at a particular temperature. In some embodiments, particularly when the reaction is carried out at a temperature below 120 ℃, the pressure is typically in the range of 1-10 bar. In other embodiments, particularly where the reaction is carried out in the presence of ammonia, it may be desirable to employ relatively high pressures, for example 10 to 80 bar, especially 20 to 50 bar, as will be discussed below.

The reaction is carried out in a liquid reaction medium, i.e. a reaction medium which is liquid under the reaction conditions. The reaction may be carried out in the presence of a solvent. Suitable solvents are those compounds which enable solvation of the reactants without substantially interfering with the reaction. Water is a suitable solvent. Other suitable solvents include aromatic and aliphatic hydrocarbons such as benzene and xylene, alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol and tert-butanol, esters such as methyl acetate or ethyl acetate and ethers such as diisopropyl ether, diisobutyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dioxane and Tetrahydrofuran (THF). Combinations of solvents may also be used. It is within the knowledge of the skilled person to select suitable solvents.

The time required for the reaction to proceed depends on the degree of conversion desired, the nature and concentration of the reactants, and the reaction temperature. Typically, the reaction time is between 5 minutes and 24 hours, more specifically in the range of 10 minutes to 12 hours, and in some embodiments in the range of 0.5 to 8 hours.

The ratio between the compounds is determined by the number of halogen substituents and the number of primary or cyclic secondary amine groups in the alkyl halide. To ensure that the amount of alkyl halide present is minimized during further processing, the ratio of the number of primary or cyclic secondary amine groups in the reaction medium to the number of halogen atom substituents in the alkyl halide is preferably at least 1:1, especially at least 1.05:1, more especially at least 1.3: 1. The maximum value may be 30: 1. The preferred proportions depend on the components in the reaction mixture. In one embodiment, the maximum value can be up to 10:1, in particular 5:1, generally in the case where the reaction mixture does not comprise ammonia. In embodiments where the reaction medium comprises ammonia, as will be discussed further, higher ratios may be desired, for example from 10:1 to 30:1, particularly from 15:1 to 25: 1.

The reaction product between the alkylene urea compound and the alkyl halide compound is a hydrohalide salt of an alkylene amine or an alkyl amine. The next step in the process of the present invention is to neutralize the salt with a base to form an alkyleneamine comprising at least one cyclic alkyleneurea group, wherein the halide salt is a by-product. The use of strong inorganic bases such as NaOH and KOH is generally preferred from an economic standpoint, and should be desirable since the resulting sodium and potassium halide salts are relatively easy to separate from the alkylene amine containing at least one cyclic alkylene urea group.

The amount of base can be calculated from the amount of alkylene amine or alkyl amine hydrohalide. Typically, the molar ratio of hydroxide ions derived from the base to halide ions in the salt is in the range of from 1:1 to 10:1, in the range of. The base may be provided in dissolved form, for example as an aqueous solution. For reasons of process efficiency, it is preferred to use water as solvent and water as solvent for the base in the reaction of the alkylene urea compound with the alkyl halide compound. The neutralization of the alkylene amine hydrohalide salts is usually carried out at temperatures of from 0 to 200 ℃, in particular from 10 to 150 ℃. The reaction pressure is not critical and may be, for example, in the range from atmospheric pressure to 15 bar, more particularly in the range from atmospheric pressure to 3 bar. Typically, the reaction time is between 1 minute and 24 hours, more specifically in the range of 10 minutes to 12 hours, and in some embodiments in the range of 0.5 to 8 hours.

The product of the reaction is an alkyleneamine comprising at least one cyclic alkyleneurea group, otherwise known as U-alkyleneamine, with halide salts as by-products. The U-alkyleneamine and halide salt may be separated in a variety of ways. For example, the U-alkylene amine can be removed by evaporation. As another example, the halide salt may be removed by crystallization followed by phase separation. As another example, the addition of an antisolvent may result in precipitation of the U-alkyleneamine while the halide salt remains in solution, or vice versa, followed by removal of the precipitate. Combinations of various separation methods may also be employed.

In one embodiment, the present invention enables the selective preparation of high molecular weight polyalkylpolyamine compounds. In the alkylene ureas used as starting materials in the process of the present invention, each C ═ O moiety blocks the reaction of two nitrogen atoms with the alkyl halide compound. Thereby reducing the potential for the formation of various polyalkylpolyamine products. For example, in the case where a primary amine group is partially blocked by C ═ O, the molecule is blocked from forming a piperazine ring.

In one embodiment, the process of the present invention results in the formation of a U-alkyleneamine compound represented by formula V below:

formula V

R2-[-X-A-]q-N(A)(CO)N-[A-X-]p-A-NH-R1-NH-A-[X-A]p-N(A)(CO)N-[A-X]q-R2

In this formula, R2, X, A, p and q have the meanings indicated above. R1 is an alkylene chain derived from an alkyl halide compound and having from 2 to 10 carbon atoms, especially from 2 to 4 carbon atoms. When the alkyl halide compound is a dihaloalkane of the formula Y-R1-Y, Y is a halogen selected from Cl, Br and I, preferably Cl, to give a compound of the formula VI.

For example, ethylene dichloride is reacted with U-DETA in a ratio of 1: 2 to yield DU1,5-PEHA of the formula

As shown in example 1, this compound can be obtained with high selectivity in the process of the invention.

In another example, dichloroethane reacts with U-DETA and piperazine to produce U1-P4-TEPA of the formula

One preferred embodiment of the process of the present invention comprises a process wherein the urea adduct of diethylenetriamine is reacted with dichloroethane to form the diurea adduct of pentaethylenehexamine.

In one embodiment, the process of the present invention produces a U-alkyleneamine product represented by formula VI:

formula VI

R2-[-X-A-]q-N(A)(CO)N-[A-X-]p-A-NH-R1-NH2

Wherein R1, R2, X, A, p and q have the meanings indicated above. The compounds are obtained when the alkyl halide compound is a haloalkylaminoalkane of the formula Y-R1-NH2, wherein Y has the meaning indicated above. The reaction of U-DETA with aminochloroethane to form U-TETA and the reaction of U-TETA with aminochloroethane to form U-TEPA are described below. The two arrows indicate that the reaction comprises two steps, i.e. the formation of the hydrochloride (not shown) and the neutralization reaction, which of course can be carried out in a one-step process.

The U-alkyleneamine may be treated as desired. In one embodiment, CO is removed₂Converting the U-alkyleneamine to the corresponding alkyleneamine, wherein this step is concurrent with the step of reacting the alkyleneamine hydrochloride with a baseOr after it has been performed. This may be referred to as CO₂The treatment of the removal step can be accomplished in a variety of ways.

In one embodiment, the U-alkyleneamine is reacted with water in the liquid phase to remove CO₂The corresponding alkylene amine is formed. The reaction with water is generally carried out at a temperature of at least 150 ℃. If the reaction temperature is below 150 ℃, no significant reaction of the U-alkyleneamine will take place. The reaction is preferably carried out at a temperature of at least 180 ℃, in particular at least 200 ℃, more in particular at least 230 ℃, or even at least 250 ℃. Preferably, the temperature during this step does not exceed 400 ℃, in particular at most 350 ℃, more in particular at most 320 ℃.

The pressure in the process is not critical as long as the reaction medium is in the liquid phase. Values of 0.5 to 100 bar can be considered as usual ranges depending on the desired temperature. Preference is given to carrying out the CO at a pressure of at least 5 bar, in particular at least 10 bar₂A removal step to maintain sufficient amine and water in the medium. In view of the high costs associated with high-pressure equipment, pressures of up to 50 bar, in particular up to 40 bar, may be preferred.

The amount of water depends on the desired degree of conversion and the process conditions. Typically, the amount of water in the feed is at least 0.1 mole of water per mole of urea fraction. Higher amounts are generally used, for example at least 0.1 mole of water per mole of urea moieties, in particular at least 0.5 mole of water per mole of urea moieties. The maximum value is not critical for the process of the invention, but too much water will result in the need for unnecessarily large equipment. Up to 500 moles, particularly up to 300 moles, more particularly up to 200 moles, in some embodiments up to 100 moles, or up to 50 moles of water per mole of cyclic ethylene urea fraction may be considered a typical maximum amount.

Preferably, the CO is carried out during the reaction, for example by venting the reaction vessel, preferably by supplying a stripping gas such as nitrogen or steam₂And (4) removing. In one embodiment, the U-alkyleneamines are reacted in the liquid phase with water in an amount of 0.1 to 20 mol of water per mol of urea fraction at a temperature of at least 230 ℃ with CO removal₂. It was found that the use of a small amount of water and the binding were relatively goodHigh temperature and CO₂The removal thus results in an efficient process with good conversion and low formation of by-products.

In one embodiment, the U-alkylene amine is reacted with an alkylene amine capable of capturing a carbonyl moiety, thereby converting the U-alkylene amine to its corresponding alkylene amine and simultaneously converting the alkylene amine capable of capturing a carbonyl moiety to a U-alkylene amine. This process may be referred to as a carbonyl transfer reaction.

In another embodiment, the U-alkylene amine is reacted with a strong base, i.e. a base having a pKb of less than 1, to form the corresponding alkylene amine and a carbonate. Preferably, a strong inorganic base is used. In one embodiment, the strong inorganic base is selected from metal hydroxides, in particular hydroxides of alkali metals and alkaline earth metals, in particular sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide and barium hydroxide. In one embodiment, the strong inorganic base is selected from metal oxides, in particular oxides of alkali metals and alkaline earth metals, in particular from calcium oxide, magnesium oxide and barium oxide. The strong inorganic base may preferably be selected from sodium hydroxide, potassium hydroxide, magnesium (hydr) oxide and calcium (hydr) oxide. Sodium hydroxide and potassium hydroxide can be particularly preferably used. Other strong inorganic bases, such as ammonium hydroxide, may also be used. It will be apparent to the skilled person that mixtures of various inorganic bases may be used. It is also possible to use compounds which, in addition to the other components, also comprise a base, it being possible to use compounds which are to be converted into inorganic bases in the reaction medium. The molar amount of base can be calculated relative to the molar amount of alkylene urea moieties to be converted. The value may be at least 0.2: 1. If it is desired to convert the alkylene urea moiety completely into the corresponding alkylene amine compound, it may be preferred to use a larger amount, for example a molar ratio of at least 1:1, in particular at least 1.5: 1. It may be preferred to use larger amounts to increase the reaction rate, for example at least 2:1, in particular at least 2.5: 1 in a molar ratio. Since large amounts of base do not contribute to further conversion but lead to additional costs, it is preferred that the molar ratio of base to alkylene urea is at most 20:1, in particular at most 15:1, more in particular at most 10: 1. even smaller amounts of inorganic base were found to be sufficient. More particularly, it was found that good results are obtained when the molar ratio of base to alkylene urea moieties is at most 7.5:1, in particular at most 6.5:1, even more in particular at most 5.5: 1. It was found that the use of a molar ratio of at most 5.5:1 allows complete conversion of the alkylene urea moiety and achieves a high yield of the resulting alkylene amine compound. It may be preferred to employ less base per mole of alkylene urea moiety, for example a molar ratio of up to 5:1, in particular up to 4:1, more in particular up to 3: 1.

The alkali treatment can be carried out, for example, by contacting the substance to be treated with a concentrated aqueous solution of an inorganic alkali. Depending on the nature of the base and the other constituents of the reaction mixture, it is also possible to add the base in solid form and to dissolve it in the reaction medium. It is clear to the person skilled in the art that the aim is to bring the base in solution so that the hydroxyl group can react with CO₂The adduct reacts while avoiding unnecessary dilution of the reaction medium. The reaction may be carried out at a temperature between room temperature and 400 ℃. The temperature and pressure should be selected so that the reaction mixture is in the liquid phase. Higher temperatures are advantageous, since the reaction times are thereby shortened. The reaction can preferably be carried out at a temperature of at least 100 ℃, in particular at least 140 ℃, in particular at least 170 ℃. On the other hand, higher temperatures may lead to the formation of undesirable by-products. It may therefore be preferred to carry out the reaction at a temperature of at most 350 ℃ and in particular at most 280 ℃.

The reaction time can vary within wide limits depending on the reaction temperature, for example between 15 minutes and 24 hours. The reaction time can preferably vary between 1 hour and 12 hours, in particular between 1 hour and 6 hours. When a smaller amount of base is used, a longer reaction time may be required to achieve the desired degree of conversion. Upon completion of the reaction, a reaction mixture comprising an ethylene amine compound and an inorganic base carbonate is obtained. The salt may be removed by methods known in the art, for example by filtration in the case of salts in solid form, or more commonly by phase separation.

Various CO₂Combinations of removal steps are equally possible, e.g. water treatment with CO₂The combination of removal followed by alkaline treatment, optionally in combination with an intermediate removal step.

As noted above, the process of the present invention further comprises the step of reacting an alkylene amine hydrohalide salt with a base to form an alkylene amine comprising at least one cyclic alkylene urea group. If it is intended to convert an alkyleneamine comprising at least one cyclic alkyleneurea group into the corresponding alkyleneamine, the alkyleneamine hydrohalide can be converted into the alkyleneamine by reaction with an inorganic base in a single step. The conversion of U-alkyleneamines to the corresponding alkyleneamines requires more severe conditions than the conversion of alkylene amine hydrohalides to U-alkyleneamines. Thus, if both reactions are combined in one step, the conditions and amount of base should be selected such that both reactions occur. The above conditions should be sufficient for the conversion of the U-alkyleneamine into the corresponding alkyleneamine.

An interesting embodiment of the process of the invention is to utilize the presence of an alkylene urea compound to alter the product distribution of a process in which a dichloroalkane is reacted with one or more ammonia or other alkylene amine compounds to form an alkylene amine, such as the product distribution of a conventional process for the preparation of ethylene amines from EDC and ammonia (usually aqueous ammonia).

In this case, the reaction medium will comprise an alkylene urea compound, an alkyl halide compound selected from polyhaloalkanes or aminohaloalkanes, and one or more of ammonia and other alkylene amine compounds selected from the formula H₂N-[A-X-]_x-A-NH₂An alkyleneamine (wherein X is an integer of 0 to 8), of the formula Y- [ A-X-]_x-A-NH₂A compound represented by the formula (wherein Y is a piperazine ring and x is an integer of 0 to 8), and piperazine. The other alkylene amine compound, if present, may preferably be selected from the formula H₂N-[CH2-CH2-NH-]_x-CH2-CH2-NH₂The ethyleneamine (wherein x is an integer of 0 to 8), the formula Y- [ CH2-CH2-NH-]_x-CH2-CH2-NH₂A compound represented by the formula (wherein Y is a piperazine ring and x is an integer of 0 to 8), and piperazine, in particular selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and piperazine. Of course, combinations of different other alkylene amine compounds may also be used.

The alkyl halide compound will react with the ammonia or other alkylene amine compound to form an alkyl amine hydrohalide salt. The alkyl halide will also react with one or two alkylene urea compounds to form an alkylene amine hydrohalide salt containing at least one cyclic alkylene urea group. Figure 1 shows some of the reactions that may occur when the urea derivative of diethylenetriamine reacts with dichloroethane in the presence of ammonia, ethylenediamine or PIP, and the resulting hydrochloride salt.

Compositions comprising various alkylamine hydrohalide compounds are reacted with a base to convert the salts to the corresponding amine products. Depending on the amount of base and the conversion conditions, the product obtained is a mixture comprising alkylene amine and optionally U-alkylene amine. If U-alkyleneamine is present, it can be converted to an alkyleneamine by the methods given above.

In this embodiment, when reacting a dichloroalkane with one or more ammonia or other alkyleneamines in the presence of an alkylene urea, the ratio between the various compounds is determined by the number of halogen atom substituents in the alkyl halide and the total number of primary amine groups, cyclic secondary amine groups, and ammonia. To ensure that the amount of alkyl halide present during further processing is minimized, it is preferred that the ratio of the total number of primary amine groups, cyclic secondary amine groups, and ammonia in the reaction medium to the number of halogen atom substituents in the alkyl halide is at least 1.05:1, especially at least 1.1: 1. The maximum value may be considered to be 30: 1. Particularly in the case where the system comprises ammonia, a relatively high ratio, for example at least 5:1, may be preferred. In this embodiment, 10:1 to 30:1, in particular 15:1 to 25: 1.

In this embodiment, the reaction of the dichloroalkane with ammonia or one or more other alkyleneamines in the presence of the alkylene urea may preferably be carried out at relatively high temperatures, for example in the range of 100-220 deg.C, especially in the range of 120-200 deg.C. In this embodiment, in particular in the case of ammonia as reactant, it may be preferred to work at relatively high pressures, for example in the range from 10 to 80 bar, in particular from 20 to 50 bar. The general scope of the process of the invention given above is equally applicable here.

The composition of the resulting product is determined, on the one hand, by the relative amount of alkylene urea compound and, on the other hand, by the total amount of ammonia and other alkylene amine compounds. In order to make a meaningful change in product composition compared to a process carried out in the absence of an alkylene urea compound, the ratio of the total amount of primary and cyclic secondary amine groups derived from the alkylene urea compound to the total amount of primary and cyclic secondary amine groups derived from ammonia and other alkylene amine compounds is generally preferably at least 0.1:1, especially at least 0.2: 1. The maximum value is usually at most 20:1, in particular at most 10: 1. If this value is exceeded, the amount of ammonia and other alkylene amine compounds will be so low that their effect on the product composition may be insignificant. It is within the ability of the skilled person to determine suitable ratios of the different raw materials.

An example of a process according to this embodiment of the invention is as follows, in which a dichloroalkane is reacted with ammonia or one or more of other alkylene amine compounds and an alkylene urea compound:

reaction of U-DETA with dichloroethane and ammonia to U1-TETA

Reaction of U-DETA with dichloroethane and ethylenediamine to U1-TEPA

Reaction of U-DETA with dichloroethane and piperazine to form U1P4-TEPA

It will be apparent to the skilled person that the product formed in this reaction may also be reacted with dichloroethane, as well as ammonia or an ethyleneamine compound or piperazine, which may also be reacted with dichloroethane, thus leading to the formation of a reaction mixture comprising the various components. The presence of the alkylene urea compound in the reaction mixture results in the formation of more linear ethylene amine compounds and results in the formation of less other piperazine moieties than would be the case in the absence of the alkylene urea moieties.

The reaction mixture may be treated as desired. In the case of ammonia, it may be attractive to recover the ammonia-containing gas stream from the product and recycle it to the process. When the reaction mixture contains a cyclic ethylene urea compound, the entire reaction mixture can be charged under conditions such that the ethylene urea moiety is converted to an ethylene amine moiety. However, it is also possible to subject the reaction mixture to a separation step to obtain a fraction having a reduced content of cyclic ethylene urea compound and a fraction having an increased content of cyclic ethylene urea compound, and to subject the latter fraction to conditions under which the ethylene urea fraction is converted into an ethylene amine fraction. In general, the reaction products can be separated as desired by methods known in the art, for example by distillation, and the fractions can be worked up as desired, for example isolated as products or recycled as starting materials.

The starting material for the process of the present invention is an alkylene urea compound comprising at least one primary amine group, at least one cyclic secondary amine group, or at least one primary amine group and at least one cyclic secondary amine group, and at least one cyclic alkylene urea group of formula I. Such compounds are obtainable by reacting an alkylene amine compound having a linear-NH-a-NH-moiety with a carbonyl transfer agent at a suitable reaction temperature. Suitable carbonyl transfer agents are compounds containing A carbonyl moiety that can be transferred to the-HN-A-NH-moiety. Examples include carbon dioxide and organic compounds in which the carbonyl moiety can be transferred as described above. Organic compounds in which the carbonyl moiety is transferable include urea and its derivatives; linear and cyclic alkylene ureas, particularly cyclic alkylene ureas, mono-or disubstituted alkylene ureas, alkyl and dialkyl ureas; linear and cyclic carbamates; organic carbonates and derivatives or precursors thereof. The derivatives or precursors may include, for example, ionic compounds such as organic carbonates or bicarbonates, carbamates, and related salts. Preferably, the carbonyl transfer agent is CO₂Or an organic compound which is suitable as a carbonyl transfer agent and in which the alkylene group is ethylene, or an ethylene urea compound or ethylene carbonate, more preferably a carbonyl transfer agent is added at least partly in the form of carbon dioxide or in the form of an ethylene urea compound, i.e. a compound containing a group of formula I. The urea compounds can be prepared by combining an alkylene amine compound having a linear-NH-a-NH-moiety with a carbonyl transfer agent and heating the mixture to a temperature at which reaction occurs. This reaction is a known reaction and need not be described in detail herein. Depending on the choice of carbonyl transfer agent and the reaction conditions, the formation of the urea compound and the reaction with the alkyl halide can be combined. However, given that compounds having a carbonyl moiety are commonly used to block amine groups, it is generally preferred to first prepare the alkylene urea compound and then react the alkylene urea compound with the alkyl halide compound.

The process of the invention and its steps may be carried out as a batch operation, a feed-batch operation or a continuous operation, for example in a series connected continuous flow reactor. Continuous operation may be preferred depending on the scale of operation.

In each formula used herein, all choices of A, R2 and X are independent of each other unless specifically stated otherwise. Preferably all alkylene groups are ethylene groups.

It is obvious to the skilled person that various embodiments of the invention can be combined, unless they are mutually contradictory.

The invention is illustrated by the following examples, but is not limited thereto or thereby.

Examples

Example 1: reaction of EDC with U-DETA

2.5g (25mmol) EDC are slowly added at 50 ℃ to a mixture of 6.9g (53mmol) U-DETA and 5mL distilled water. After completion of the EDC addition, the reaction mixture was heated at 105 ℃ for 4 hours to allow U-DETA to react with EDC to form the hydrochloride salt of DU1, 5-PEHA:

to convert the dihydrochloride salt of DU1,5-PEHA into DU1,5-PEHA, the reaction mixture was cooled to 50 ℃ at which time 4.2mL (80mmol) of 50 wt% aqueous NaOH solution were added. The mixture was then held at 50 ℃ for an additional 30 minutes. Subsequently, water was removed by evaporation under reduced pressure. 50mL of ethanol was added and the mixture was stirred for 5 minutes. The precipitate thus formed was removed by filtration and dried under reduced pressure to give about 9g of a pale yellow viscous substance containing DU-1, 5-PEHA. The reaction scheme is as follows:

to convert DU-1,5-PEHA into L-PEHA, 4g of the pale yellow viscous substance comprising DU-1,5-PEHA, 3.2g (80mmol) NaOH and 15mL of distilled water were introduced into a 45mL autoclave.By using N₂(g) The vessel was purged and then heated to 220 ℃ over 40 minutes and heated at 220 ℃ for 2.5 hours. After cooling to room temperature, the samples were removed and analyzed by gas chromatography with a flame ionization detector (GC-FID) using an internal standard. According to GC-FID analysis, the sample contained 53% DETA, 33% L-PEHA and 12% (U) -PEHA. No traces of piperazine-containing or branched (U) -PEHA isomers were found. From a commercial point of view, high selectivity and yield for L-PEHA without producing large quantities of high molecular weight alkylene amine homologues is very attractive. The reaction scheme is as follows.

Example 2: reaction of EDC with U-DETA and Ammonia

A mixture of U-DETA (4.70g,36.4mmol), EDC (3.60g,36.4mmol) and ammonia (17.7g, 35%, 364mmol) was heated in an autoclave at 100 ℃ for 4 h. The mixture was allowed to cool, NaOH (2.91g, 72.8mmol) was added and the resulting mixture was analyzed by GC-FID to give U1-TETA in 10% GC yield. Higher yields can be obtained by optimizing the reaction.

Example 3: reaction of EDC, U-DETA and piperazine

A mixture of U-DETA (20.4g, 0.16mol), piperazine (13.6g, 0.16mol) and water (6.4g) was heated to 65 ℃ in a round bottom flask equipped with an internal thermometer, reflux condenser and dropping funnel. EDC (6.3g, 0.06mol) was added slowly via the dropping funnel. After 20 minutes (end of the exothermic reaction), 50 wt.% were added

% aqueous NaOH solution (5.4g, 0.13mol), the mixture was stirred at 65 ℃ for 15 minutes and then analyzed by GC-MS and GC-FID. The reaction is shown below.

This reaction produced 6% U1P4-TEPA, 18% DP-TETA and 6% TP-PEHA (GC area%), while still leaving a significant amount of piperazine and U-DETA as they are in excess molar amounts relative to the amount of EDC. High boiling components such as DU1,5-PEHA and higher U-compounds may be present but cannot be detected with the GC-FID and GC-MS devices currently used.

Example 4: reaction of DETA (comparative) and U-DETA (invention) with EDC

To investigate the influence of the cyclic urea groups on the selectivity of the reaction with EDC, experiments were carried out using DETA (comparative examples A and B) or U-DETA (inventive example 4.1) as starting material.

DETA or U-DETA was reacted with EDC (5M in water) at 100 ℃ for 30 minutes, respectively. The reaction mixture was then treated with 50 wt% aqueous NaOH (2.1 equivalents relative to EDC). After removal of salts and water, the product mixture was analyzed by GC-MS and GC-FID. The GC-FID results are given in the following table in wt%.

n.d. -, not detected

As can be seen from the table, the reaction of U-DETA with EDC resulted in significantly higher yields of L-PEHA product, while producing only a small amount of AEP, as compared to the reaction of DETA with EDC.

Claims (14)

1. A method of preparing an alkylene amine compound comprising the steps of:

-reacting an alkylene urea compound in a reaction medium with an alkyl halide compound selected from haloalkanes and haloalkylaminoalkanes having from 2 to 6 halogen atoms, to form an alkylene amine hydrohalide salt comprising at least one cyclic alkylene urea group of formula I, the alkylene urea comprising at least one primary amine group, or at least one cyclic secondary amine group, or at least one primary amine group and at least one cyclic secondary amine group, and at least one cyclic alkylene urea group of formula I,

formula I

Wherein a is selected from C2 to C4 alkylene units, optionally substituted with one or more C1 to C3 alkyl groups; and

-reacting the alkylene amine hydrohalide salt with a base to form an alkylene amine compound comprising at least one cyclic alkylene urea group of formula I.

2. The process according to claim 1, wherein a is a C2 to C3 alkylene unit, optionally substituted with one or two C1 alkyl groups, a preferably being selected from ethylene, propylene and isopropylene, especially ethylene.

3. The process according to any one of the preceding claims, wherein the alkylene urea compound used as starting material is a compound of formula II:

formula II: r2- [ -X-A-]_q-N(A)(CO)N-[A-X-]_p-A-NH2

Wherein

R2 is selected from H and C1 to C6 alkyl optionally substituted with one or more groups selected from-OH and-NH 2, in particular zero, one or two groups selected from-OH and-NH 2;

each X is independently selected from the group consisting of-O-, -NR2-, a group of formula I, and a group of formula III:

the meaning of A is as described above,

p is an integer of 0 to 8, and

q is an integer of 0 to 8.

4. The process according to any one of the preceding claims, wherein the alkylene urea compound used as starting material is a compound of formula IV:

formula IV: r2- [ -X-A-]_q-N(A)(CO)N-[A-X-]_p-A-N(A)(A)HN

Wherein the meanings of R2, X, A, q and p are as described above.

5. The process according to any one of the preceding claims, wherein the alkyl halide compound is an alkyl chloride compound.

6. The process according to any one of the preceding claims, wherein the alkyl halide selected from haloalkanes having from 2 to 6 halogen atoms is selected from 1,2, 3-trichloropropane or C2-C10 dihaloalkanes, more particularly C2-C4 dihaloalkanes, in particular 1, 1-dichloroethane, 1, 2-dichloroethane (commonly known as dichloroethane or EDC), 1, 2-dichloropropane or 1, 3-dichloropropane, with dichloroethane being particularly preferred.

7. The process according to any one of the preceding claims, wherein the alkyl halide is selected from the group consisting of haloaminoalkanes, in particular C2-C10 alkanes, preferably having 1 to 6, in particular 1 or 2, more in particular 1 halogen atom substituent(s), and one or more amino group(s), preferably having 1 to 6, in particular 1 or 2, more in particular 1 amino group(s), preferably C2-C4 alkanes, particularly preferably 1-chloro-2-amino-ethane, 1-chloro-3-aminopropane, 1-chloro-2-aminopropane or the respective hydrochloride thereof.

8. The process according to the invention, wherein the step of reacting the alkylene amine hydrohalide with a base to form an alkylene amine comprising at least one cyclic alkylene urea group of formula I is carried out using a strong inorganic base, in particular NaOH or KOH.

9. A process according to any one of the preceding claims wherein the cyclic alkylene urea product formed in the process of the invention is a compound of formula V or a compound of formula VI:

formula V

R2-[-X-A-]q-N(A)(CO)N-[A-X-]p-A-NH-R1-NH-A-[X-A]p-N(A)(CO)N-[A-X]q-R2

Formula VI

R2-[-X-A-]q-N(A)(CO)N-[A-X-]p-A-NH-R1-NH2

Wherein R2, X, A, p and q have the meanings given above, and R1 is an alkylene chain derived from the alkyl halide, having from 2 to 10 carbon atoms, in particular from 2 to 4 carbon atoms.

10. The process of claim 1 wherein the urea adduct of diethylenetriamine is reacted with dichloroethane to form a diurea adduct of pentaethylenehexamine.

11. The method according to any of the preceding claims, comprising CO₂A removal step comprising removing CO₂In the presence of a catalyst, wherein the step is carried out simultaneously with or subsequent to the step of reacting an alkylene amine hydrochloride with an inorganic base.

12. A process according to any one of the preceding claims wherein the reaction medium comprises one or more of an alkylene urea compound, an alkyl halide compound selected from polyhaloalkanes or aminohaloalkanes, and ammonia and other alkylene amine compounds selected from the formula H₂N-[AX-]_xA-NH₂An alkyleneamine wherein X is an integer of 0 to 8, of the formula Y- [ A-X-]_xA-NH₂A compound represented by formula (I), wherein Y is a piperazine ring and x is an integer of 0 to 8, and piperazine.

13. The process according to claim 12, wherein the alkyl halide compound is dichloroethane and the other alkylene amine compound, if present, is selected from the formula H₂N-[CH2-CH2-NH-]_x-CH2-CH2-NH₂The ethyleneamines of the formula, where x is an integer from 0 to 8, Y- [ CH2-CH2-NH-]_x-CH2-CH2-NH₂A compound of formula (I), wherein Y isPiperazine ring and x is an integer from 0 to 8, and piperazine, in particular selected from ethylenediamine, diethylenetriamine, triethylenetetramine and piperazine.

14. A process according to any one of the preceding claims wherein the process comprises the step of reacting an alkylene amine compound having a linear-NH-a-NH-group with a carbonyl donor to prepare an alkylene urea compound comprising at least one primary amine group and at least one cyclic alkylene urea group of formula I.

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