CN113382992B

CN113382992B - Process for preparing alkylene amine compounds

Info

Publication number: CN113382992B
Application number: CN202080012661.XA
Authority: CN
Inventors: E·N·坎特兹; K·F·拉克; R·K·伯格; R·埃德文森; A·J·B·登·凯特; 伊娜·埃勒斯; H·万·丹; M·J·T·瑞秋马克斯; R·维尼曼; S·约维察; L·F·祖贝尔
Original assignee: Norion Chemicals International Ltd
Current assignee: Norion Chemicals International Ltd
Priority date: 2019-02-07
Filing date: 2020-02-04
Publication date: 2024-07-09
Anticipated expiration: 2040-02-04

Abstract

The present invention relates to a process for preparing an alkylene amine compound, comprising the steps of: -reacting an alkylene urea compound selected from the group consisting of haloalkanes and haloalkylalkanes having 2-6 halogen atoms with an alkyl halide compound in a reaction medium to form an alkylene amine halide salt comprising at least one cyclic alkylene urea group of formula I, said 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, and-reacting said alkylene amine halide 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 the group consisting of 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 fewer cyclic and branched byproducts and produces more linear higher alkylene amines, particularly more linear ethylene amines selected from the group consisting of L-TETA, L-TEPA and L-PEHA, than conventional processes. I is a kind of

Description

Process for preparing alkylene amine compounds

Technical Field

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

Background

Ethylene amines, particularly higher ethylene amines such as triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and Pentaethylenehexamine (PEHA), are attractive products from a commercial point of view.

Currently, the main route to higher polyethylene amines, i.e. ethylene amines containing more than three ethylene units, is by reaction of 1, 2-dichloroethane (also known as ethylene dichloride or EDC) with aqueous ammonia and/or one or more ethylene amines. Ethylene amine hydrochloride is formed in the substitution reaction and then neutralized by reaction with caustic to yield ethylene amine and NaCl. This process is commonly referred to as the EDC pathway. The EDC pathway produces a mixture of various ethyleneamines, including linear, branched, and piperazine-containing ethyleneamines. Such straight chain 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 Triethylamine (TAEA) are also formed.

There is a need in the art for an efficient process for the manufacture of higher ethyleneamines, and broadly alkylene amine compounds, which provides the desired compounds in an efficient manner in high yields and/or selectivities. In particular, there is a need in the art for a process that produces fewer cyclic and branched byproducts 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 process for preparing an alkylene amine compound, comprising the steps of:

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

I is a kind of

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

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

In the present specification, the structure of formula I is sometimes also denoted as-N (A) (CO) N-especially when it is part of another formula.

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

Notably, DE3214909 describes quaternary ammonium compounds suitable for use as additives to improve dye fabric adhesion (in particular dye wet fastness). The quaternary ammonium compound comprises a cyclic alkylene urea structure. It can be prepared by reacting a tertiary amine group of an alkylene amine comprising a tertiary amine group and a cyclic alkylene urea structure with 1, 2-dichloroethane. The reference does not disclose the preparation of the polyalkylene amine compounds of the present invention.

SU176303 describes a process in which 1, 2-dichloroethane is reacted with urea and the resulting product is then hydrolysed 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 reactions that may occur in one embodiment of the method 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 compound comprises 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

I is a kind of

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 ethylene, propylene and isopropylene, in particular ethylene.

The alkylene urea compound has at least one cyclic secondary amine group or at least one primary amine group or both. Primary or cyclic secondary amine groups will react with the alkyl halide compound. The cyclic secondary amino group is a group shown as the following formula

Wherein A has the meaning given 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 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;

x is each 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 from 0 to 8, and q is an integer from 0 to 8.

The preferences given above for A apply here as well. Particularly preferably A is 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 the group of formula I.

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

Since the goal is not always a reaction to form larger molecules for the macromolecules, 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 the compounds of formula II are urea adducts of diethylenetriamine (U-DETA), monourea adducts of triethylenetetramine in which the urea groups may be located in terminal ethylene moieties or in central ethylene moieties (U1-TETA and U2-TETA), and monourea and bisurea adducts of tetraethylenepentamine with primary amine groups (U1-TEPA, U2-TEPA, DU1, 3-TEPA). These compounds are particularly attractive if linear polyethylene amines and their corresponding urea products are to be prepared.

Examples of other compounds which can be used in the process of the invention are compounds composed of ethylene amine chains having urea groups on the nitrogen atoms on each side of the terminal ethylene moiety and ethylene chains on the nitrogen atoms on each side of the other ethylene moiety, such as U1P3-TEPA and U1P4-TEPA.

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

the letter code refers to the longest straight ethyleneamine chain;

U represents the presence of a cyclic urea group due to the presence of a urea group on two adjacent nitrogen atoms linked 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 top of two adjacent nitrogen atoms linked by an ethylene moiety, i.e. two groups of formula III wherein a is ethylene;

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

the letter preceding the U or P prefix represents the number of groups, D represents a double or double group, T represents three and four, or three and four groups, respectively. When T is used, it is 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 abovementioned meanings. The preferences given above apply here as well.

Preferred examples of the compound of formula IV include urea adducts of piperazinylethylethylenediamine (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 haloalkylalkanes 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. Haloalkanes having more than two, for example 3, 4, … … up to 6 halogen atoms, may also be used, although this may lead to the formation of complex reaction mixtures. The haloalkanes are generally preferably C2-C10 dihaloalkanes, in particular C2-C4 dihaloalkanes. Particularly preferred compounds are 1, 1-dichloroethane, 1, 2-dichloroethane (generally denoted 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, alternatively referred to as a halogenated aminoalkyl alkane. A haloaminoalkane is an alkane, in particular a C2-C10 alkane substituted with 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 the compound interesting dual reactivity. In this embodiment, the haloaminoalkane may have one, two, or more (e.g., up to six) halogen atom substituents, particularly one or two, more particularly one. The haloaminoalkane may 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 hydrochlorides.

The halogen atoms in the alkyl halide compound may be selected from chlorine, bromine and iodine. Compounds containing multiple halogen atoms may 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 easier availability. In addition, chloride-containing waste streams are easier to handle than bromide-or iodide-containing waste streams. Thus, the alkyl halide compound is generally preferably an alkyl chloride compound.

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 20-250 ℃, in particular at a temperature in the range of 40-220 ℃. In one embodiment, the temperature is in the range of 40-150 ℃, in particular in the range of 80-120 ℃. In other embodiments, particularly where the reaction medium comprises other amine compounds, higher temperatures, for example in the range of 100 to 220 ℃, particularly in the range of 120 to 200 ℃, may be preferred.

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 proceeds in the liquid phase at a specific 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, as will be discussed below, it may be desirable to employ relatively high pressures, for example 10-80 bar, particularly 20-50 bar.

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 that enable the reactants to be solvated 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 or ethyl acetate and ethers such as diisopropyl ether, diisobutyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dioxane and Tetrahydrofuran (THF). Solvent combinations may also be used. The choice of suitable solvents is within the knowledge of the skilled person.

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 in the alkyl halide and the number of primary or cyclic secondary amine groups. To ensure that the amount of alkyl halide present during further processing is minimized, the ratio of the number of primary amine 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, particularly at least 1.05:1, more particularly at least 1.3:1. The maximum value may be 30:1. The preferred ratio depends on the components in the reaction mixture. In one embodiment, the maximum value may be up to 10:1, in particular may be 5:1, in general in the case of reaction mixtures which do not contain ammonia. In embodiments where the reaction medium comprises ammonia, as will be further discussed, higher ratios may be desired, such as 10:1 to 30:1, particularly 15:1 to 25:1.

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

The amount of base can be calculated based on the amount of alkylene amine or alkyl amine hydrohalate. Typically, the molar ratio of hydroxide ions derived from the base to halide ions in the salt is in the range of 1:1 to 10: 1. The base may be provided in dissolved form, for example in the form of an aqueous solution. For reasons of process efficiency, it is preferable to use water as a solvent and water as a solvent of a base in the reaction of the alkylene urea compound with the alkyl halide compound. Neutralization of the alkylene amine hydrohalates is generally 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 of atmospheric pressure to 15 bar, more particularly in the range of 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 alkylene amine containing at least one cyclic alkylene urea group, otherwise known as U-alkylene amine, and the halide salt is a by-product. The U-alkylene amine and halide salt may be separated in a variety of ways. For example, the U-alkylene amine may be removed by evaporation. For another example, the halide salt may be removed by crystallization followed by phase separation. For another example, the addition of an antisolvent may result in precipitation of the U-alkylene amine while the halide salt remains in solution and vice versa, with subsequent 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 urea used as starting material in the process of the invention, each c=o moiety prevents two nitrogen atoms from reacting with the alkyl halide compound. Thereby reducing the potential for the formation of multiple polyalkylpolyamine products. For example, in the case where primary amine groups are blocked by a c=o moiety, 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-alkylene amine compound of formula V:

V (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 from an alkyl halide having 2 to 10 carbon atoms, in particular 2 to 4 carbon atoms. When the alkyl halide compound is a dihaloalkane of the formula Y-R1-Y, a compound of the formula VI is obtained, wherein Y is a halogen selected from Cl, br and I, preferably Cl.

For example, ethylene dichloride with U-DETA at 1:2 to produce DU1,5-PEHA shown in the following formula

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

As another example, dichloroethane is reacted with U-DETA and piperazine to form U1-P4-TEPA of the formula

A 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 biurea adduct of pentaethylenehexamine.

In one embodiment, the process of the present invention produces a U-alkylene amine product of formula VI:

VI (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 given above. When the alkyl halide compound is a halogenated amino alkane of the formula Y-R1-NH2, wherein Y has the meaning as described above, the compound is obtainable. The reaction of U-DETA with aminochloroethane to form U-TETA and the reaction of U-TETA with aminochloroethane to form U-TEPA will be described below. The two arrows indicate that the reaction comprises two steps, namely the formation of the hydrochloride salt (not shown) and the neutralization reaction, which of course may be carried out in a one-step process.

The U-alkylene amine may be treated as desired. In one embodiment, the removal of CO ₂ converts the U-alkylene amine to the corresponding alkylene amine, wherein this step is performed simultaneously with or subsequent to the step of reacting the alkylene amine hydrochloride with the base. This process, which may be referred to as the CO ₂ removal step, may be accomplished in a variety of ways.

In one embodiment, the U-alkylene amine is reacted with water in the liquid phase to remove CO ₂ to form the corresponding alkylene amine. The reaction with water is generally carried out at a temperature of at least 150 ℃. If the reaction temperature is less than 150 ℃, the U-alkylene amine will not react significantly. 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 is not more than 400 ℃, in particular at most 350 ℃, more in particular at most 320 ℃.

The pressure in the process is not critical, provided that the reaction medium is in the liquid phase. The value 0.5 to 100 bar can be considered as the usual range, depending on the desired temperature. The CO ₂ removal step is preferably carried out at a pressure of at least 5 bar, especially at least 10 bar, 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 degree of conversion desired 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, for example at least 0.1 mole of water per mole of urea fraction, in particular at least 0.5 mole of water per mole of urea fraction, are generally used. The maximum value is not critical for the process of the present 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 moiety may be considered a typical maximum amount.

Preferably, the CO ₂ removal is performed during the reaction, for example by venting the reaction vessel, preferably by providing a stripping gas such as nitrogen or steam. In one embodiment, the U-alkylene amine is reacted in the liquid phase with water in an amount of 0.1 to 20 moles of water per mole of urea moiety at a temperature of at least 230 ℃ while removing CO ₂. It was found that the use of small amounts of water in combination with the relatively high temperature and CO ₂ removal resulted in an efficient process with good conversion and low by-product formation.

In one embodiment, the U-alkylene amine is reacted with an alkylene amine capable of capturing the carbonyl moiety, thereby converting the U-alkylene amine to its corresponding alkylene amine and simultaneously converting the alkylene amine capable of capturing the carbonyl moiety to the 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 less than 1, to form the corresponding alkylene amine and carbonate. Preferably, a strong inorganic base is used. In one embodiment, the strong inorganic base is selected from metal hydroxides, in particular alkali and alkaline earth metal hydroxides, 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 may 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 contain, in addition to other components, bases, or else compounds which are converted into inorganic bases in the reaction medium. The molar amount of base can be calculated relative to the molar amount of alkylene urea moiety to be converted. The value may be at least 0.2:1. If it is desired to convert the alkylene urea moiety completely to the corresponding alkylene amine compound, it may be preferable to use a greater amount, for example in a molar ratio of at least 1:1, in particular at least 1.5:1. It may be preferable to use a greater amount to increase the reaction rate, for example at least 2:1, in particular at least 2.5:1 in molar ratio. Since large amounts of base not only do not contribute to further conversion but also 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, good results have been found to be obtained when the molar ratio of base to alkylene urea moieties is at most 7.5:1, particularly at most 6.5:1, even more particularly at most 5.5:1. It was found that the use of a molar ratio of up to 5.5:1 allows for a complete partial conversion of the alkylene urea 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 at most 5:1, in particular at most 4:1, more in particular at most 3:1.

The alkali treatment may be carried out, for example, by contacting the substance to be treated with a concentrated aqueous inorganic alkali solution. Depending on the nature of the base and other constituents of the reaction mixture, the base may also be added in solid form and dissolved in the reaction medium. It will be clear to the person skilled in the art that the aim is to keep the base in solution so that the hydroxyl groups can react with the CO ₂ adduct 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. A higher temperature is advantageous because the reaction time is thereby reduced. The reaction may 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 undesired by-product formation. It may thus be preferred to carry out the reaction at a temperature of up to 350 ℃, in particular up to 280 ℃.

The reaction time may vary within a wide range depending on the reaction temperature, for example between 15 minutes and 24 hours. The reaction time may preferably vary from 1 hour to 12 hours, in particular from 1 hour to 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 is obtained comprising the ethyleneamine compound and the inorganic base carbonate. Salts 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.

Combinations of various CO ₂ removal steps are equally possible, such as a combination of water treatment with CO ₂ removal, followed by an alkali treatment, optionally in combination with an intermediate removal step.

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

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

In this case, the reaction medium will comprise one or more of an alkylene urea compound, an alkyl halide compound selected from polyhalogenated alkanes or aminoalkyl alkanes, and ammonia and other alkylene amine compounds selected from alkylene amines of formula H ₂N-[A-X-]_x-A-NH₂ (where X is an integer from 0 to 8), compounds of formula Y- [ A-X- ] _x-A-NH₂ (where Y is a piperazine ring and X is an integer from 0 to 8), and piperazine. The other alkylene amine compound, if present, may preferably be selected from the group consisting of ethylene amines of the formula H ₂N-[CH2-CH2-NH-]_x-CH2-CH2-NH₂ (wherein x is an integer from 0 to 8), compounds of the formula Y- [ CH2-CH2-NH- ] _x-CH2-CH2-NH₂ (wherein Y is a piperazine ring and x is an integer from 0 to 8), and piperazine, in particular selected from ethylene diamine, diethylene triamine, triethylene tetramine and piperazine. Of course, combinations of various 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 hydrohalate. The alkyl halide will also react with one or both of the alkylene urea compounds to form an alkylene amine hydrohalate comprising at least one cyclic alkylene urea group. Figure 1 shows some reactions that may occur when urea derivatives of diethylenetriamine are reacted with dichloroethane in the presence of ammonia, ethylenediamine or PIP, as well as the resulting hydrochloride salt.

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

In this embodiment, the ratio between the various compounds when reacting a dichloroalkane with one or more ammonia or other alkylene amines in the presence of an alkylene urea 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 be at least 1.05:1, especially at least 1.1:1. 30:1 may be considered the maximum. Particularly in case the system comprises ammonia, a relatively high ratio may be preferred, e.g. at least 5:1. In this embodiment, 10:1 to 30:1, in particular 15:1 to 25:1.

In this embodiment, when reacting the dichloroalkane with one or more of ammonia or other alkylene amine in the presence of alkylene urea, it may be preferred to operate at a relatively high temperature, for example in the range of 100-220 ℃, in particular in the range of 120-200 ℃. In this embodiment, in particular in the case of ammonia as reactant, it may be preferable to carry out 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 method of the invention given above applies equally here.

The composition of the resulting product is determined on the one hand by the relative amounts of alkylene urea compounds and on the other hand by the total amount of ammonia and other alkylene amine compounds. In order to make a meaningful change in the 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 originating from the alkylene urea compound to the total amount of primary and cyclic secondary amine groups originating from ammonia and other alkylene amine compounds is generally preferably at least 0.1:1, in particular at least 0.2:1. The maximum value is generally at most 20:1, in particular at most 10:1. If this value is exceeded, the amounts of ammonia and other alkylene amine compounds will be so low that their effect on the composition of the product may be insignificant. It is within the ability of the skilled artisan to determine the appropriate proportions of the different materials.

Examples of methods according to this embodiment of the invention are as follows, wherein dichloroalkane is reacted with one or more of ammonia or other alkylene amine compounds and an alkylene urea compound:

Reaction of U-DETA with dichloroethane and ammonia to give U1-TETA

Reaction of U-DETA with dichloroethane and ethylene diamine to give U1-TEPA

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

It will be apparent to the skilled person that the products formed in this reaction may also be reacted with dichloroethane, and that ammonia or ethylene amine compounds or piperazine may also be reacted with dichloroethane, thereby resulting in the formation of a reaction mixture comprising the various components. The presence of an alkylene urea compound in the reaction mixture results in the formation of more linear ethylene amine compounds and in the formation of fewer other piperazine moieties than if no alkylene urea moiety were present.

The reaction mixture may be treated as desired. In the case of ammonia, it may be attractive to recover an ammonia-containing gas stream from the product and recycle it in the process. When the reaction mixture contains a cyclic ethyleneurea compound, the entire reaction mixture may be charged under conditions such that the ethyleneurea moiety is converted to an ethyleneamine 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 compounds and a fraction having an increased content of cyclic ethylene urea compounds, and subject the latter fraction to conditions under which the ethylene urea fraction is converted into an ethylene amine fraction. In general, the reaction product may be isolated as desired by methods known in the art, for example by distillation, and the various fractions may be treated as desired, for example as product separation or recycled as feed.

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 may be obtained 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. Wherein the carbonyl moiety transferable organic compound comprises urea and derivatives thereof; linear and cyclic alkylene ureas, in particular cyclic alkylene ureas, mono-or di-substituted 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, carbamic acid and related salts. Preferably the carbonyl transfer agent is CO ₂ or an organic compound suitable for use as a carbonyl transfer agent and wherein the alkylene group is ethylene, or an ethylene urea compound or ethylene carbonate, more preferably the carbonyl transfer agent is added at least partially 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 compound may 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 urea compounds and the reaction with alkyl halides may be combined. However, considering that compounds having a carbonyl moiety are commonly used to block amine groups, it is generally preferred to first prepare an alkylene urea compound and then react the alkylene urea compound with an 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 (e.g. in continuous flow reactors connected in series). Depending on the scale of operation, continuous operation may be preferred.

In each of the formulae used herein, all choices of A, R and X are independent of each other, unless specifically indicated otherwise. Preferably all alkylene groups are ethylene groups.

It will be obvious to the skilled person that the various embodiments of the invention may be combined unless they contradict each other.

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

Examples

Example 1: EDC reaction with U-DETA

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

To convert the dihydrochloride of DU1,5-PEHA to DU1,5-PEHA, the reaction mixture was cooled to 50deg.C, at which point 4.2mL (80 mmol) of 50wt% aqueous NaOH was added. The mixture was then allowed to stand at 50℃for an additional 30 minutes. Next, 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 to L-PEHA, 4g of the pale yellow viscous material containing DU-1,5-PEHA, 3.2g (80 mmol) NaOH and 15mL distilled water were charged into a 45mL autoclave. The vessel was purged with N ₂ (g) and then heated to 220 ℃ over 40 minutes and at 220 ℃ for 2.5 hours. After cooling to room temperature, the samples were removed and analyzed by gas chromatography in combination with flame ionization detector (GC-FID) using internal standards. According to GC-FID analysis, the sample contained 53% DETA, 33% L-PEHA and 12% (U) -PEHA. No trace amounts of piperazine-containing isomers or branched (U) -PEHA isomers were found. From a commercial point of view, it is very attractive to have high selectivity and yield of L-PEHA without producing large amounts of high molecular weight alkylene amine homologs. The reaction scheme is as follows.

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

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

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

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

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

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

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

To investigate the effect of cyclic urea groups on the selectivity of the reaction with EDC, experiments were performed 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 aqueous solution) at 100℃for 30 minutes, respectively. The reaction mixture was then treated with 50wt% 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. =undetected

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

Claims

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

I is a kind of

-reacting said alkylene amine hydrohalate with an inorganic base to form an alkylene amine compound comprising at least one cyclic alkylene urea group of formula I; and

-A CO ₂ removal step comprising converting said alkylene amine comprising at least one cyclic alkylene urea group of formula I to the corresponding alkylene amine with CO ₂ removal, wherein this step is performed simultaneously with or subsequent to the step of reacting the alkylene amine hydrochloride with the inorganic base.

2. The method according to claim 1, wherein a is a C2 to C3 alkylene unit, optionally substituted with one or two C1 alkyl groups.

3. The method according to claim 1, wherein a is selected from the group consisting of ethylene, propylene and isopropylene.

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 II:

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

Wherein the method comprises the steps of

N (A) (CO) N-represents the structure of formula I,

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

A has the meaning as defined in any one of claims 1 to 3,

P is an integer of 0 to 8, and

Q is an integer from 0 to 8.

5. A process according to any one of claims 1 to 3, 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 method comprises the steps of

N (A) (CO) N-represents the structure of formula I,

A has the meaning as defined in any one of claims 1 to 3,

P is an integer of 0 to 8, and

Q is an integer from 0 to 8.

6. A process according to any one of claims 1 to 3 wherein the alkyl halide compound is an alkyl chloride compound.

7. A process according to any one of claims 1 to 3 wherein the alkyl halide compound selected from haloalkanes having 2 to 6 halogen atoms is selected from 1,2, 3-trichloropropane or C2 to C10 dihaloalkanes.

8. A process according to any one of claims 1 to 3, wherein the alkyl halide compound selected from haloalkanes having 2 to 6 halogen atoms is selected from 1, 1-dichloroethane, 1, 2-dichloropropane or 1, 3-dichloropropane.

9. A process according to any one of claims 1 to 3 wherein the alkyl halide compound is selected from haloaminoalkanes.

10. A process according to any one of claims 1 to 3, wherein the alkyl halide compound is selected from C2-C10 alkanes substituted with one or more halogen atoms and one or more amino groups.

11. A process according to any one of claims 1 to 3, wherein the alkyl halide compound is selected from 1-chloro-2-amino-ethane, 1-chloro-3-aminopropane, 1-chloro-2-aminopropane or the respective hydrochloride salt thereof.

12. A process according to any one of claims 1 to 3, wherein the step of reacting the alkylene amine hydrohalate with an inorganic 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.

13. The process according to claim 12, wherein the strong inorganic base is NaOH or KOH.

14. A process according to any one of claims 1 to 3 wherein the cyclic alkylene urea product formed in the process is a compound of formula V or a compound of formula VI:

V (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

VI (VI)

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

Wherein the method comprises the steps of

N (A) (CO) N-represents the structure of formula I,

The meaning of any of claims 1-3, p is an integer from 0 to 8, q is an integer from 0 to 8, and R1 is an alkylene chain from the alkyl halide compound, having 2-10 carbon atoms.

15. The process according to claim 1, wherein the urea adduct of diethylenetriamine is reacted with dichloroethane to form the biurea adduct of pentaethylenehexamine.

16. A process according to any one of claims 1 to 3 wherein the CO ₂ removal step is carried out by venting the reaction vessel with a stripping gas.

17. A process according to any one of claims 1 to 3 wherein the reaction medium comprises one or more of an alkylene urea compound, an alkyl halide compound selected from polyhalogenated alkanes or aminoalkyl alkanes, and ammonia and other alkylene amine compounds selected from alkylene amines of formula H ₂N-[AX-]_xA-NH₂, wherein X is an integer from 0 to 8, compounds of formula Y- [ a-X- ] _xA-NH₂, wherein Y is a piperazine ring and X is an integer from 0 to 8, and piperazine.

18. The method according to claim 17, wherein said alkyl halide compound is dichloroethane, and said other alkylene amine compound, if present, is selected from the group consisting of ethylene amines of formula H ₂N-[CH2-CH2-NH-]_x-CH2-CH2-NH₂, wherein x is an integer from 0 to 8, compounds of formula Y- [ CH2-NH- ] _x-CH2-CH2-NH₂, wherein Y is a piperazine ring and x is an integer from 0 to 8, and piperazine.

19. The method according to claim 18, wherein the additional alkylene amine compound is selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine, and piperazine.

20. A process according to any one of claims 1 to 3, wherein the process comprises the step of reacting an alkylene amine compound having a linear-NH-a-NH-group with a carbonyl transfer agent to produce an alkylene urea compound comprising at least one primary amine group and at least one cyclic alkylene urea group of formula I.