One-step catalytic synthesis of cyclic urea derivatives

Abstract

A process for the preparation of cyclic urea derivatives by reacting alkylene carbonates with primary amines in the presence of a metal oxide catalyst to form cyclic urea derivatives.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 439,899, filed January 19, 2023. The above-mentioned application is incorporated herein by reference.

[0002] The present disclosure relates generally to processes for preparing cyclic urea derivatives from alkylene carbonates and primary amines in the presence of a metal oxide catalyst, and their subsequent use in a variety of applications, such as in lithium ion battery manufacturing, for removing paints and coatings, and as solvents in compositions useful in the electronics, automotive, agricultural, and pharmaceutical industries. [Background technology]

[0003] N-methyl-2-pyrrolidone (NMP) has been widely used in various industries, particularly in the semiconductor, battery, and other electronics industries. NMP is a polar organic chemical with a unique combination of properties, such as low vapor pressure, a relatively high flash point, a low freezing point, and a high boiling point. NMP's molecular structure provides a special combination of dispersibility, polarity, and hydrogen bonding power, which enables its unique solvency for MNPs. However, the European Chemicals Agency (ECHA) has classified NMP as a "Substance of Very High Concern" due to its reproductive toxicity. Therefore, there is an urgent need to replace NMP with a less toxic alternative that has similar performance characteristics.

[0004] One potential alternative is cyclic urea derivatives. Various processes for producing such derivatives are known, such as reacting carbon dioxide in the presence of (i) an oxide of an element of main group III or IV or subgroup II to VI of the periodic table, (ii) a mixture thereof, or (iii) aluminum silicate or magnesium silicate (see Patent Document 1); reacting ethylene carbonate with a primary amine, which does not require the use of a solvent or catalyst (see Patent Document 2); and reacting an alkylene oxide with at least one of the following at a temperature of 50° C. or higher: (i) carbon dioxide and a monoalkylamine, (ii) a carbon dioxide compound of a monoalkylamine, and (iii) a 1,3-dialkylurea. However, problems associated with the known processes include, for example, harsh process conditions, long process times, the production of unwanted by-products, and low yields of cyclic urea derivatives.

[0005] Therefore, there is a need to develop a relatively simple and efficient process for the preparation of cyclic urea derivatives that does not suffer from the shortcomings of the prior art processes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 4,897,480 [Patent Document 2] U.S. Patent No. 5,783,706 Summary of the Invention

[0007] The present disclosure generally provides a process for preparing cyclic urea derivatives having the general formula:

[0008] [ka]

[0009] wherein R1 and R2 are independently (a) hydrogen, (b) a linear, branched, or cyclic alkyl radical having 1 to 12 carbon atoms, the radical being C6-C 10 (c) C-C, which may be optionally substituted with aryl, F, Cl, or Br; 10 Aryl radical, this radical is C1-C 12 (d) heteroalkyl radicals, in which the alkyl radical is as defined in (b) and is interrupted by one or more heteroatoms selected from O, S, and N; and (e) heteroaryl radicals having 5 to 10 ring atoms and containing 1 to 3 heteroatoms selected from O, S, and N; and R3 and R4 are independently selected from (a) straight-chain, branched, or cyclic alkyl radicals having 1 to 12 carbon atoms, which radical is selected from C6-C 10 (b) C-C, which may be optionally substituted with aryl, F, Cl, or Br; 10 Aryl radical, this radical is C1-C 12 (c) heteroalkyl radicals, which may be optionally substituted with alkyl, wherein the alkyl radical is as defined in (a) and is interrupted by one or more heteroatoms selected from O, S, and N, and (d) heteroaryl radicals, which have 5 to 10 ring atoms and contain 1 to 3 heteroatoms selected from O, S, and N. The process generally involves reacting an alkylene carbonate with a primary amine in the presence of a metal oxide catalyst to form a reaction product that includes a cyclic urea derivative.

[0010] The cyclic urea derivatives produced according to the processes of the present disclosure can be used in a variety of applications, for example, in the manufacture of lithium ion batteries, to remove paints and coatings, and as solvents in compositions useful in the electronics, automotive, agricultural, and pharmaceutical industries. DETAILED DESCRIPTION OF THE INVENTION

[0011] Before describing aspects of the present disclosure in detail, it is to be understood that the present disclosure is not limited in its application to the details of construction and arrangement of components or steps or methodologies set forth in the following description. The present disclosure is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

[0012] Unless otherwise defined herein, technical terms used in connection with this disclosure shall have the meanings that are commonly understood by those of ordinary skill in the art. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

[0013] As used in accordance with the present disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings:

[0014] The use of the words "a" or "an" means "comprising" or "including" When used in conjunction with the terms "including," "having," or "containing" (or variations of such terms), it can mean "one," but is also consistent with the meanings of "one or more," "at least one," and "one or more than one."

[0015] Use of the term "or" is used to mean "and / or," unless expressly stated to refer only to alternatives and only where the alternatives are mutually exclusive.

[0016] When "may," "can," "could," or "might" is used in this specification to describe that a certain element or feature is included or has a certain characteristic, it does not require that the particular element or feature be included or have the certain characteristic.

[0017] Throughout this disclosure, the term "about" is used to indicate that a value includes the inherent variation of error of a quantification device, mechanism, or method, or includes the inherent variation that exists between the subject(s) being measured. By way of example, and not limitation, when the term "about" is used, the specified value to which the term refers can vary by plus or minus 10%, or 9%, or 8%, or 7%, or 6%, or 5%, or 4%, or 3%, or 2%, or 1%, or one or more fractions therebetween.

[0018] As used herein, the words "comprising" (and any of its forms, e.g., "comprise" and "comprises"), "having" (and any of its forms, e.g., "have" and "has"), "including" (and any of its forms, e.g., "includes" and "include"), or "containing" (and any of its forms, e.g., "contains" and "contain") are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0019] Phrases such as "in one embodiment," "in an embodiment," "according to one embodiment," and the like generally mean that the particular feature, structure, or characteristic that follows the phrase is included in at least one embodiment of the present disclosure, and may be included in more than one embodiment of the present disclosure. Importantly, such phrases are open-ended and do not necessarily refer to the same embodiment, but rather, of course, can refer to one or more prior and / or subsequent embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0020] In the processes described herein, steps may be performed in any order without departing from the principles of the invention, except where a temporal or operational order is expressly stated.

[0021] Furthermore, specified steps may be performed simultaneously unless the claim language clearly dictates that they be performed separately. For example, a claimed step of performing X and a claimed step of performing Y may be performed simultaneously in a single operation, and the resulting process would fall within the literal scope of the claimed process.

[0022] Values ​​expressed in range format should be interpreted in an open manner, not only to include the numbers specified as the limits of the range, but also to include all individual numbers or subranges subsumed within the range, as if each number and subrange were specifically stated. For example, 1 to A range such as 6 should be considered to specifically disclose subranges of 1 to 3, 2 to 4, 3 to 6, etc., as well as individual numbers subsumed within that range, for example, 1, 2, 3, 4, 5, and 6. This is true regardless of the breadth of the range.

[0023] The terms "preferred" and "preferably" refer to embodiments that may offer certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or different circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the present disclosure.

[0024] The term "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances when the event or circumstance occurs and instances when it does not occur.

[0025] The present disclosure generally relates to a process for preparing cyclic urea derivatives having the general formula:

[0026] [ka]

[0027] wherein R1 and R2 are independently (a) hydrogen, (b) a linear, branched, or cyclic alkyl radical having 1 to 12 carbon atoms, the radical being C6-C 10 (c) C-C, which may be optionally substituted with aryl, F, Cl, or Br; 10 Aryl radical, this radical is C1-C 12 (d) heteroalkyl radicals, in which the alkyl radical is as defined in (b) and is interrupted by one or more heteroatoms selected from O, S, and N; and (e) heteroaryl radicals having 5 to 10 ring atoms and containing 1 to 3 heteroatoms selected from O, S, and N; and R3 and R4 are independently selected from (a) straight-chain, branched, or cyclic alkyl radicals having 1 to 12 carbon atoms, which radical is selected from C6-C 10 (b) C-C, which may be optionally substituted with aryl, F, Cl, or Br; 10 Aryl radical, this radical is C1-C 12 (c) heteroalkyl radicals, in which the alkyl radical is as defined in (a) and is interrupted by one or more heteroatoms selected from O, S, and N; and (d) heteroaryl radicals having 5 to 10 ring atoms, in which the ring atoms contain 1 to 3 heteroatoms selected from O, S, and N; The process comprises reacting an alkylene carbonate with a primary amine in the presence of a metal oxide catalyst to form a reaction product comprising a cyclic urea derivative.

[0028] According to one embodiment, the alkylene carbonate is a compound having the following formula (I):

[0029] [ka]

[0030] In the formula, R a and R b are independently hydrogen, hydroxymethyl, straight or branched chain C1-C 18 alkyl, aryl, or alkylaryl groups, in which the benzene ring is C1-C 18 It is substituted with an alkyl group.

[0031] In further embodiments, the alkylene carbonate used in the present disclosure is represented by the formula I above, R a and R b are independently hydrogen, methyl, ethyl, propyl, or hydroxymethyl. The most preferred alkylene carbonates are those in which R a and R b are hydrogen (ethylene carbonate), methyl (propylene carbonate), and ethyl (butylene carbonate).

[0032] The following are examples of alkylene carbonates that may be used in this disclosure, including mixtures thereof: 1,3-dioxolan-2-one (also known as ethylene carbonate); 4-methyl-1,3-dioxolan-2-one (also known as propylene carbonate); 4-hydroxymethyl-1,3-dioxolan-2-one; 4,5-dimethyl-1,3-dioxolan-2-one; 4-ethyl-1,3-dioxolan-2-one; 4,4-dimethyl-1,3-dioxolan-2-one (the first three are also known as butylene carbonate); 4-methyl-5-ethyl-1,3-dioxolan-2-one; 4,5-diethyl-1,3-dioxolan- 2-one; 4,4-diethyl-1,3-dioxolan-2-one; 1,3-dioxan-2-one; 4,4-dimethyl-1,3-dioxan-2-one; 5,5-dimethyl-1,3-dioxan-2-one; 5,5-dihydroxymethyl-1,3-dioxan-2-one; 5-methyl-1,3-dioxan-2-one; 4-methyl-1,3-dioxan-2-one; 5-hydroxy-1,3-dioxan-2-one; 5-hydroxymethyl-5-methyl-1,3-dioxan-2-one; 5,5-diethyl-1,3-dioxan-2-one; and 5-methyl-5-propyl-1,3-dioxan-2-one.

[0033] In one embodiment, the primary amine reacted with the alkylene carbonate is a compound having the following formula (II): R-NH2(II) wherein R is (a) a linear, branched, or cyclic alkyl radical having 1 to 12 carbon atoms, the radical being C6-C 10 Optional substitution by aryl, F, Cl, Br is possible; (b) C6-C 10 Aryl radical, this radical is C1-C 12Optional substitution by alkyl is possible; (c) heteroalkyl radicals, in which the alkyl radical is as defined in (a) and is interrupted by one or more heteroatoms selected from O, S, and N; and (d) heteroaryl radicals having 5 to 10 ring atoms, the ring atoms of which contain 1 to 3 heteroatoms selected from O, S, and N.

[0034] Examples of primary amines include, but are not limited to, methylamine, ethylamine, propylamine, butylamine, heptylamine, hexylamine, cyclopropylamine, cyclohexylamine, cycloheptylamine, cyclooctylamine, aniline, N-methylaniline, N,N-dimethylaniline, m-toluidine, o-chloroaniline, 3,5-dimethylaniline, o-anisidine, 2,5-dichloroaniline, 2,4,6-trichloroaniline, 3,4-dichloroaniline, benzylamine, and mixtures thereof.

[0035] In one embodiment, the primary amine is preferably a monoalkylamine in which the alkyl group has 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and especially methylamine.

[0036] The reaction of the alkylene carbonate with the primary amine occurs in the presence of a metal oxide catalyst. In one embodiment, the metal oxide catalyst is an alkali oxide or alkaline earth oxide, such as lithium oxide, sodium oxide, potassium oxide, cesium oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, rubidium oxide, and mixtures thereof. In another embodiment, the metal oxide catalyst is an alkali oxide catalyst including lithium oxide, sodium oxide, potassium oxide, cesium oxide, and mixtures thereof. In yet another embodiment, the metal oxide catalyst is cesium oxide.

[0037] The reaction of the alkylene carbonate with the primary amine can occur with or without a solvent that does not participate in the reaction. In one embodiment, the solvent is water, and the water can be present in an amount of up to about 50% by weight, based on the total weight of the alkylene carbonate. In another embodiment, the amount of water present is from about 30% to about 45% by weight, based on the total weight of the alkylene carbonate.

[0038] In some embodiments, the molar ratio of alkylene carbonate to primary amine (alkylene carbonate:primary amine) present in the reaction can be up to about 1:5, e.g., from about 0.5:2.5 to about 1:2, or from about 0.8:1 to about 1:1.5, or from about 0.9:1 to about 1.1:1. In other embodiments, the molar ratio of alkylene carbonate to primary amine present in the reaction can be from about 0.95:1 to about 1.05:1, or from about 0.97:1 to about 1.03:1, or from about 0.99:1 to about 1.01:1. The order in which the alkylene carbonate and primary amine are added as raw materials is not particularly limited; the alkylene carbonate can be added to the primary amine, or the primary amine can be added to the alkylene carbonate, or the primary amine and alkylene carbonate can be added simultaneously.

[0039] In one embodiment, the amount of metal oxide catalyst used in the reaction can be less than about 5 wt%, or less than about 3 wt%, or less than about 2 wt%, or less than about 1.5 wt%, or less than about 1 wt%, or less than about 0.5 wt%, based on the total weight of alkylene carbonate. In other embodiments, the amount of metal oxide catalyst used in the reaction can be from about 0.1 wt% to about 5 wt%, or from about 0.5 wt% to about 2.5 wt%, or from about 0.8 wt% to about 2 wt%, based on the total weight of alkylene carbonate.

[0040] In some embodiments, the reaction of the alkylene carbonate with the primary amine can occur at a temperature of about 180°C to about 300°C, or about 220°C to about 260°C, or about 245°C to about 255°C. The reaction of the alkylene carbonate with the primary amine can occur under elevated or reduced pressure, but is preferably carried out at atmospheric pressure. The reaction can take from about 0.5 hours to about 24 hours, or from about 1 hour to about 10 hours, or from about 2 hours to about 5 hours to complete. In addition to the desired cyclic urea derivative, one or more by-products may be present in the resulting reaction product (e.g., one or more by-products such as glycol, piperazine, and urea, unreacted primary amine, unreacted alkylene carbonate, and other impurities). The cyclic urea derivative can be purified by isolating at least a portion of the by-product(s) and subjecting the reaction product to a separation technique, such as concentration, crystallization, recrystallization, distillation, fractional distillation, or chromatographic techniques.

[0041] The percent yield of cyclic urea derivatives obtained by the processes of the present disclosure (i.e., 100×([actual amount of cyclic urea derivative (e.g., by gas chromatography)] / [maximum amount of cyclic urea derivative producible from a given amount of alkylene carbonate and primary amine])) can be at least about 65%, or at least about 70%, or at least about 80%, or at least about 85%. Specific examples of cyclic urea derivatives producible by the processes of the present disclosure include, but are not limited to, 1,3-dimethyl-2-imidazolidinone, 1,3,4-trimethyl-2-imidazolidinone, and 1,3-dipropyl-2-imidazolidinone.

[0042] The cyclic urea derivatives obtained by the process of the present disclosure can be used in various ways, for example, in the preparation of lithium ion batteries, as photochemical reaction solvents, as solvents for photoelectrochemical display elements, in electrolyte solvents, in battery electrolyte solvents, as solvents for electrolytic reactions, as solvents for electropolymerization, as solvents for electroplating, as solvents for electropolishing, as solvents for cleaning semiconductor wafer surfaces and removing photoresist layer(s), as aprotic polar solvents in organic synthesis reactions, as solvents for polymerization or extraction, as low toxicity high boiling point solvents, as industrial cleaners, as solvents for stripping or removing paint or coating films, as textile finishes, and as solvents in the manufacture of automotive part cleaning formulations or pharmaceutical or agrochemical formulations.

[0043] The following examples of the present invention's process for preparing cyclic urea derivatives are presented.However, it should be understood that the present disclosure is not limited in its application to the specific experiments, results, and experimental procedures disclosed herein below.Instead, the examples are provided as only one of various embodiments, and are meant to be illustrative and not exhaustive. [Example]

[0044] Example 1 - Preparation process of 1,3-dimethyl-2-imidazolidinone without catalyst A 1 L autoclave reactor was equipped with an agitator, nitrogen line, and feed lines, purged with nitrogen, and charged with 250 grams of ethylene carbonate, 100 grams of DI water, and 250 grams of monomethylamine. The reactor was gradually heated to a temperature of about 250°C over a period of about 30 minutes, and then the temperature was maintained at 250°C for about 24 hours. The reactor was then cooled to room temperature, and the resulting reaction product was bottled in a nitrogen-filled 32 oz. bottle for final release. The reaction product was characterized (by gas chromatography) to contain 1,3-dimethyl-2-imidazolidinone in about 74% yield and by-products, including, but not limited to, dimethylpiperazine, trimethylethanediamine, tetramethylethanediamine, and ethylene glycol.

[0045] Example 2 - Preparation process of 1,3-dimethyl-2-imidazolidinone using metal oxide catalyst A 1 L autoclave reactor was equipped with an agitator, nitrogen line, and feed lines, the reactor was purged with nitrogen, and the reactor was charged with 250 grams of ethylene carbonate, 100 grams of DI water, 5 grams of cesium oxide, and 250 grams of monomethylamine. The reactor was gradually heated to a temperature of about 250°C over a period of about 30 minutes, and then the temperature was maintained at 250°C for about 24 hours. The reactor was then cooled to room temperature, and the resulting reaction product was transferred to a 32 oz. nitrogen-filled flask. The reaction mixture was bottled and finished. The product was then characterized (by gas chromatography) and found to contain 1,3-dimethyl-2-imidazolidinone in approximately 88% yield, as well as by-products, including but not limited to dimethylpiperazine. When a metal oxide catalyst was used, the amount of impurities was significantly reduced compared to Example 1.

[0046] Example 3 - Preparation process of 1,3-dimethyl-2-imidazolidinone using metal oxide catalyst A 1 L autoclave reactor was equipped with an agitator, nitrogen line, and feed lines, purged with nitrogen, and charged with 250 grams of ethylene carbonate, 100 grams of DI water, 5 grams of cesium oxide, and 250 grams of monomethylamine. The reactor was gradually heated to a temperature of about 180°C over about 30 minutes, and then the temperature was maintained at 180°C for about 24 hours. The reactor was then cooled to room temperature, and the resulting reaction product was bottled in a nitrogen-filled 32 oz. bottle for final release. The reaction product was then characterized (by gas chromatography) to contain 1,3-dimethyl-2-imidazolidinone in about 24% yield and by-products, including, but not limited to, ethylene glycol (about 41% yield) and dimethylurea (about 34% yield).

[0047] Example 4 - Preparation process of 1,3-dimethyl-2-imidazolidinone using metal oxide catalyst A 1 L autoclave reactor was equipped with an agitator, nitrogen line, and feed lines, purged with nitrogen, and charged with 250 grams of ethylene carbonate, 100 grams of DI water, 5 grams of cesium oxide, and 250 grams of monomethylamine. The reactor was gradually heated to a temperature of about 220°C over a period of about 30 minutes, and then the temperature was maintained at 220°C for about 24 hours. The reactor was then cooled to room temperature, and the resulting reaction product was bottled in a nitrogen-filled 32 oz. bottle for final release. The reaction product was then characterized (by gas chromatography) to contain 1,3-dimethyl-2-imidazolidinone in about 70% yield, and by-products, including, but not limited to, ethylene glycol and dimethylurea.

[0048] Example 5 - Preparation process of 1,3,4-trimethyl-2-imidazolidinone without catalyst A 1 L autoclave reactor was equipped with an agitator, nitrogen line, and feed lines, purged with nitrogen, and charged with 250 grams of propylene carbonate, 86 grams of DI water, and 216 grams of monomethylamine. The reactor was gradually heated to a temperature of about 250°C over a period of about 30 minutes, and then the temperature was maintained at 250°C for about 24 hours. The reactor was then cooled to room temperature, and the resulting reaction product was bottled in a nitrogen-filled 32 oz. bottle for final release. The reaction product was then characterized (by gas chromatography) to include 1,3,4-trimethyl-2-imidazolidinone in about 10.5% yield and by-products, including but not limited to propylene glycol (about 83% yield).

[0049] Example 6 - Preparation process of 1,3,4-trimethyl-2-imidazolidinone using metal oxide catalyst A 1 L autoclave reactor was equipped with an agitator, nitrogen line, and feed lines, purged with nitrogen, and charged with 250 grams of propylene carbonate, 86 grams of DI water, 5 grams of cesium oxide, and 216 grams of monomethylamine. The reactor was gradually heated to a temperature of about 250°C over a period of about 30 minutes, and then the temperature was maintained at 250°C for about 24 hours. The reactor was then cooled to room temperature, and the resulting reaction product was bottled in a nitrogen-filled 32 oz. bottle for final release. The reaction product was then characterized (by gas chromatography) to contain 1,3,4-trimethyl-2-imidazolidinone in about 48% yield and by-products, including but not limited to propylene glycol (about 32%).

[0050] From the foregoing disclosure, it is evident that the present disclosure is well adapted to carry out the objects and obtain the advantages mentioned herein as well as those inherent therein. While illustrative embodiments of the present disclosure have been described for purposes of disclosure, it will be understood that numerous modifications can be made, and will be readily suggested to those skilled in the art, which modifications can be effected without departing from the scope of the disclosure and the appended claims.

Claims

1. 1. A process for the preparation of cyclic urea derivatives having the general formula: 【Chemistry 1】 In the formula, R １ and R ２ are independently (a) hydrogen, (b) a straight-chain, branched-chain, or cyclic alkyl radical having 1 to 12 carbon atoms, which radical is C ６ -C １０ (c) C can be optionally substituted with aryl, F, Cl, or Br; ６ -C １０ Aryl radicals, which radicals are C １ -C １２ (d) heteroalkyl radicals, wherein the alkyl radical is as defined in (b) and is interrupted by one or more heteroatoms selected from O, S, and N; and (e) heteroaryl radicals having 5 to 10 ring atoms, wherein the ring atoms contain 1 to 3 heteroatoms selected from O, S, and N; and R ３ and R ４ are independently (a) a straight-chain, branched-chain, or cyclic alkyl radical having 1 to 12 carbon atoms, the radical being C ６ -C １０ (b) C, which may be optionally substituted with aryl, F, Cl, or Br; ６ -C １０ Aryl radicals, which radicals are C １ -C １２ (c) heteroalkyl radicals, wherein the alkyl radical is as defined in (a) and is interrupted by one or more heteroatoms selected from O, S, and N; and (d) heteroaryl radicals having 5 to 10 ring atoms, the ring atoms of which contain 1 to 3 heteroatoms selected from O, S, and N; The process comprises reacting an alkylene carbonate with a primary amine in the presence of a metal oxide catalyst to form a reaction product comprising the cyclic urea derivative. The process.

2. The alkylene carbonate is a compound having the following formula (I): 【Chemistry 2】 In the formula, R ａ and R ｂ , independently hydrogen, hydroxymethyl, straight or branched chain C １ -C １８ alkyl group, aryl group, or alkylaryl group, and among these groups, the benzene Ring is C １ -C １８ The process of claim 1 wherein the alkyl group is substituted.

3. R ａ and R ｂ is independently hydrogen, methyl, ethyl, or propyl.

4. R ａ and R ｂ The process of claim 3 , wherein is hydrogen or methyl.

5. The primary amine is a compound having the following formula (II): R-NH ２ (II) wherein R is (a) a straight-chain, branched-chain, or cyclic alkyl radical having 1 to 12 carbon atoms; ６ -C １０ Optional substitution by aryl, F, Cl, Br is possible; (b) C ６ -C １０ Aryl radicals, which radicals are C １ -C １２ (c) heteroalkyl radicals, wherein the alkyl radical is as defined in (a) and is interrupted by one or more heteroatoms selected from O, S, and N; and (d) heteroaryl radicals having 5 to 10 ring atoms, the ring atoms containing 1 to 3 heteroatoms selected from O, S, and N.

10. The process of claim 1.

6. 6. The process of claim 5, wherein the primary amine is methylamine, ethylamine, propylamine, butylamine, heptylamine, hexylamine, cyclopropylamine, cyclohexylamine, cycloheptylamine, cyclooctylamine, aniline, N-methylaniline, N,N-dimethylaniline, m-toluidine, o-chloroaniline, 3,5-dimethylaniline, o-anisidine, 2,5-dichloroaniline, 2,4,6-trichloroaniline, 3,4-dichloroaniline, or benzylamine.

7. 7. The process of claim 6, wherein the primary amine comprises methylamine.

8. 10. The process of claim 1, wherein the metal oxide catalyst comprises an alkali oxide or an alkaline earth oxide.

9. 9. The process of claim 8, wherein the metal oxide catalyst comprises lithium oxide, sodium oxide, potassium oxide, cesium oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, rubidium oxide, and mixtures thereof.

10. 10. The process of claim 9, wherein the metal oxide catalyst comprises potassium oxide, cesium oxide, or rubidium oxide.

11. 1. A process for preparing a cyclic urea derivative, comprising reacting an alkylene carbonate with a primary amine in the presence of an alkali metal oxide catalyst and a solvent to form a reaction product comprising the cyclic urea derivative and one or more by-products; and optionally subjecting the reaction product to a separation technique to remove at least a portion of the one or more by-products.

12. 12. The process of claim 11, wherein the alkylene carbonate and the primary amine are present in the reaction in a molar ratio of alkylene carbonate:primary amine of from about 0.5:2.5 to about 1:

2.

13. 12. The process of claim 11, wherein the amount of the alkali metal oxide catalyst present in the reaction is from about 0.1% to about 5% by weight, based on the total weight of the alkylene carbonate.

14. The process of claim 11 , wherein the solvent comprises water.

15. 15. The process of claim 14, wherein the water is present in an amount up to about 50% by weight, based on the total weight of the alkylene carbonate.

16. 12. The process of claim 11, wherein the reaction occurs at a temperature of about 245°C to about 255°C.

17. 12. The process of claim 11, wherein the separation technique is concentration, crystallization, recrystallization, distillation, fractional distillation, or a chromatographic technique.

18. 12. The process of claim 11, wherein the cyclic urea derivative is 1,3-dimethyl-2-imidazolidinone.

19. 19. The process of claim 18, wherein the 1,3-dimethyl-2-imidazolidinone is present in the reaction product in a percent yield of at least 80%.

Images