AN N,N-DIHYDROCARBONYLAMIDE CARBOXYLIC ACID, PREPARATION METHOD THEREFOR AND USE THEREOF

Abstract

The present invention provides an N,N-dihydrocarbonyl amide carboxylic acid, preparation method therefor and use thereof. The N,N-dihydrocarbonyl amide carboxylic acid can be used as an extractant for enriching rare earth elements from raw materials containing low-concentration rare earth elements, separating and purifying yttrium element from mixed rare earth raw material, and separating elements such as aluminum, iron, radioactive thorium, radioactive uranium and actinide from mixed rare earth raw material, etc. The compound can be synthesized in a simple and cost-efficient way. As an extractant, it has good chemical stability and can withstand strong acid and strong alkali without decomposition.

Claims

1. An N,N-dihydrocarbonyl amide carboxylic acid with a structure represented by Formula I: ##STR00051## wherein, R.sub.1 and R.sub.2 are each independently a linear or branched, saturated or unsaturated, and substituted or unsubstituted C6 or more hydrocarbonyl; R.sub.3 is a linear or branched, saturated or unsaturated, and substituted or unsubstituted hydrocarbonyl; n is a natural number from 1 to 10.

2. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.1 and R.sub.2 are each independently a linear or branched, saturated or unsaturated, and substituted or unsubstituted C6-C30 hydrocarbonyl.

3. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.1 and R.sub.2 are each independently a linear or branched, saturated or unsaturated, and unsubstituted C6 or more hydrocarbonyl.

4. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.1 and R.sub.2 are each independently a linear or branched and unsubstituted C6-C30 alkyl.

5. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein n is a natural number from 1 to 6.

6. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein R.sub.1 and R.sub.2 are independently ##STR00052## wherein 2≤a+b≤10, represents a connecting site.

7. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein R.sub.1 and R.sub.2 are independently any one selected from the group consisting of the following groups, wherein represents a connecting site, ##STR00053## ##STR00054##

8. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.3 is selected from a linear or branched, saturated or unsaturated, and substituted or unsubstituted C6 or more hydrocarbonyl.

9. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.3 is selected from a linear or branched, unsaturated, and unsubstituted C6 or more hydrocarbonyl.

10. The N,N-dihydrocarbonyl amide carboxylic acid according of claim 1, wherein R.sub.3 is any one selected from the group consisting of the following groups, wherein represents a connecting site, ##STR00055## ##STR00056##

11. A method for preparing the N,N-dihydrocarbonyl amide carboxylic acid according to claim 1 comprising a step of: mixing and reacting an N,N-dihydrocarbonyl secondary amine represented by Formula II and an anhydride compound represented by Formula III to obtain the N,N-dihydrocarbonyl amide carboxylic acid represented by Formula I, as shown in the following Reaction Scheme: ##STR00057## or mixing and reacting the N,N-dihydrocarbonyl secondary amine represented by Formula II and a carboxylic acid-monoacyl chloride compound represented by Formula IV to obtain the N,N-dihydrocarbonyl amide carboxylic acid represented by Formula I, as shown in the following Reaction Scheme: ##STR00058##

12. The method for preparing the N,N-dihydrocarbonyl amide carboxylic acid according to claim 11, wherein a molar ratio between the N,N-dihydrocarbonyl secondary amine represented by Formula II and the anhydride compound represented by Formula III is 1:(0.8-1.2); or , the molar ratio of the N,N-dihydrocarbonyl secondary amine represented by Formula II and the carboxylic acid-mono acyl chloride compound represented by Formula IV is 1:(0.8-1.2).

13. The method for preparing the N,N-dihydrocarbonyl amide carboxylic acid according to claim 11, wherein the N,N-dihydrocarbonyl secondary amine represented by Formula II and the anhydride compound represented by Formula III are mixed and reacted at a temperature of 0° C. to 125° C. for 0.5 to 4 hours; or the N,N-dihydrocarbonyl secondary amine represented by Formula II and the carboxylic acid-mono acyl chloride compound represented by Formula IV are mixed and reacted at temperature of 0° C. to 125° C. for 0.5 to 4 hours.

14. The method for preparing the N,N-dihydrocarbonyl amide carboxylic acid according to claim 11, wherein the N,N-dihydrocarbonyl secondary amine represented by Formula II and the anhydride compound represented by Formula III are mixed and reacted in the absence of a solvent or in a solvent; or the N,N-dihydrocarbonyl secondary amine represented by Formula II and the carboxylic acid-monoacyl chloride compound represented by Formula IV are mixed and reacted in the absence of a solvent or in a solvent; and when mixed in the solvent, the solvent is an inert solvent and selected from any one or a combination of at least two selected from the group consisting of hexane, dichloromethane, petroleum ether, toluene, xylene or kerosene.

15. Use of the N,N-dihydrocarbonyl amide carboxylic acid according to claim 1 in preparing an extractant for separating rare earth elements.

16. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.1 and R.sub.2 are each independently a linear or branched, saturated or unsaturated, and substituted or unsubstituted C6-C18 hydrocarbonyl.

17. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.1 and R.sub.2 are each independently a branched, saturated or unsaturated, and unsubstituted C6-C30 hydrocarbonyl.

18. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.1 and R.sub.2 are each independently a branched, saturated or unsaturated, and unsubstituted C6-C10 hydrocarbonyl.

19. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.1 and R.sub.2 are each independently a linear or branched and unsubstituted C6-C18 alkyl.

20. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.1 and R.sub.2 are each independently a linear or branched and unsubstituted C6-C10 alkyl.

21. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.3 is selected from a linear or branched, saturated or unsaturated, and substituted or unsubstituted C6-C30 hydrocarbonyl.

22. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.3 is selected from a linear C10 or more alkenyl.

23. The N,N-dihydrocarbonyl amide carboxylic acid according to claim 1, wherein, R.sub.3 is selected from a linear C10-C18 alkenyl.

Description

BRIEF DESCRIPTION TO THE DRAWING

[0046] FIG. 1 is a proton nuclear magnetic resonance spectrum of N,N-dihydrocarbonyl amide carboxylic acid provided in Example 1.

[0047] FIG. 2 is a NMR Carbon spectrum of N,N-dihydrocarbonyl amide carboxylic acid provided in Example 1.

MODE OF CARRYING OUT THE INVENTION

[0048] In the following, the technical solution of the present invention will be further explained with reference to the drawings and specific embodiments. It should be understood to those skilled in the art that the detailed description is intended to aid in the understanding of the present invention, and should not be regarded as a specific limitation of the present invention.

Example 1

[0049] The present Example provides a compound I-1 represented by Formula I, which has a structural formula as follows:

##STR00008##

[0050] Compound I-1 was prepared by the synthesis route as follows:

##STR00009##

[0051] The synthesis method can be carried out with or without a solvent, and the synthesis method with a solvent was as follows:

[0052] (1) N,N-diisooctyl secondary amine (24.2 g, 0.10 mol) represented by Formula II-1 was dissolved in toluene (20 mL) to obtain solution 1; dodecenyl glutaric anhydride compound (26.7 g, 0.10 mol) represented by Formula III-1 was dissolved in toluene (30 mL) to obtain solution 2;

[0053] (2) the solution 1 was added into the solution 2, the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, the inert solvent was removed by concentrating in vacuum to obtain the compound I-1.

[0054] The synthesis method without a solvent was as follows:

[0055] N,N-dihydrocarbonyl secondary amine represented by Formula II-1 (24.2 g, 0.10 mol) and anhydride compound represented by Formula III-1 (28.2 g, 0.10 mol) were directly mixed to form a mixed solution, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, the compound I-1 was obtained.

[0056] Or N,N-dihydrocarbonyl secondary amine represented by Formula II-1 and carboxylic acid-monoacyl chloride compound represented by Formula III-1a were mixed and reacted, as shown in the following Reaction Scheme:

##STR00010##

[0057] The synthesis method was as follows: N,N-dihydrocarbonyl secondary amine represented by Formula II-1 (24.2 g, 0.10 mol) and carboxylic acid-monochloride compound represented by Formula III-1a (31.7 g, 0.10 mol) were directly mixed to form a mixed solution, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, compound I-1 was obtained.

[0058] In the present invention, the compound I-1 was analyzed by nuclear magnetic resonance, and the results were shown in FIGS. 1 and 2.

[0059] The analysis of NMR Hydrogen spectrum (FIG. 1) was as follows: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.06 (5H), 2.77 (2H), 1.95 (2H), 1.92 (2H), 1.84 (2H), 1.56 (4H), 1.33 (2H), 1.31 (8H), 1.29 (2H), 1.26 (12H), 1.17 (4H), 0.99 (6H), 0.81 (9H).

[0060] Among them, peaks at 0.81-1.95 were assigned to hydrogen of alkyl chain in compound I-1; peak at 2.77 was assigned to hydrogen of methylene in

##STR00011##

structure; peak at 3.06 was assigned to hydrogen of methylidyne in

##STR00012##

structure and hydrogen of methylene in

##STR00013##

structure; peaks at 4.91 and 5.21 were assigned to two hydrogens of olefin in

##STR00014##

structure; and peak at 10.58 was assigned to hydrogen of carboxyl.

[0061] The analysis of NMR carbon spectrum (FIG. 2) was as follows: .sup.13C NMR (500 MHz, CDCl.sub.3), δ 179.5, 172.1, 128.9, 128.3, 51.4 (2C), 36.7 (2C), 35.6, 33.0, 32.0 (2C), 31.9, 29.9, 30.2 (2C), 29.7, 29.7, 29.6, 29.6, 29.3 (2C), 29.3, 27.7, 27.3, 22.8 (2C), 22.8, 13.7 (2C), 13.7, 10.6 (2C).

[0062] Among them, peaks at 10.6-30.2 were assigned to carbon of alkyl chain in compound I-1; peaks at 35.6 and 36.7 were assigned to carbon of methylidyne in the

##STR00015##

structure; peak at 51.4 was assigned to carbon of methylene in

##STR00016##

structure; peak at 172.1 was assigned to carbon of amide carbonyl and peak at 179.5 was assigned to carbon of carboxyl.

Example 2

[0063] The present Example provides a compound I-2 represented by Formula I, which has a structural Formula as follows:

##STR00017##

[0064] Compound I-2 was prepared by the synthesis route as follows:

##STR00018##

[0065] (1) N,N-diisohexyl secondary amine represented by Formula II-2 (18.5 g, 0.10 mol) was dissolved in hexane (20 mL) to obtain solution 1; dodecenyl glutaric anhydride compound represented by Formula III-2 (26.7 g, 0.10 mol) was dissolved in hexane (30 mL) to obtain solution 2;

[0066] (2) the solution 1 was added into the solution 2, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, the inert solvent was removed by concentrating in vacuum to obtain compound I-2.

[0067] NMR characterization of compound I-2: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.12 (4H), 3.02 (1H), 2.33 (2H), 1.94 (2H), 1.92 (2H), 1.84 (2H), 1.33 (2H), 1.30 (4H), 1.29 (2H), 1.26 (8H), 1.20 (8H), 0.99 (12H), 0.88 (3H).

[0068] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 128.9, 128.3, 52.1 (2C), 39.7 (2C), 37.4, 33.0, 31.9, 29.9, 29.7, 29.7, 29.6, 29.6, 29.3, 27.7, 27.3, 25.7 (4C), 22.7, 14.1, 11.6 (4C).

Example 3

[0069] The present Example provides a compound I-3 represented by Formula I, which has a structural Formula as follows:

##STR00019##

[0070] Compound I-3 was prepared by the synthesis route as follows:

##STR00020##

[0071] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-3 (24.2 g, 0.10 mol) was dissolved in petroleum ether (20 mL) to obtain solution 1; dodecenyl glutaric anhydride compound represented by Formula III-3 (28.2 g, 0.10 mol) was dissolved in petroleum ether (30 mL) to obtain solution 2;

[0072] (2) the solution 1 was added into the solution 2, and the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, the inert solvent was removed by concentrating in vacuum to obtain compound I-3.

[0073] NMR characterization of compound I-3: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.25 (4H), 3.02 (1H), 2.37 (2H), 2.12 (2H), 1.94 (2H), 1.85 (2H), 1.33 (2H), 1.30 (4H), 1.29 (2H), 1.28 (4H), 1.26 (8H), 1.25 (4H), 1.24 (4H), 1.19 (4H), 0.93 (6H), 0.88 (6H), 0.87 (3H).

[0074] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.5, 170.1, 128.7, 128.1, 54.4 (2C), 37.4, 34.8 (2C), 33.0, 32.1 (2C), 31.9, 30.8 (2C), 29.9, 29.7, 29.7, 29.6, 29.6, 29.3, 27.7, 27.3, 26.5 (2C), 22.7 (2C), 22.7, 18.4 (2C), 14.1 (2C), 14.0.

Example 4

[0075] The present Example provides a compound I-4 represented by Formula I, which has a structural Formula as follows:

##STR00021##

[0076] Compound I-4 was prepared by the synthesis route as follows:

##STR00022##

[0077] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-4 (24.2 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; dodecenyl glutaric anhydride compound represented by Formula III-4 (28.2 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0078] (2) the solution 1 was added into the solution 2, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-4.

[0079] NMR characterization of compound I-4: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.18 (4H), 3.02 (1H), 2.33 (2H), 1.94 (2H), 1.84 (2H), 1.52 (4H), 1.33 (2H), 1.30 (2H), 1.30 (2H), 1.29 (2H), 1.29 (4H), 1.27 (4H), 1.26 (8H), 1.26 (4H), 1.26 (4H), 1.26 (4H), 0.88 (9H).

[0080] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 128.9, 128.3, 50.0 (2C), 37.4, 33.0, 31.9 (2C), 31.9, 29.9, 29.7, 29.7, 29.6, 29.6, 29.3, 29.3 (2C), 29.3 (2C), 29.3 (2C), 27.0 (2C), 22.7 (2C), 27.7, 27.3, 22.7, 14.1 (2C), 14.1.

Example 5

[0081] The present Example provides a compound I-5 represented by Formula I, which has a structural Formula as follows:

##STR00023##

[0082] Compound I-5 was prepared by the synthesis route as follows:

##STR00024##

[0083] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-5 (18.6 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; dodecenyl glutaric anhydride compound represented by Formula III-5 (28.0 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0084] (2) the solution 1 was added into the solution 2, and the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-5.

[0085] NMR characterization of compound I-5: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.18 (4H), 3.02 (1H), 2.33 (2H), 1.94 (2H), 1.84 (2H), 1.52 (4H), 1.33 (2H), 1.30 (2H), 1.30 (2H), 1.29 (2H), 1.29 (4H), 1.28 (4H), 1.28 (4H), 1.26 (8H), 0.88 (3H), 0.88 (6H).

[0086] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 128.9, 128.3, 50.0 (2C), 37.4, 33.0, 31.9, 31.5 (2C), 29.9, 29.7, 29.7, 29.6, 29.6, 29.3, 29.3 (2C), 27.7, 27.3, 26.7 (2C), 22.7 (2C), 22.7, 14.1 (2C), 14.1.

Example 6

[0087] The present Example provides a compound I-6 represented by Formula I, which has a structural Formula as follows:

##STR00025##

[0088] Compound I-6 was prepared by the synthesis route as follows:

##STR00026##

[0089] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-6 (23.8 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; dodecenyl glutaric anhydride compound represented by Formula III-6 (26.7 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0090] (2) the solution 1 was added into the solution 2, and the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-6.

[0091] NMR characterization of compound I-6: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 6.83 (2H), 5.21 (1H), 4.91 (1H), 3.02 (1H), 2.33 (2H), 2.18 (4H), 2.0 (4H), 1.94 (2H), 1.84 (2H), 1.33 (2H), 1.38 (4H), 1.30 (2H), 1.30 (2H), 1.29 (2H), 1.29 (4H), 1.26 (8H), 0.93 (6H), 0.88 (3H), 0.85 (6H).

[0092] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 165.7, 128.9, 128.3, 124.6 (2C), 116.6 (2C), 37.6, 33.0, 31.9, 29.9, 29.7, 29.7, 29.6, 29.6, 29.6 (2C), 29.3, 28.0 (2C), 27.9, 27.7 (2C), 27.3, 23.1 (2C), 22.7, 14.2 (2C), 14.1, 11.8 (2C).

Example 7

[0093] The present Example provides a compound I-7 represented by Formula I, which has a structural Formula as follows:

##STR00027##

[0094] Compound I-7 was prepared by the synthesis route as follows:

##STR00028##

[0095] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-7 (23.7 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; anhydride compound represented by Formula III-7 (28.2 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0096] (2) the solution 1 was added into the solution 2, and the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for 2 hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-7.

[0097] NMR characterization of compound I-7: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.48 (2H), 5.43 (2H), 5.21 (1H), 4.91 (1H), 3.31 (4H), 3.02 (1H), 2.70 (2H), 2.33 (2H), 2.0 (4H), 1.94 (2H), 1.84 (2H), 1.44 (4H), 1.33 (2H), 1.30 (2H), 1.30 (2H), 1.29 (2H), 1.26 (8H), 0.94 (6H), 0.88 (3H), 0.79 (6H).

[0098] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 135.6 (2C), 129.3 (2C), 128.9, 128.3, 55.5 (2C), 39.9 (2C), 37.4, 33.0, 31.9, 29.9, 29.7, 29.7, 29.6, 29.6, 29.3, 27.7, 27.3, 26.8 (2C), 26.7 (2C), 22.7, 14.3 (2C), 14.1, 11.7 (2C).

Example 8

[0099] The present Example provides a compound I-8 represented by Formula I, which has a structural Formula as follows:

##STR00029##

[0100] Compound I-8 was prepared by the synthesis route as follows:

##STR00030##

[0101] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-8 (24.2 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; decenyl glutaric anhydride compound represented by Formula III-8 (25.4 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0102] (2) the solution 1 was added into the solution 2, and the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for 2 hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-8.

[0103] NMR characterization of compound I-8: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.25 (4H), 3.02 (1H), 2.33 (2H), 1.94 (2H), 1.92 (2H), 1.84 (2H), 1.55 (4H), 1.33 (2H), 1.31 (4H), 1.30 (2H), 1.29 (2H), 1.26 (6H), 1.25 (4H), 1.19 (4H), 0.99 (4H), 0.88 (6H), 0.88 (3H).

[0104] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 128.9, 128.3, 52.4 (2C), 37.5 (2C), 37.4, 33.0, 32.0 (2C), 31.9, 29.9, 29.8 (2C), 29.7, 29.7, 29.3 (2C), 29.3, 27.7, 27.3, 23.0 (2C), 22.7, 14.1 (2C), 14.1, 11.6 (2C).

Example 9

[0105] The present Example provides a compound I-9 represented by Formula I, which has a structural Formula as follows:

##STR00031##

[0106] Compound I-9 was prepared by the synthesis route as follows:

##STR00032##

[0107] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-9 (24.2 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; decenyl pimelic anhydride compound represented by Formula III-9 (28.2 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0108] (2) the solution 1 was added into the solution 2, and the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for 2 hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-9.

[0109] NMR characterization of compound I-9: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.43 (1H), 5.21 (1H), 4.91 (1H), 3.25 (4H), 3.02 (1H), 2.21 (2H), 1.94 (2H), 1.92 (2H), 1.55 (2H), 1.55 (4H), 1.54 (2H), 1.33 (2H), 1.31 (4H), 1.30 (2H), 1.30 (2H), 1.29 (2H), 1.26 (8H), 1.25 (1H), 1.25 (4H), 1.19 (4H), 0.99 (6H), 0.88 (6H), 0.88 (3H).

[0110] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 130.9, 128.8, 52.4 (2C), 38.0, 37.5 (2C), 34.5, 34.0, 32.0 (2C), 31.9, 29.9, 29.8 (2C), 29.7, 29.7, 29.6, 29.6, 29.3, 29.3 (2C), 27.3, 25.9, 24.4, 23.0 (2C), 22.7, 14.1 (2C), 14.1, 11.6 (2C).

Example 10

[0111] The present Example provides a compound I-10 represented by Formula I, which has a structural Formula as follows:

##STR00033##

[0112] Compound I-10 was prepared by the synthesis route as follows:

##STR00034##

[0113] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-10 (29.4 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; decenyl pimelic anhydride compound represented by Formula III-10 (30.8 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0114] (2) the solution 1 was added into the solution 2, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-10.

[0115] NMR characterization of compound I-10: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.18 (1H), 5.21 (1H), 4.91 (1H), 3.18 (4H), 3.02 (1H), 2.87 (2H), 2.46 (4H), 2.21 (2H), 1.94 (2H), 1.55 (2H), 1.54 (2H), 1.52 (4H), 1.44 (4H), 1.38 (2H), 1.33 (2H), 1.30 (2H), 1.29 (4H), 1.29 (4H), 1.29 (4H), 1.27 (4H), 1.26 (2H), 1.26 (2H), 1.26 (2H), 1.26 (4H), 1.25 (2H), 1.25 (2H), 1.29 (2H), 0.93 (3H).

[0116] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 128.9, 130.9, 83.7 (2C), 68.6 (2C), 50.0 (2C), 38.0, 34.8, 34.0, 32.1, 29.9, 29.6, 29.6, 29.6, 29.3, 29.3, 29.3 (2C), 29.3 (2C), 29.0, 28.7 (2C), 28.7 (2C), 28.4 (2C), 27.0, 27.0 (2C), 24.7, 22.8, 18.4 (2C), 14.2.

Example 11

[0117] The present Example provides a compound I-11 represented by Formula I, which has a structural Formula as follows:

##STR00035##

[0118] Compound I-11 was prepared by the synthesis route as follows:

##STR00036##

[0119] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-11 (51.3 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; decenyl pimelic anhydride compound represented by Formula III-11 (42.0 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0120] (2) the solution 1 was added into the solution 2, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-11.

[0121] NMR characterization of compound I-11: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.18 (4H), 3.02 (1H), 2.87 (2H), 2.46 (4H), 2.21 (2H), 1.94 (2H), 1.55 (2H), 1.54 (2H), 1.52 (4H), 1.44 (4H), 1.33 (2H), 1.33 (2H), 1.30 (2H), 1.30 (2H), 1.29 (2H), 1.29 (4H), 1.29 (4H), 1.26 (20H), 1.26 (40H), 1.25 (2H), 1.25 (2H), 0.88 (3H).

[0122] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 130.9, 128.8, 83.7 (2C), 68.6 (2C), 50.0 (2C), 38.0, 34.8, 34.0, 31.9, 29.9, 29.9, 29.7, 29.7, 29.6 (8C), 29.6 (16C), 29.3, 29.3 (4C), 29.0, 29.0, 28.7 (6C), 27.3, 27.0 (2C), 24.7, 22.7, 18.4 (2C), 14.1.

Example 12

[0123] The present Example provides a compound I-12 represented by Formula I, which has a structural Formula as follows:

##STR00037##

[0124] Compound I-12 was prepared by the synthesis route as follows:

##STR00038##

[0125] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-12 (84.9 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; decenyl pimelic anhydride compound represented by Formula III-12 (18.0 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0126] (2) the solution 1 was added into the solution 2, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-12.

[0127] NMR characterization of compound I-12: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.88 (1H), 3.80 (1H).

[0128] 3.18 (4H), 2.77 (2H), 1.96 (2H), 1.52 (4H), 1.44 (2H), 1.30 (2H), 1.29 (104H), 1.28 (4H), 0.89 (3H), 0.88 (6H).

[0129] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 177.3, 173.6, 84.5, 78.6, 49.0 (2C), 35.2, 31.2, 29.0 (2C), 27.0, 22.4 (2C), 22.1 (52C), 21.5, 18.4, 14.1 (2C), 13.2.

Example 13

[0130] The present Example provides a compound I-13 represented by Formula I, which has a structural Formula as follows:

##STR00039##

[0131] Compound I-13 was prepared by the synthesis route as follows:

##STR00040##

[0132] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-13 (42.9 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; decenyl pimelic anhydride compound represented by Formula III-13 (61.8 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0133] (2) the solution 1 was added into the solution 2, and the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for 2 hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-13.

[0134] NMR characterization of compound I-13: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 3.25 (4H), 2.27 (1H), 2.21 (2H), 1.92 (2H), 1.55 (4H), 1.54 (2H), 1.49 (4H), 1.33 (2H), 1.26 (96H), 1.25 (12H), 1.19 (4H), 0.99 (6H), 0.88 (9H).

[0135] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 173.8, 52.3 (2C), 42.4, 37.5 (2C), 34.0, 33.1, 33.0, 32.3 (2C), 31.9, 31.9 (2C), 29.9 (2C), 29.8 (2C), 29.7, 29.6 (36C), 29.4, 29.3 (2C), 29.2 (2C), 29.0, 27.1 (2C), 26.4 (2C), 24.7, 22.8, 22.7 (2C), 14.1 (2C), 14.0, 11.6 (2C).

Example 14

[0136] The present Example provides a compound I-14 represented by Formula I, which has a structural Formula as follows:

##STR00041##

[0137] Compound I-14 was prepared by the synthesis route as follows:

##STR00042##

[0138] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-14 (27.0 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; decenyl pimelic anhydride compound represented by Formula III-14 (41.0 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0139] (2) the solution 1 was added into the solution 2, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-14.

[0140] NMR characterization of compound I-13: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 3.25 (4H), 2.33 (2H), 2.27 (1H), 1.92 (2H), 1.55 (4H), 1.54 (2H), 1.49 (4H), 1.26 (22H), 1.25 (10H), 1.19 (4H), 0.99 (6H), 0.88 (9H).

[0141] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 173.8, 52.3 (2C), 42.1, 37.5 (2C), 33.6, 33.1, 32.3 (2C), 31.9, 31.8, 29.9, 29.8 (2C), 29.6 (13C), 29.5 (2C), 29.3, 29.2, 27.1, 26.4, 24.4, 22.8, 22.7 (2C), 14.2, 14.1 (2C), 11.6 (2C).

Example 15

[0142] The present Example provides a compound I-15 represented by Formula I, which has a structural Formula as follows:

##STR00043##

[0143] Compound I-15 was prepared by the synthesis route as follows:

##STR00044##

[0144] (1) N,N-dihydrocarbonyl secondary amine represented by Formula II-15 (28.3 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; decenyl pimelic anhydride compound represented by Formula III-15 (28.1 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0145] (2) the solution 1 was added into the solution 2, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-15.

[0146] NMR characterization of compound I-15: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.74 (4H), 3.25 (4H), 3.02 (1H), 2.21 (2H), 1.94 (2H), 1.92 (2H), 1.55 (10H), 1.54 (2H), 1.33 (2H), 1.30 (2H), 1.29 (2H), 1.26 (6H), 1.25 (2H), 1.19 (4H), 0.99 (4H), 0.88 (3H).

[0147] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 130.9, 128.8, 52.4 (2C), 45.0 (2C), 38.0, 36.7 (2C), 34.5, 34.0, 31.9, 30.5 (2C), 29.9, 29.8 (2C), 29.7, 29.6, 29.4 (2C), 29.3, 27.3, 25.9, 24.4, 22.7, 14.1, 11.6 (2C).

Comparative Example 1

[0148] Comparative Example 1 provides a compound I-d1 represented by Formula I-d1, which has a structural Formula as follows:

##STR00045##

[0149] Compound I-d1 was prepared by the synthesis route as follows:

##STR00046##

[0150] (1) N,N-dihydrocarbonyl secondary amine represented by Formula I-d1 (15.7 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; anhydride compound represented by Formula III-d1 (28.2 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0151] (2) the solution 1 was added into the solution 2, and the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for 2 hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-d1.

[0152] NMR characterization of compound I-d1: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.02 (1H), 3.00 (4H), 2.33 (2H), 2.12 (2H), 1.94 (2H), 1.84 (2H), 1.55 (4H), 1.33 (2H), 1.31 (2H), 1.30 (2H), 1.29 (2H), 1.26 (8H), 0.99 (6H), 0.93 (6H), 0.88 (3H).

[0153] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 128.9, 128.3, 54.6 (2C), 37.4, 33.0 (2C), 32.9, 31.9, 29.9, 29.7, 29.7, 29.6, 29.6, 29.3, 28.2 (2C), 27.7, 27.3, 22.7, 18.1 (2C), 14.1, 11.3 (2C).

COMPARATIVE EXAMPLE 2

[0154] Comparative Example 2 provides a compound I-d2 represented by Formula I-d2, which has a structural Formula as follows:

##STR00047##

[0155] Compound I-d2 was prepared by the synthesis route as follows:

##STR00048##

[0156] (1) N,N-dihydrocarbonyl secondary amine represented by Formula I-d2 (11.5 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; anhydride compound represented by Formula III-d2 (11.4 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0157] (2) the solution 1 was added into the solution 2, and the thus obtained mixture was stirred while heating to 80° C. and then kept at 80° C. for 2 hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-d2.

[0158] NMR characterization of compound I-d2: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.38 (1H), 3.18 (2H), 2.94 (3H), 2.86 (1H), 2.56 (2H), 1.52 (2H), 1.62 (1H), 1.19 (2H), 1.17 (3H), 0.91 (6H).

[0159] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 177.3, 175.5, 52.4, 40.9, 37.0, 36.7, 36.3, 27.8, 24.7, 23.2 (2C), 17.2.

Comparative Example 3

[0160] Comparative Example 3 provides a compound I-d3 represented by Formula I-d3, which has a structural Formula as follows:

##STR00049##

[0161] Compound I-d3 was prepared by the synthesis route as follows:

##STR00050##

[0162] (1) N,N-dibutyl secondary amine represented by Formula I-d3 (12.9 g, 0.10 mol) was dissolved in toluene (20 mL) to obtain solution 1; anhydride compound represented by Formula III-d3 (28.1 g, 0.10 mol) was dissolved in toluene (30 mL) to obtain solution 2;

[0163] (2) the solution 1 was added into the solution 2, and the mixed solution was stirred while heating to 80° C. and then kept at 80° C. for two hours. After the reaction was finished, toluene was removed by concentrating in vacuum to obtain compound I-d3.

[0164] NMR characterization of compound I-d3: .sup.1H NMR (500 MHz, CDCl.sub.3), δ 10.58 (1H), 5.21 (1H), 4.91 (1H), 3.02 (1H), 3.18 (4H), 2.33 (2H), 1.94 (2H), 1.84 (2H), 1.52 (4H), 1.33 (2H), 1.31 (4H), 1.30 (4H), 1.29 (2H), 1.26 (8H), 0.99 (6H), 0.88 (3H).

[0165] .sup.13C NMR (500 MHz, CDCl.sub.3), δ 178.4, 170.8, 128.9, 128.3, 49.7 (2C), 37.4, 33.0, 30.0 (2C), 31.9, 29.9, 29.7, 29.7, 29.6, 29.6, 29.3, 27.7, 27.3, 20.1 (2C), 22.7, 14.1, 13.8 (2C).

Test Example 1

[0166] Test for enrichment of rare earth elements.

[0167] (1) the compounds prepared in the above Examples 1 to 15 and Comparative Examples 1 to 3 were used in weight of (6.6, 5.9, 6.6, 6.6, 6.1, 6.6, 6.6, 6.24, 6.97, 7.8, 11.66, 12.8, 13.01, 8.55, 7.3 and 5.53, 3.0, 5.3) g, respectively.

[0168] (2) The above extractants were respectively mixed with 0.96 mL of 10.8 mol/L sodium hydroxide aqueous solution, and saponified at 25° C. for 5 minutes to obtain viscous liquid of saponified extractants with saponification degree of 80%;

[0169] (3) at room temperature, the viscous liquid of saponified extractants were mixed with 2000 mL of ionic rare earth leaching solution for enrichment time of 0.5 hour. Ion-type rare earth leaching solution contained 15 rare earth elements including lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, with a total molar concentration of 0.00636 mol/L. pH=6.0. The concentration of rare earth ions in the water phase before and after enrichment was measured, and the total enrichment ratio of rare earth ions E % was calculated;

[0170] The specific test results (total enrichment ratio of rare earth ions) were shown in Table 1:

TABLE-US-00001 TABLE 1 Item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Total enrichment 97.5 98.4 98.5 97.5 98.9 98.6 ratio E % Item Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Total enrichment 98.7 98.9 98.9 96.8 95.6 99.5 ratio E % Comparative Comparative Comparative Item Example 13 Example 14 Example 15 Example 1 Example 2 Example 3 Total enrichment 98.5 96.7 97.7 94.5 92.7 93.6 ratio E %

[0171] It can be seen from the above table that the enrichment ratio of N,N-dihydrocarbonyl amide carboxylic acid prepared according to in Examples 1 to 15 is above 95%, while the total enrichment ratio of N,N-dihydrocarbonyl amide carboxylic acid in Comparative Examples 1 to 3 is below 95%. Therefore, the N,N-dihydrocarbonyl amide carboxylic acid according to the present invention can be used as extractant to enrich rare earth elements from raw material containing low-concentration rare earth elements with better enrichment effect.

Test Example 2

[0172] Test for Separating Yttrium Ion

[0173] (1) the compounds prepared in the above Examples 1 to 15 and Comparative Example 1 were respectively prepared into extractant solutions; to be specific, the extractants prepared in Examples 1 to 15 and Comparative Example 1 were taken in weight of 6.6 g, 5.9 g, 6.6 g, 6.6 g, 6.1 g, 6.6 g, 6.6 g, 6.24 g, 6.97 g, 7.8 g, 11.66 g, 12.8 g, 13.01 g, 8.55 g, 7.3 g and 5.53 g, 3.0 g, 5.3 g, respectively; toluene was taken in weight of 18.4 g, 19.1 g, 18.4 g, 18.4 g, 18.9 g, 18.4 g, 18.4 g, 18.76 g, 18.03 g, 17.2 g, 13.34 g, 12.2 g, 12.99 g, 16.45 g, 17.7 g and 19.47 g, 22.0 g, 19.7 g, respectively; the above two components were mixed to obtain extractant solutions with concentration of 0.52 mol/L;

[0174] (2) thus obtained extractant solutions were respectively mixed with 0.96 mL of 10.8 mol/L sodium hydroxide aqueous solution, and saponified at 25° C. for 5 min to obtain saponified extractant solutions with saponification degree of 80%;

[0175] (3) at room temperature, 25 mL of the saponified extractant solutions and 25 mL of mixed rare earth solution were mixed and extracted for 0.5 h. The mixed rare earth solution contained 15 rare earth elements including lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, with a concentration of 0.020 mol/L for each element. The concentrations of rare earth ions in aqueous phase before and after extraction were measured, and the relative separation coefficient β.sub.Ln/Y of each rare earth ion (Ln) relative to yttrium ion (Y) was calculated;

[0176] The specific test results (relative separation coefficient β.sub.Ln/Y of rare earth ions (Ln) relative to yttrium ions (Y)) were shown in Table 2.

TABLE-US-00002 TABLE 2 β.sub.Ln/Y La/Y Ce/Y Pr/Y Nd/Y Sm/Y Eu/Y Gd/Y Tb/Y Dy/Y Ho/Y Er/Y Tm/Y Yb/Y Lu/Y Example 1 1.10 1.29 1.72 2.06 3.01 2.96 2.18 2.26 2.30 2.39 2.48 2.59 2.88 3.15 Example 2 1.12 1.27 1.72 2.06 3.01 2.96 2.18 2.27 2.29 2.37 2.47 2.57 2.85 3.10 Example 3 1.11 1.30 1.72 2.06 3.01 2.96 2.18 2.26 2.29 2.37 2.46 2.57 2.85 3.14 Example 4 1.09 1.29 1.72 2.06 3.01 2.96 2.18 2.26 2.3 2.39 2.48 2.59 2.88 3.14 Example 5 1.12 1.27 1.72 2.06 3.01 2.96 2.18 2.27 2.29 2.37 2.47 2.57 2.85 3.11 Example 6 1.13 1.30 1.73 2.07 3.02 2.98 2.20 2.28 2.30 2.39 2.49 2.62 2.9 3.17 Example 7 1.14 1.31 1.73 2.07 3.02 2.98 2.20 2.28 2.30 2.39 2.50 2.62 2.91 3.19 Example 8 1.10 1.29 1.72 2.06 3.01 2.96 2.18 2.26 2.30 2.39 2.48 2.59 2.88 3.15 Example 9 1.21 1.32 1.82 2.08 3.02 2.97 2.19 2.28 2.32 2.42 2.51 2.61 2.97 3.35 Example 10 1.10 1.23 1.77 2.09 3.06 2.99 2.28 2.29 2.33 2.42 2.50 2.56 2.83 3.11 Example 11 1.13 1.32 1.80 2.04 3.05 2.98 2.12 2.23 2.32 2.41 2.48 2.54 2.86 3.13 Example 12 1.08 1.33 1.73 2.07 3.04 3.00 2.13 2.23 2.35 2.42 2.49 2.51 2.89 3.18 Example 13 1.16 1.30 1.74 2.09 3.03 2.93 2.12 2.29 2.30 2.40 2.43 2.59 2.88 3.19 Example 14 1.14 1.39 1.77 2.08 3.09 2.99 2.23 2.26 2.33 2.42 2.51 2.66 2.91 3.27 Example 15 1.28 1.35 1.75 2.05 3.12 3.02 2.24 2.27 2.32 2.43 2.54 2.68 2.91 3.29 Comparative 0.98 1.22 1.60 1.84 2.95 2.93 2.15 2.22 2.21 2.26 2.32 2.49 2.83 3.07 Example 1 Comparative 0.88 1.05 1.48 1.79 2.91 2.92 2.10 2.15 2.06 2.04 2.17 2.50 2.77 3.06 Example 2 Comparative 1.03 1.21 1.55 1.78 2.92 2.93 2.14 2.21 2.17 2.19 2.25 2.47 2.82 3.08 Example 3

[0177] It can be seen from table 2 that the separation coefficient (β.sup.Ln/Y) of N,N-dihydrocarbonyl amide carboxylic acids of Examples 1 to 15 for each rare earth element is higher than that of Comparative Examples 1 to 3. The N,N-dihydrocarbonyl amide carboxylic acids defined by the present invention can better separate and purify yttrium element from mixed rare earth raw materials.

Test Example 3

[0178] Stability Test

[0179] The stability of compound I-1 prepared in the above Example 1 was tested by the following procedure: compound I-1 was prepared into an extractant solution by dissolving 50.9 g of compound I-1 in 100 mL of toluene to prepare an extractant solution with a concentration of 1.0 mol/1; 50 mL of extractant solution and 50 mL of hydrochloric acid solution with concentration of 6 mol/L were mixed and stirred for 15 days, and another 50 mL of extractant solution and 50 mL of sodium hydroxide solution with concentration of 6 mol/L were mixed and stirred for 15 days, and then the extractant loss rate in both was tested by NMR. The stability of compounds according to Examples 2 to 15 and Comparative Examples was tested in the same manner as that of compound I-1;

[0180] Specific test results (the extractant loss rate in hydrochloric acid medium and liquid alkali medium) were shown in Table 3 below:

TABLE-US-00003 TABLE 3 in hydrochloric acid in liquid alkali medium, extractant medium, extractant Item loss rate (%) loss rate (%) Example 1 0.04 0.06 Example 2 0.04 0.06 Example 3 0.04 0.06 Example 4 0.04 0.06 Example 5 0.04 0.06 Example 6 0.05 0.07 Example 7 0.04 0.06 Example 8 0.05 0.07 Example 9 0.04 0.06 Example 10 0.04 0.06 Example 11 0.04 0.06 Example 12 0.02 0.05 Example 13 0.04 0.07 Example 14 0.03 0.06 Example 15 0.04 0.07 Comparative 0.07 0.08 Example 1 Comparative 0.07 0.09 Example 2 Comparative 0.06 0.08 Example 3

[0181] It can be seen from the test data in table 3 that the loss rate of N,N-dihydrocarbonyl amide carboxylic acid in hydrochloric acid medium was below 0.05%; and the loss rate in caustic soda liquid medium was below 0.07%. Therefore, the N,N-dihydrocarbonyl amide carboxylic acids prepared by the present invention have excellent chemical stability and can withstand strong acid and strong alkali without decomposition.

[0182] The applicant declares that the N,N-dihydrocarbonyl amide carboxylic acid and its preparation method and use according to the present invention are illustrated by the above Examples, but the present invention is not limited to the above Examples, which does not mean that the present invention should be implemented only by relying on the above Examples. It should be understood to those skilled in the art that any improvement to the present invention, equivalent replacement of raw materials, addition of auxiliary components, selection of specific embodiments, etc., shall fall within the scope of protection and disclosure of the present invention.