Claims:

WE CLAIM:

1. A compound of formula-I

wherein ‘Y’ is , , , , , , , or ; and
Z is lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs) or francium (Fr)

2. The compound as claimed in claim 1, wherein the compound of formula-I is
3. The compound as claimed in claim 1, wherein the compound of formula-I is
4. The compound as claimed in claim 1, wherein the compound of formula-I is
5. The compound as claimed in claim 1, wherein the compound of formula-I is
6. The compound as claimed in claim 1, wherein the compound of formula-I is

7. A process of preparing the compound of formula-I as claimed in claim 1, comprising steps of-
reacting amino acid or amino acid derivative with halogenating agent and alcohol to obtain corresponding ester of amino acid or corresponding ester of amino acid derivative;
reacting the ester of amino acid or the ester of amino acid derivative with reactant-I to obtain N-substituted ester of amino acid or N-substituted ester of amino acid derivative;
hydrolysing the N-substituted ester of amino acid derivative to obtain compound of formula-I; or
hydrolysing the N-substituted ester of amino acid to obtain corresponding N-acylated amino acid;
coupling the N-acylated amino acid with N-Hydroxysuccinimide (NHS) in presence of coupling agent and solvent to obtain NHS ester of N-acylated amino acid.
reacting the NHS ester of N-acylated amino acid with amino acid derivative to obtain N-acylated imino diacetic acid; and
hydrolysing the N-acylated imino diacetic acid to obtain the compound of formula-I
8. The process as claimed in claim 7, wherein the process of preparing the compound of formula-I comprises steps of-
reacting amino acid derivative with halogenating agent and alcohol to obtain corresponding ester of amino acid derivative;
reacting the ester of amino acid derivative with reactant-I to obtain N-substituted ester of amino acid derivative; and
hydrolysing the N-substituted ester of amino acid derivative to obtain compound of formula-I.
9. The process as claimed in claim 7, wherein the process of preparing the compound of formula-I comprises steps of-
reacting amino acid with halogenating agent and alcohol to obtain corresponding ester of amino acid;
reacting the ester of amino acid with reactant-I to obtain N-substituted ester of amino acid;
hydrolysing the N-substituted ester of amino acid to obtain corresponding N-acylated amino acid;
coupling the N-acylated amino acid with N-Hydroxysuccinimide (NHS) in presence of coupling agent and solvent to obtain NHS ester of N-acylated amino acid.
reacting the NHS ester of N-acylated amino acid with amino acid derivative to obtain N-acylated imino diacetic acid; and
hydrolysing the N-acylated imino diacetic acid to obtain the compound of formula-I
10. The process as claimed in claim 7 or 8, wherein the ester of amino acid derivative is reacted with reactant-I in presence of solvent selected from a group comprising dichloromethane, acetonitrile, tetrahydrofuran and N, N dimethylformamide; and base selected from a group comprising triethylamine, sodium hydroxide diisopropyl ethylamine, potassium hydroxide and pyridine.
11. The process as claimed in claim 7 or 8, wherein the hydrolysing the N-substituted ester of amino acid derivative is carried out in presence of a base selected from a group comprising triethylamine, sodium hydroxide, diisopropyl ethylamine, potassium hydroxide and pyridine sodium methoxide, sodium ethoxide and sodium isopropoxide;, solvent selected from a group comprising tetrahydrofuran (THF), dichloromethane, tertiary butyl methyl ether and diisopropyl ether; and alcohol selected from a group comprising methanol, ethanol and isopropanol.
12. The process as claimed in claim 7 or 9, wherein the ester of amino acid is reacted with reactant-I in presence of solvent selected from a group comprising dichloromethane, acetonitrile, tetrahydrofuran and N, N dimethylformamide; and base selected from a group comprising triethylamine, sodium hydroxide, diisopropyl ethylamine, potassium hydroxide and pyridine.
13. The process as claimed in claim 7 or 9, wherein the hydrolysing N-substituted ester of amino acid is carried out in presence of a base selected from a group comprising triethylamine, sodium hydroxide, pyridine and diisopropylethylamine; solvent selected from a group comprising tetrahydrofuran (THF), dichloromethane, tertiary butyl methyl ether and diisopropyl ether; and alcohol selected from a group comprising methanol, ethanol and isopropanol.
14. The process as claimed in claim 7 or 9, wherein the NHS ester of N-acylated amino acid is reacted with the amino acid derivative is carried out in presence of a base selected from a group comprising triethylamine, sodium hydroxide, pyridine and diisopropylethylamine; and a solvent selected from a group comprising mixture of water and tetrahydrofuran (THF), mixture of water and ethanol, mixture of water and methanol and mixture of water and IPA.
15. The process as claimed in claim 7 or 9, wherein the hydrolysing N-acylated imino diacetic acid is carried out in presence of a metal alkoxide selected from a group comprising sodium methoxide, sodium ethoxide and sodium isopropoxide; and alcohol selected from a group comprising methanol, ethanol and isopropanol.
16. The process as claimed in claim 7, wherein the amino acid is selected from a group comprising alanine, ß-alanine and glycine; the amino acid derivative is imino diacetic acid; the halogenating agent is selected from a group comprising thionyl chloride and oxalyl chloride; and the coupling agent is selected from a group comprising N,N'-Dicyclohexylcarbodiimide (DCC) and 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC).
17. The process as claimed in claims 7-9, wherein the reactant-I is represented by formula R1-X
wherein, R1 , , , or ;and
X is bromide, chloride, iodide or fluoride.
18. Use of the compound of formula-I as claimed in claim 1 for flotation of gangue selected from a group comprising alumina and silica. , Description:TECHNICAL FIELD
The present disclosure describes a compound consisting of ether, amine, acid and amide groups, which is represented by compound of formula-I. The disclosure also describes a process of preparing the said compound of formula-I. This disclosure further describes use of the compound of formula-I as flotation reagent for effective removal of gangue, such as alumina and silica.

BACKGROUND OF THE DISCLOSURE
In iron ore floatation, both direct and reverse floatation techniques have been employed. Chemical reagents are the most important part of the floatation techniques. Based on the function, the chemical reagents are divided into collectors, frothers, regulators and depressant. The selectivity of the collector and mineral interaction is determined by the characteristic of the functional group and the nature of the hydrocarbon chain. The capacity of a mineral to adsorb selectively adsorb said chemical reagent during floatation depends on chemical, thermodynamic and steric factors.

Beneficiation of iron ore slimes containing significant amount of Fe along with SiO2 and Al2O3 is concentrated either by reverse flotation of aluminosilicates (Kaolin) or direct anionic floatation of Fe. The cationic reverse floatation of aluminosilicates during beneficiation is the available mode for the concentration of low grade ores. However, the said cationic reverse floatation is not practiced widely because of the limitation of the reagents to float alumina. This is because the collectors available for reverse flotation are mostly silica selective and applicable for ores which have silica or quartz as the main impurity. And, alumina selective reagents are not available in the art. Thus, the present disclosure describes design and synthesis of collector chemical reagents for reverse floatation.

SUMMARY OF THE DISCLOSURE
The Present disclosure describes a compound of formula-I

wherein, ‘Y’ is an alkyl group or acyl group having carbon atoms ranging from C6 to C12; and ‘Z’ is alkali metal selected from a group comprising lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).

The present disclosure further describes a process of preparing the compound of formula-I.

The present disclosure furthermore describes about use of the compound of formula-I for flotation of gangue selected from a group comprising alumina and silica.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
In order that the disclosure may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures. The figures together with detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present disclosure where:

FIGURE 1 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-(dodecanoylazanediyl) diacetate.

FIGURE 2 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-((3-dodecanamidopropanoyl) azanediyl) diacetate.

FIGURE 3 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-((dodecanoylalanyl)azanediyl) diacetate.

FIGURE 4 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-((dodecanoylglycyl)azanediyl) diacetate.

FIGURE 5 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-(dodecylazanediyl)diacetate.

DETAILED DESCRIPTION
The present disclosure describes novel flotation reagent for removal of minerals including but is not limited to alumina and silica from ore, such as low-grade ore slime.

The present disclosure describes a compound of formula-I

wherein, ‘Y’ is an alkyl group or acyl group having carbon atoms ranging from C6 to C12; and ‘Z’ is alkali metal selected from a group comprising lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).

In an embodiment, in the compound of formula-I

wherein, ‘Y’ is , , , , , , , or .
In an embodiment, the compound of formula-I is
, termed as Sodium 2,2'-(dodecanoylazanediyl) diacetate.
In another embodiment, the compound of formula-I is
, termed as Sodium 2,2'-(3-dodecanamidopropanoyl azanediyl) diacetate.
In another embodiment, the compound of formula-I is
, termed as Sodium 2,2'-((dodecanoylalanyl)azanediyl) diacetate.
In another embodiment, the compound of formula-I is
, termed as Sodium 2,2'-((dodecanoylglycyl)azanediyl) diacetate.

In another embodiment, the compound of formula-I is
, termed as Sodium 2,2'-(dodecylazanediyl)diacetate.

In an embodiment, the compound of formula-I is a flotation reagent for removal of gangue including but is not limited to alumina and silica from ore, such as low-grade ore slime.

In another embodiment, the compound of formula-I is a flotation reagent for removal of gangue including but is not limited to alumina and silica from iron ore.

In an embodiment, the compound of formula-I has high selectivity and specificity for gangue including but is not limited to alumina and silica.

In an embodiment, the compound of formula-I possesses hydrophobic hydrophilic balance for effective flotation of gangue, such as alumina and silica.

In an embodiment, the compound of formula-I possesses high hydrogen bonding capabilities for effective interaction with gangue, such as alumina and silica.

The present disclosure describes a process for preparing the compound of formula-I

In an embodiment, the process of preparing the compound of formula-I comprises steps of-
reacting amino acid or amino acid derivative with halogenating agent and alcohol to obtain corresponding ester of amino acid or corresponding ester of amino acid derivative;
reacting the ester of amino acid or the ester of amino acid derivative with reactant-I to obtain N-substituted ester of amino acid or N-substituted ester of amino acid derivative;
hydrolysing the N-substituted ester of amino acid derivative to obtain compound of formula-I; or
hydrolysing the N-substituted ester of amino acid to obtain corresponding N-acylated amino acid;
coupling the N-acylated amino acid with N-Hydroxysuccinimide (NHS) in presence of coupling agent and solvent to obtain NHS ester of N-acylated amino acid.
reacting the NHS ester of N-acylated amino acid with amino acid derivative to obtain N-acylated imino diacetic acid; and
hydrolysing the N-acylated imino diacetic acid to obtain the compound of formula-I

In another embodiment, the process of preparing the compound of formula-I comprises steps of-
reacting amino acid derivative with halogenating agent and alcohol to obtain corresponding ester of amino acid derivative;
reacting the ester of amino acid derivative with reactant-I to obtain N-substituted ester of amino acid derivative; and
hydrolysing the N-substituted ester of amino acid derivative to obtain compound of formula-I.

In another embodiment, the process of preparing the compound of formula-I comprises steps of:
reacting amino acid with halogenating agent and alcohol to obtain corresponding ester of amino acid;
reacting the ester of amino acid with reactant-I to obtain N-substituted ester of amino acid;
hydrolysing the N-substituted ester of amino acid to obtain corresponding N-acylated amino acid;
coupling the N-acylated amino acid with N-Hydroxysuccinimide (NHS) in presence of coupling agent and solvent to obtain NHS ester of N-acylated amino acid.
reacting the NHS ester of N-acylated amino acid with amino acid derivative to obtain N-acylated imino diacetic acid; and
hydrolysing the N-acylated imino diacetic acid to obtain the compound of formula-I

In another embodiment, the process of preparing the compound of formula-I comprises steps of-
reacting amino acid or amino acid derivative with halogenating agent and alcohol at a temperature of about 0oC to 80oC for about 16 hours to obtain corresponding ester of amino acid or corresponding ester of amino acid derivative;
reacting the ester of amino acid or the ester of amino acid derivative with reactant-I at a temperature of about 25oC for about 16 hours to obtain N-substituted ester of amino acid or N-substituted ester of amino acid derivative;
hydrolysing the N-substituted ester of amino acid derivative at a temperature of about 0oC to 5oC for about 16 hours to obtain compound of formula-I; or
hydrolysing the N-substituted ester of amino acid to obtain corresponding N-acylated amino acid;
coupling the N-acylated amino acid with N-Hydroxysuccinimide (NHS) in presence of coupling agent and solvent at a temperature of about 25oC for about 16 hours to obtain NHS ester of N-acylated amino acid.
reacting the NHS ester of N-acylated amino acid with amino acid derivative at a temperature of about 100oC for about 20 hours to obtain N-acylated imino diacetic acid; and
hydrolysing the N-acylated imino diacetic acid at a temperature of about 25oC for about 16 hours to obtain the compound of formula-I

In an embodiment, the ester of amino acid is reacted with reactant-I in presence of solvent selected from a group comprising dichloromethane, acetonitrile, tetrahydrofuran and N, N dimethylformamide and base selected from a group comprising triethylamine, sodium hydroxide.

In an embodiment, the ester of amino acid derivative is reacted with reactant-I in presence of solvent selected from a group comprising dichloromethane, acetonitrile, tetrahydrofuran and N, N dimethylformamide and base selected from a group comprising triethylamine, sodium hydroxide, diisopropyl ethylamine, potassium hydroxide and pyridine.

In an embodiment, hydrolysing of the N-substituted ester of amino acid derivative is carried out in presence of a base selected from a group comprising triethylamine, sodium hydroxide, sodium methoxide, sodium ethoxide and sodium isopropoxide; solvent selected from a group comprising tetrahydrofuran (THF), dichloromethane, tertiary butyl methyl ether and diisopropyl ether; and alcohol selected from a group comprising methanol, ethanol and isopropanol.

In an embodiment, hydrolysing of the N-substituted ester of amino acid derivative is carried out in presence of a base selected from a group comprising sodium hydroxide, sodium methoxide, sodium ethoxide and sodium isopropoxide; solvent selected from a group comprising tetrahydrofuran (THF), dichloromethane, tertiary butyl methyl ether and diisopropyl ether; and alcohol selected from a group comprising methanol, ethanol and isopropanol.

In an embodiment, reacting the NHS ester of N-acylated amino acid with the amino acid derivative is carried out in presence of a base selected from a group comprising triethylamine, sodium hydroxide, pyridine and diisopropylethylamine; and a solvent selected from a group comprising mixture of water and tetrahydrofuran (THF), mixture of water and ethanol, mixture of water and methanol and mixture of water and IPA.

In an embodiment, the hydrolysing of the N-acylated imino diacetic acid is carried out in presence of a metal alkoxide selected from a group comprising sodium methoxide, sodium ethoxide and sodium isopropoxide and alcohol selected from a group comprising methanol, ethanol and isopropyl alcohol.

In an embodiment, in the process, the amino acid is selected from a group comprising alanine, ß-alanine and glycine.

In an embodiment, in the process, the amino acid derivative is imino diacetic acid.

In an embodiment, in the process, the halogenating agent is selected from a group comprising thionyl chloride and oxalyl chloride.

In an embodiment, in the process, the coupling agent is selected from a group comprising N,N'-Dicyclohexylcarbodiimide (DCC) and 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC).

In an embodiment, in the process, the reactant-I is represented by R1-X, wherein R1 is , , , or ; and X is bromide, chloride, iodide or fluoride.

In another embodiment, the process of preparing the compound of formula-I comprises steps of-
reacting iminodiacetic acid with thionyl chloride and ethanol to obtain corresponding ester of iminodiacetic acid;
reacting the ester of iminodiacetic acid with lauroyl chloride in presence of dichloromethane and triethylamine, to obtain N-acylated ester of iminodiacetic acid.
hydrolysing N-acylated ester of amino acid derivative in presence of 1:1 mixture of methanol and tetrahydrofuran and sodium hydroxide to obtain compound of formula-I.

In another embodiment, the process of preparing the compound of formula-I comprises steps of-
reacting iminodiacetic acid with thionyl chloride and ethanol to obtain corresponding ester of iminodiacetic acid;
reacting the ester of iminodiacetic acid with 1-bromo dodecane in presence of acetonitrile and N, N-Diisopropylethylamine, to obtain N-alkylated ester of iminodiacetic acid.
hydrolysing N-alkylated ester of amino acid derivative in presence of 1:1 mixture of methanol and tetrahydrofuran and sodium hydroxide to obtain compound of formula-I.
In another embodiment, the process of preparing the compound of formula-I comprises steps of-
reacting amino acid, such as alanine, ß-alanine and glycine thionyl chloride and ethanol to obtain corresponding ester of amino acid;
reacting the ester of amino acid in presence with lauroyl chloride in presence of dichloromethane, to obtain N-acylated ester of amino acid;
hydrolysing the N-acylated ester of amino acid in presence of sodium hydroxide and 1:1 mixture of methanol and tetrahydrofuran, to obtain N-acylated amino acid;
coupling N-acylated amino acid with N-hydroxysuccinimide (NHS) in presence of a N, N'-dicyclohexylcarodiimide and tetrahydrofuran, to obtain NHS ester of N-acylated amino acid;
NHS ester of N-acylated amino acid with iminodiacetic acid in the presence of triethylamine and ethanol to obtain N-acylated iminodiacetic acid; and
hydrolysing the N-acylated iminodiacetic acid in presence of sodium methoxide and methanol to obtain compound of formula-I.

In an embodiment, yield of the compound of formula-I obtained by the process of the present disclosure is ranging from about 70% to 90%.

In another embodiment, yield of the compound of formula-I obtained by the process of the present disclosure is about 70%, about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about 77%, about 78%, about 79%, about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89% or about 90%.

The present disclosure further describes use of the compound of formula-I for flotation of gangue.

In an embodiment, the compound of formula-I is used for flotation of gangue including but is not limiting to alumina and silica.

In an embodiment, the compound of formula-I causes selective removal of gangue, such as alumina and silica.

In another embodiment, the compound of formula-I causes selective removal of gangue, such as alumina.

Additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in art based upon the description provided. The embodiments provide various features and advantageous details thereof in the description. Descriptions of well-known/conventional methods and techniques are omitted so as to not unnecessarily obscure the embodiments. The examples provided herein are intended merely to facilitate an understanding of ways in which the embodiments provided may be practiced and to further enable those of skill in the art to practice the embodiments provided. Accordingly, the following examples should not be construed as limiting the scope of the embodiments.

EXAMPLES

Example 1: Process of preparing the compound of formula-I, termed as Sodium 2,2'-(dodecanoylazanediyl) diacetate
1. Preparation of Diethyl 2,2'-azanediyldiacetate (intermediate 1A)-
About 43.6ml of thionyl chloride was added drop wise to about 250ml of ethanol at a temperature of about 0 °C under stirring condition and the round bottom flask was fitted with reflux condenser along with calcium chloride guard tube. During the time of thionyl chloride addition, the reaction mixture was heated up i.e. reaction was exothermic. After about 30 minutes of stirring the reaction mixture was cooled to room temperature, followed by adding about 20g, 150.3mmol of iminodiacetic acid to the reaction mixture. Subsequently, about 100 ml ethanol was added again to the reaction and the reaction mixture was refluxed for about 12hours. Then the mixture was cooled to room temperature. The excess solvent was removed by high vacuum pump and the organic layer was diluted with ethyl acetate. The organic layer was extracted with saturated sodium bi carbonate solution and dried over anhydrous sodium sulphate. After evaporation of the organic layer, liquid residue obtained was intermediate 1A. The yield of the intermediate 1A was about 81% (i.e. 23 g). Rf value of the intermediate was 0.4 in about 3:2 of hexane-ethyl acetate.

2. Preparation of Dodecanoyl chloride (intermediate 1B):
About 43 ml of Oxalyl chloride was slowly added in about 200ml of dry di-chloromethane (DCC) in round bottom flask and to this reaction mixture about 50 ml of Dry DMF was added under ice-water condition. After about 30 minutes, about 20g, 99.8 mmol of Lauric acid was added to the reaction mixture at room temperature and stirring was continued for about 4 hours. Then the excess solvent was removed by high vacuum pump and residual oxalyl chloride was removed by co-evaporation with toluene to obtain intermediate IB.

3. Preparation of diethyl 2,2'-(dodecanoylazanediyl) diacetate (intermediate 1C):
About 21.8g, 99.8mmol of intermediate compound 1B was mixed with dry DCM and to this reaction mixture about 23g, 121.6mmol of intermediate 1A was added in the form of solution in dry DCM. The reaction mixture was stirred at room temperature. To this reaction mixture about 51ml, 365mmol of NEt3 was added. The stirring process was continued for about 12 hours at room temperature. The excess solvent was removed by high vacuum pump and diluted with DCM. The organic layer was extracted for about 3 times with about 2(N) HCl and then extracted for about 3 times by saturated NaHCO3. The organic layer was dried over anhydrous Na2SO4 to obtain intermediate 1C. The intermediate 1C was purified by silica gel having mesh size of about 60-120 by employing about 3:17 EtOAc-Hexane solvent system. The yield of the intermediate was about 78%. (i.e. 29 g).

4. Preparation of Sodium 2,2'-(dodecanoylazanediyl) diacetate (compound of formula-I):
About 27.24 g of intermediate 1C was dissolved in about 70 ml of 1:1 MeOH:THF and to the reaction mixture about 70 ml of 2M aqueous solution of sodium hydroxide was added at a temperature of about 0° to 5 °C. Then the reaction mixture was stirred at room temperature for about 12hours. The solvent was evaporated under reduced pressure and aqueous part was extracted with ethyl acetate. Remaining aqueous part was evaporated under vacuum followed, by triturating with about 1:4 ethyl acetate in hexane to obtain Sodium 2,2'-(dodecanoylazanediyl) diacetate (compound of formula-I). The yield of the compound of formula-I was 73%. (i.e. 18.5 g).

Figure 1 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-(dodecanoylazanediyl) diacetate, noted in the Example 1.

Example 2: Process of preparing the compound of formula-I, termed as Sodium 2,2'-(3-dodecanamidopropanoyl azanediyl) diacetate

1. Preparation of 3-Methoxy-3-oxopropan-1-aminium chloride (intermediate 2A)
About 18g, 202mmol of ß-alanine was suspended in about MeOH, followed by stirring to obtain a reaction mixture. To the reaction mixture which is maintained at ice cold condition, about 28.8 g thionyl chloride was added drop wise and stirring process was continued for about 12hours. The excess solvent was removed by high vacuum pump to obtain intermediate 2A. The yield of intermediate 2A was 88% (i.e. 24.8 g, 177.8 mmol).

2. Preparation of 3-Methoxy-3-oxopropan-1-aminium chloride (intermediate 2B)
About 20g, 143 mmol of intermediate 2A was dissolved in dry DCM to obtain a reaction mixture. To the reaction mixture about 25.8g, 118 mmol of Lauric acid chloride in about 100 ml of dry DCM was added, followed by stirring at room temperature. To this reaction mixture about 41.6 ml, 299.5 mmol of NEt3 was added. Then the stirring was continued for about 12hours at room temperature. The excess solvent was removed by high vacuum pump and diluted with DCM. The organic layer was extracted for about 3 times with about 2N HCl and then extracted for about 3 times with saturated NaHCO3. The organic layer was dried over anhydrous Na2SO4. The intermediate 2B was purified by silica gel having mesh size of about 60-120 using about 3:7 EtOAc-Hexane solvent system. The yield of the intermediate 2B was 74%. (i.e 25.2 g, 88.35 mmol).

3. Preparation of 3-Dodecanamidopropanoic acid (intermediate 2C)
About 25.2 g. 88.35 mmol of intermediate compound 2B was dissolved in about 125 ml of 1:1 mixture of THF and MeOH and to this reaction mixture about 125 ml, 2M NaOH was added. The reaction mixture was subjected to stirring at ice water condition for about 30 minutes and then the stirring was continued for about 12hours, followed by removing the solvent by vacuum pump. The organic layer was extracted with EtOAc and then acidified by about 2N HCl to obtain intermediate 2C as solid white precipitate. The intermediate 2C was characterized by LCMS and exactly matched with desired structure. The yield of the intermediate was 81% (i.e. 21.1 g, 77.75 mmol).

4. Preparation of 2,2'-((3-dodecanamidopropanoyl)azanediyl) diacetic acid (intermediate 2D)
About 21.1 g, 77.75 mmol of intermediate 2C and about NHS 10.74 g, 93.3 mmol were dissolved in about 800 ml dry THF to obtain a reaction mixture, to this reaction mixture about 19.2 g, 93.05 mmol of DCC was added, followed by stirring at room temperature for about 12hours and then the reaction mixture was filtered through sintered funnel. The filtrate was evaporated by vacuum pump to obtain NHS ester of N-dodecyl-ß-alanine. To about 50% aqueous ethanolic solution, about 28.63 g, 77.75 mmol of NHS ester of N-dodecyl-ß-alanine, about 30 ml, 294.8 mmol of NEt3 and 12.42 g, 93.3 mmol of imino di acetic acid was added, followed by stirring at a temperature of about 100o C for about 20 hrs. Then the reaction mixture was cooled to room temperature and EtOH solvent was evaporated through high vacuum pump and aqueous layer was washed with EtOAc. Then the aqueous layer was acidified with about 2N HCl to obtain intermediate 2D as white solid.

5. Preparation of 2 Sodium 2,2'-((3-dodecanamidopropanoyl) azanediyl) (compound of formula-I)
About 16.4 g, 42.48 mmol of intermediate 2D was dissolved in about 250ml of methanol to obtain a reaction mixture, to the reaction mixture about 4.1g, 76.46 mmol of sodium methoxide was added, followed by stirring at room temperature and continued the stirring for about 12hours. Then the excess solvent was evaporated by high vacuum pump, followed by triturating with about 1:4 ethyl actate in hexane to obtain Sodium 2,2'-((3-dodecanamidopropanoyl) azanediyl) (compound of formula-I). The yield of the compound of formula-I was 78%. (i.e. 14.3 g, 33.26 mmol).

Figure 2 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-((3-dodecanamidopropanoyl) azanediyl) diacetate, noted in the Example 2.

Example 3: Process of preparing the compound of formula-I, termed as Sodium 2,2'-((dodecanoylalanyl)azanediyl) diacetate

1. Preparation of 1-Methoxy-1-oxopropan-2-aminium chloride (intermediate 3A)
About 20g, 22.45 mmol of alanine was suspended in about 250 ml of MeOH, followed by stirring to obtain a reaction mixture. To this reaction mixture under ice cold condition, about 32 g thionyl chloride was added drop wise and stirring was continued for about 12hours. Then the excess solvent was removed by high vacuum pump to obtain intermediate 3A as a white solid. The yield of the intermediate 3A was 85% (i.e. 26.6 g).

2. Preparation of Methyl dodecanoylalaninate (intermediate 3B)
About 25.8g, 118 mmol of Lauric acid chloride was dissolved in dry DCM to obtain a reaction mixture, to this reaction mixture about 20g, 143 mmol of intermediate 3A was added in the form of solution of dry DCM, followed by stirring at room temperature. To this reaction mixture about 41.6 ml, 299.5mmol of NEt3 was added. Then the stirring process was continued for about 12hours at room temperature. The excess solvent was removed by high vacuum pump and diluted with DCM. The organic layer was extracted for about 3 times with 2N HCl and then extracted for about 3 times by saturated NaHCO3. The organic layer was dried over anhydrous Na2SO4 to obtain intermediate 3B. The intermediate 3B was purified by silica gel having mesh size of about 60-120 using about 3:7 EtOAc-Hexane solvent system. The yield of the intermediate 3B was 71%. (i.e. 24 g).

3. Preparation of Dodecanoylalanine (intermediate 3C)
About 24g, 84.2 mmol of intermediate 3B was dissolved in about 125 ml of 1:1 mixture of THF:MeOH to obtain a reaction mixture, to this reaction mixture about 125 ml, 2M NaOH was added, followed by stirring in ice water condition for about 30 minutes and then stirring was continued for about 12hours. Then the solvent was removed by vacuum pump. The organic layer was extracted with EtOAc and then acidified by about 2N HCl and to obtain intermediate 3C as solid white ppt. The intermediate 3C was characterized by LCMS and exactly matched with desired structure. The yield of the intermediate was 80% (i.e. 18.2 g).

4. Preparation of 2,2'-((Dodecanoylalanyl)azanediyl) diacetic acid (intermediate 3D)
About 18.2g, 67.3 mmol intermediate 3C and about 11.6g, 100.95 mmol of NHS was dissolved in about 700 ml dry THF, to obtain a reaction mixture. To the reaction mixture about 20.87g, 100.95 mmol of DCC was added, followed by stirring at room temperature for about 12hours and then the reaction mixture was filtered through sintered funnel. The filtrate was evaporated by vacuum pump to obtain residue of NHS ester of N-Dodecyl-Alanine. To about 100ml of 50% aqueous ehtanolic solution, about 24.9g, 67.3 mmol of NHS ester of N-Dodecyl-Alanine, about 26ml, 255.5mmol of NEt3 and about 10.8g, 80.76 mmol of imino di acetic acid was added, followed by stirring at a temperature of about 100o C for about 20hours and subsequently cooled to room temperature. EtOH solvent was evaporated through high vacuum pump and aqueous layer was washed with EtOAc. Then the aqueous layer was acidified with about 2N HCl and intermediate 3D was obtained as white solid.

5. Preparation of Sodium 2,2'-((dodecanoylalanyl)azanediyl) diacetate (compound of formula-I)
About 14.7g, 38.1mmol of intermediate 3D was dissolved in 200ml of methanol, to obtain a reaction mixture. To the reaction mixture about 3.6g, 66.2 mmol of sodium methoxide was added, followed by stirring at room temperature for about 12hours. Then the excess solvent was evaporated by high vacuum pump, followed by triturating with about 1:4 ethyl acetate in hexane, to obtain Sodium 2,2'-((dodecanoylalanyl)azanediyl) diacetate (compound of formula-I) as white solid. The yield of the compound of formula-I was 88.5%.

Figure 3 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-((dodecanoylalanyl)azanediyl) diacetate, noted in the Example 3.

Example 4: Process of preparing the compound of formula-I, termed as Sodium 2,2'-((dodecanoylglycyl)azanediyl) diacetate

1. Preparation of 2-Methoxy-2-oxoethan-1-aminium chloride (intermediate 4A)
About 12.0 g, 160mmol of Glycine was suspended in about 200ml of MeOH, followed by stirring to obtain a reaction mixture. To the reaction mixture maintained under ice cold condition, about 22.84 g thionyl chloride was added drop wise and stirring process was continued for about 12hours. Then the excess solvent was removed by high vacuum pump to obtain intermediate 4A as a white solid. The yield of the intermediate 4A was 90% (i.e. 18 g).

2. Preparation of Methyl dodecanoylglycinate (intermediate 4B)
About 21.8g, 99.8mmol of Lauric acid chloride was dissolved in dry DCM, to obtain a reaction mixture. To the reaction mixture, about 15g, 120mmol of intermediate 4B was added in the form of solution of dry DCM, followed by stirring at room temperature and about 41.6ml, 299.5 mmol of NEt3 was added. The stirring was continued for about 12 hours at room temperature. The excess solvent was removed by high vacuum pump and diluted with DCM. The organic layer was extracted for about 3 times with about 2N HCl and then extracted for about 3 times with saturated NaHCO3. The organic layer was dried over anhydrous Na2SO4. The intermediate 4B was purified by silica gel having mesh size of about 60-120 using about 3:7 EtOAc-Hexane solvent system. The yield of the intermediate 4B was 70%. (i.e 18.9 g).

3. Preparation of Dodecanoylglycine (intermediate 4C)
About 18.9g, 69.7 mmol of intermediate 4B was dissolved in about 100 mL of mixture of 1:1 THF:MeOH to obtain a reaction mixture. To the reaction mixture about 105 ml of 2M NaOH was added, followed by stirring at ice-water condition for about 30 minutes and then stirring was continued for about 12hours. Then the solvent was removed by vacuum pump. The organic layer was extracted with EtOAc and then acidified by about 2N HCl to obtain intermediate 4C as solid white ppt. The intermediate 4C was characterized by LCMS and exactly matched with desired structure. The yield of the intermediate 4C was 81% (i.e. 14.5 g).

4. Preparation of 2,2'-((dodecanoylglycyl)azanediyl) diacetic acid (intermediate 4D)
About 14.5 g, 56.4 mmol of intermediate 4C and about 7.8g, 67.7 mmol of NHS was dissolved in about 600 ml dry THF to obtain a reaction mixture. To the reaction mixture about 14g, 67.7 mmol of DCC was added, followed by stirring at room temperature for about 12hours and then the reaction mixture was filtered through sintered funnel. The filtrate was evaporated by vacuum pump and to obtain a residue of NHS ester of N-dodecyl-Glycine. To a 100 mL 50% aqueous ehtanolic solution, about 20g, NHS ester of N-dodecyl-Glycine, about 23 ml, 226 mmol of NEt3 and about 9g, 67.7 mmol of imino di acetic acid was added, followed by stirring at 100oC for about 20hours and cooling to room temperature. EtOH solvent was evaporated through high vacuum pump and aqueous layer was washed with EtOAc. Then the aqueous layer was acidified with 2(N) HCl to obtain intermediate 4D as white solid.

5. Preparation of Sodium 2,2'-((dodecanoylglycyl)azanediyl) diacetate (compound of formula-I)
About 14.7g, 38.1mmol of intermediate 4D was dissolved in 200ml of methanol, to obtain a reaction mixture. To the reaction mixture about 3.6g, 66.2 mmol of sodium methoxide was added, followed by stirring at room temperature for about 12hours. Then the excess solvent was evaporated by high vacuum pump, followed by triturating with about 1:4 ethyl acetate in hexane to obtain Sodium 2,2'-((dodecanoylglycyl)azanediyl) diacetate (compound of formula-I) as white solid. The yield of the compound of formula-I was 88.5%.

Figure 4 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-((dodecanoylglycyl)azanediyl) diacetate, noted in the Example 4.

Example 5: Process of preparing the compound of formula-I, termed as Sodium 2,2'-(dodecylazanediyl)diacetate

1. Preparation of diethyl 2,2'-azanediyldiacetate (intermediate 5A)
About 43.6ml of thionyl chloride was added drop wise to about 250ml of ethanol at a temperature of about 0 °C under stirring condition and the round bottom flask was fitted with reflux condenser along with calcium chloride guard tube. During the time of thionyl chloride addition, the reaction mixture was heated up i.e. reaction was exothermic. After about 30 minutes of stirring the reaction mixture was cooled at room temperature, followed by adding about 20g, 150.3mmol of iminodiacetic acid to the reaction mixture. Subsequently, about 100 ml ethanol was added again to the reaction and the reaction mixture was refluxed for about 12hours. Then the mixture was cooled to room temperature. The excess solvent was removed by high vacuum pump and the organic layer was diluted with ethyl acetate. The organic layer was extracted with saturated sodium bi carbonate solution and dried over anhydrous sodium sulphate. After evaporation of the organic layer, liquid residue obtained was intermediate 5A. The yield of the intermediate 5A was about 81% (i.e. 23 g). Rf value of the intermediate was 0.4 in about 3:2 of hexane-ethyl acetate.

2. Preparation of diethyl 2,2'-(dodecylazanediyl) diacetate (intermediate 5B)
About 25g, 132.2 mmol of intermediate 5A was dissolved in about 100 ml Toluene to obtain a reaction mixture. To the reaction mixture about 48ml, 278.53 mmol of DIEA and about 50ml, 206.43 mmol of 1-bromo dodecane was added. Then the reaction mixture was refluxed for about 12hours, followed by cooling. The excess solvent was removed by high vacuum pump and diluted with ethyl acetate. The organic layer was extracted for about 2 times with water and then the organic layer was dried over anhydrous Na2SO4 to obtain intermediate 5B. The intermediate 5B was purified by silica gel having mesh size of about 60-120 using 5% EtOAc-Hexane solvent system. The yield of the intermediate was 49%, i.e. 23.2 g (64.90 mmol).

3. Preparation of Sodium 2,2'-(dodecylazanediyl)diacetate (compound of formula-I)
About 27.24 g of intermediate 5B was dissolved in about 70 ml of 1:1 MeOH:THF and to the reaction mixture about 70 ml of 2M aqueous solution of sodium hydroxide was added at a temperature of about 0° to 5 °C. Then the reaction mixture was stirred at room temperature for about 12hours. The solvent was evaporated under reduced pressure and aqueous part was extracted with ethyl acetate. Remaining aqueous part was evaporated under vacuum, followed by triturating with about 1:4 ethyl acetate in hexane to obtain Sodium 2,2'-(dodecylazanediyl)diacetate (compound of formula-I). The yield of the compound of formula-I was 73%. (i.e. 18.5 g).

Figure 5 illustrates the scheme of preparation of the compound of formula-I termed as Sodium 2,2'-(dodecylazanediyl) diacetate, noted in the Example 5.

Example 6: Flotation test illustrating the removal of alumina and concentrating iron ore.
About 1000 ml of water was poured into the flotation cell and the about 500g of the iron ore sample was added to the floatation cell. The pH was maintained between 9.5 to 10.5 by adding NaOH. After about 5 minutes about 500-1000 ppm causticized starch solution was added, followed by adding the compound of formula-I to the samples and conditioning the sample for about 3 minutes to 5 minutes. Frother was added to the sample and after about 2minutes the air valve of the flotation cell was opened. The material was raked off after 30 seconds and froth was collected for about 5minutes. Tailings were collected separately. The products were dried, weighed and sent for chemical analysis.

Result and Inference
The feed alumina range was 2%-4% and silica range was 2.0%-4%. In all the flotation experiments, two fragments were collected basically that is froth and tailings. In a reverse flotation system, the froth is the impurity and the tailing which remains behind in the flotation machine is the product and is called the concentrate. The compound of formula-I afforded the final product, which contained alumina and silica in the range of 1.8%-2.8% and 1.2%-2.0% respectively with a yield of around 70%. The commercially available flotation reagents or collectors are silica specific and suitable for ores which contain silica/quartz as the major impure phase with iron ore. With the commercial collectors, silica was reduced to the desired level that is in the range of 2.0-2.5 but alumina levels in the concentrate was in the range of 3.0-3.5.

Fe(t)% Al2O3 (%) SiO2 (%) Yield (%)
Feed 58-61 2.5-4 2-4 100
Conc. Obtained by 2,2'-(dodecanoylazanediyl) diacetate (compound of formula-I) 62-64 2-3 1.2-2.2 75-80
Conc. Obtained by Sodium 2,2'-((3-dodecanamidopropanoyl) azanediyl) (compound of formula-I) 62-64 2.1-3 1.5-2.5 75-80
Conc. Obtained by Sodium 2,2'-((dodecanoylalanyl)azanediyl) diacetate (compound of formula-I) 62-64.5 1.8-2.4 1.5-2.5 60-70
Conc. Obtained by Commercial collector 62-63.5 3.0-3.5 1.2-2.2 50

In summary, the compound of formula-I showed good selectivity for minerals like silica and alumina in reverse floatation process giving high yields of iron ore concentrates as shown in the results above. The alumina levels in the final concentrate was brought down to a level of less than 2%Silica levels were also lowered to a great extent to less than 2%.