RU2202541C2 - 1,4-dialkylethylenediamine-4'-thioaldehydes as extractants of precious metals and method of their synthesis - Google Patents

Abstract

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to novel chemical compounds, namely 1,4- dialkylethylenediamine-4'-thioaldehydes, that show high extractive capacity with regards to some precious metals. Owing to this capacity these compounds can be used as extractants of precious metals. These compounds provide 45-50% extraction of silver from aqueous solutions and practically complete extraction from nitrate solutions. Invention relates also to method of synthesis of these compounds that involves treatment of 2-imidazolidinethione with n-butyl- or n-amyl bromide in the presence of potassium hydroxide in medium of dimethylsulfoxide (DMSO) at 50-80 C. The yield is 75-82%. EFFECT: improved method of synthesis, enhanced effectiveness of extraction. 2 cl, 10 ex

Description

которые могут быть использованы в качестве экстрагентов благородных металлов - золота, серебра и некоторых металлов платиновой группы.The invention relates to the field of organic chemistry, specifically to new chemical compounds - 1,4-dialkylethylenediamine-4 ¹ -thioaldehydes of the general formula

which can be used as extractants of noble metals - gold, silver and some metals of the platinum group.

1,4-Di-n-butyl-ethylenediamine-4 ¹ -thioaldehyde (I) and 1,4-di-n-butyl-ethylenediamine-4 ^1- thioaldehyde (II), their properties and the preparation method are not described in the literature.

Known structural analogues of 1,3-dialkyl derivatives of 2-imidazolidinedione and a method for their preparation by treating the corresponding N, N ¹ -dialkyl derivatives of ethylenediamine with carbon disulfide in an alcohol medium, followed by heating to remove hydrogen sulfide (John TV, Ectens, C.O. J. AnLChem Soc. 1942, v. 64, p. 2706; Lien JC, Hussain EM // Chem. Abetr. 1971, v. 74, 878931; S. Chan-Der Li, Sharon Mella L, Sartorelli AC // Chem Abetr. 1981, v. 95. 90793), as well as 1,3-di-n-amyl-2-imidazolidinedione. The latter was obtained by reacting 2-imidazolidinedione with a stoichiometric amount of n-amyl bromide in the presence of potassium hydroxide in dimethyl sulfoxide at 20-50 ^° C in 37% yield (USSR Author's Certificate, 1719400, class C 07 D 233/02).

 The property analogues are known that are used for the extraction group concentration of noble metals, such as N-octylaniline, diphenylthiourea (USSR Author's Certificate, 687073, class C 07 D 213/74), 2-octylaminopyridine (KinderJ., Shiayn. // Nucl . and Radiochem. 1986. V. 8. N. 2. P. 108-112). But these extractants are difficult to access, insufficiently effective, poorly selective.

 Known trioctylamine (TOA), which is used to concentrate precious metals (Xiaugyin Jian Ming Wang // Acta Sci natur unit pekines. 1986. N. 4. P. 21. isie). However, the known extractant does not have sufficient efficiency and selectivity, and also exhibits reducing properties with respect to gold (III).

 The problem to which the claimed technical solution is directed is to expand the assortment of extractants with high extraction ability in relation to some noble metals.

In the claimed technical solution, new compounds are synthesized - 1,4-di-n-butylethylenediamine-4 ^1- thioaldehyde (I) and 1,4-di-n-amylethylenediamine-4'-thioaldehyde (II). The method of obtaining is that 2-imidazolidinedione is reacted with n. -butyl bromide or n-amyl bromide in the presence of potassium hydroxide in DMSO at 50-80 ^° C and with a ratio of 2-imidazolidinedione: KOH: alkyl bromide = 1: 2.4: 3.6.

 The extraction is carried out at room temperature by mixing hydrochloric acid solutions containing gold and some platinum group metals or aqueous and nitric acid solutions containing silver with solutions of extractants in chloroform, the phase ratio is 1: 1.

 The essence of the technical solution is illustrated by the following examples.

Example 1. 1,4-Di-n-butylethylenediamine-4-thioaldehyde (I). To a mixture of 10.2 g (0.1 mol) of 2-imidazolidinedione, 13.5 g (0.24 mol) of potassium hydroxide in 50 ml of DMSO at 50 ^° C., 49.3 g (0.36 mol) of n-butyl bromide are added. . The reaction mixture was stirred at this temperature for 6 hours and left overnight. The next day, 100 ml of water are poured into the reaction mixture and extracted (3 • 100 ml) with chloroform, the extract is washed (2 • 10 ml) with water, dried with anhydrous magnesium sulfate, the solvent is distilled off, the residue is distilled in vacuo and 16.2 g are obtained after distillation (75%) of chromatographically pure 1,4-di-n-butylethylenediamine-4-thioaldehyde (I) with so on. 135-138 ^o C / 3 mm., N _d ²⁰ 1.4910. Found,%: C 60.90; H 11.00; N 12:63; S 14.50. C ¹¹ N ₂₄ N ₂ S. Calculated. %: C 61.06; H 11.18; N, 12.95; S 14.82. NMR ¹³ C (I), (δ ppm, CDCl ₃ ): 14.20 (C ^8.8 ); 20.50 (C ^7.7 ); 29.10 (C ^6.6 ); 48.20 (C ^5-1 ); 51.00 (C ² ); 52.30 (C ⁵ ); 56.60 (C ³ ); 187.00 (C ^4-1 ). NMR ¹ H (I) δ ppm, CBCI ₃ ): 0.95 (t, J 6.5 Hz, 6H, 2 C ₃ ) N; 1.0 (NH); 1.2-1.46 (m, 8H ^6,7,6,1,7 'CH ₂ CH ₂ ); 2.6 (d, J 6.9 Hz 2H ² , NCH ₂ ); 2.8 (d, J 7.25 Hz, 2H ^5-1 (CH ₂ ); 3.20 (d, J 7.25 Hz, 2H ³ NCH ₂ CH ₂ N; 3.5 (d, J 6, 9 Hz, 2H ³ CH ₂ CH ₂ N, 9.5 (s, 1H, HCS).

Example 2. 1,4-Di-n-amylethylenediamine-4'-thioaldehyde (II). To a mixture of 153 g (1.5 mol) of 2-imidazolidinedione, 202.5 g (3.6 mol) of potassium hydroxide in 1.2 L of DMSO, 571 ml (711.5 g or 4.7 mol) are added at 50 ^{° C.} n-amyl bromide for 3 hours. At this temperature, stir 6 hours. Then pour 1 liter of water and extract (3 • 300 ml) with chloroform, the extract is washed (2 • 100 ml) with water, dried with anhydrous magnesium sulfate, the solvent is distilled off, the residue is distilled, the residue is distilled. in vacuum and get 298 g (82%) of 1,4-di-n-amylethylenediamine-4 ¹ -thioaldehyde (II), so bales. 155-160 ^o mm,
n _d ²⁰ 1.4970; d ₄ ²⁰ 0.9598. Found,%: C 63.66; H 11.38; N, 11.59; S 12.96. C ₁₃ H ₂₈ N ₂ S. Calculated,%: C 63.88; H 11.55; N, 11.46; S 13.11. IR spectrum ν (cm '): 1572 (NC = S);
3068 (NH). ¹ H NMR (8 ppm, CDCI ₃ ): 0.90 (t, J 2.5 Hz, 6H, 2CH ₃ ); 1.27-1.3 (m, 8H ^7.9.7 - ^1.9-1 );
1.5 (q, J 7.5 Hz, 2H ⁶ ); 1.66 (q, J 7,3 Hz, 2 H ⁶ - ^1.); 2.6-2.8 (m, 4H ^2.51 , CH ₂ ); 3.09 (t, J 7 Hz, 2H ⁵ ); 3.2 (1, J 6.9 Hz, 2H ₃ CH ₂ ); 6.93 (s., L, HC = S); 7.06 (s, 1H, NH). ¹³ C NMR (δ ppm, CDCI ₃ ): 13.98 (C ^8.8-1 ); 22.66 (C ^7.7-1 ); 26.84 (C ^6.6-1 ); 29.08 (C ^9.9-1 ); 29.5 (C ⁵ ); 49.13 (C ⁵ - ¹ );
50.47 (C ² ); 57.2 (C ³ ); 182.66 (C, C = S).

Example 3. 1,4-Di-n-butylethylenediamine-4-thioaldehyde (I). To a mixture of 10.2 g (0.1 mol) of 2-imidazolidinedione, 13.5 g (0.24 mol) of potassium hydroxide in 50 ml of DMSO at 80 ^° C., 49.3 g (0.36 mol) of n-butyl bromide are added. . The reaction mixture was stirred at this temperature for 3 hours and left overnight. The next day, 100 ml of water is poured into the reaction mixture and extracted (2 • 50 ml) with chloroform, the extract is washed (2 • 10 ml) with water, dried with anhydrous magnesium sulfate, the solvent is distilled off, the residue is distilled in vacuo and 17.5 g are obtained after distillation (81%) of chromatographically pure 1,4-di-n-butylethylenediamine-4-thioaldehyde (I) with so on. 133-136 ^o C / 3 mm., N _d ²⁰ 1.4900. Found,%: C 60.90; H 11.00; N, 12.63; S 14.50. C ₁₁ H ₂₄ H ₂ S. Calculated,%: C 61.06; H 11.18; N, 12.95; S 14.82.

Example 4. To a mixture of 20.2 g (0.2 mol) of 2-imidazolidinedione, 32.8 g (0.48 mol) of 100% potassium hydroxide (or 0.58 mol of 82% KOH) in 50 ml of DMSO is added at 80 ^o With 100 ml (0.72 mol) of n-amyl bromide for 1.5 hours. The reaction mixture is stirred at this temperature for 4 hours, cooled, poured 100 ml of water, the organic layer is separated, the aqueous layer is extracted with chloroform (2 • 50 ml) , combined with the main layer, washed with 30 ml of water, the solvent is distilled off in vacuo, the residue is distilled from a Kleisen flask and 40 g (82%) of chromatographically pure 1,4-di-n-amylethylenediamine-4 ^1- thioaldehyde (II) are obtained, t bale 155-160 ^o C / 2 mm, n _d ²⁰ 1.4970; n _d ²⁰ 0.9598. Found,%: C 63.66; H 11.38; N, 11.59; S 12.96. C ₁₃ H ₂₈ N ₂ S. Calculated,%: C 63.88; H 11.55; N, 11.46; S 13.11. IR spectrum ν (cm ^-1 ):
1572 (NC = S); 3068 (NH).

 Example 5. Extraction of gold (III) and platinum group metals from analytical solutions with reagents I and II. To 5 ml of a 0.1 mol / L hydrochloric acid solution containing 0.01 mol / L of palladium (II), platinum (IV) and gold (III), add 5 ml of a 0.2 mol / L solution of reagent I or II in chloroform and produce extraction for 1 min. The phase separation is almost instant and clear. In one extraction step, these metals are extracted 100%.

 Example 6. The extraction of silver (I) from analytical solutions of reagents I and II. To 5 ml of 0.1 mol / L silver nitrate containing 0.02 mol / L silver (I) - solution (a) or 0.02 mol / L silver nitrate aqueous solution - solution (b) add 5 ml 0.05 mol / L solution of reagent I or II in chloroform and extraction is carried out for 20 minutes The results of the analysis of raffinates showed that in one step of extraction from solution (a) with reagents I or II, silver (I) is extracted by 50 and 45%, respectively, and from solution (b) it is almost completely (not less than 99.8%).

Example 7. Reagents I and II were tested to separate gold (III), palladium (II), platinum (IV) from rhodium (III) from analytical solutions. To 5 ml of 0.1 mol / L hydrochloric acid solution containing 0.01 mol / L of palladium (II), gold (II), platinum (IV) and rhodium (III), add 5 ml of 0.2 mol / L solutions reagent I or II in chloroform and extracted for 5 minutes The phases are separated. For one extraction step, the degree of extraction of gold (III), palladium (II), platinum (IV) is not less than 99.8%. The separation factor of these metals from rhodium (III) is 5 • 10 ⁴ .

 Example 8. Extraction concentration of gold (III), palladium (II), platinum (IV), indium (IV), ruthenium (III) from analytical solutions. To 5 ml of 0.1 mol / L hydrochloric acid solution containing 0.01 mol / L of gold (III), palladium (II), platinum (IV), iridium (IV) and 0.001 mol / L of ruthenium (III) are added 5 ml of a 0.2 mol / L solution of reagent I or II in chloroform and extracted for 30 minutes. In one extraction step, the extraction of all these metals into the organic phase is at least 99.9%. The formation of the third phase was not observed.

 Example 9. Extraction separation of gold (III), palladium (II), platinum (IV) and iridium (IV) from associated non-ferrous and ferrous metals. To 5 ml of 0.1 mol / L hydrochloric acid solution containing 0.01 mol / L of gold (III), palladium (II), platinum (IV), indium (IV), as well as 15 g / l of copper (II ), iron (III), cobalt (II) and nickel (II), 5 ml of a 0.2 mol solution of reagent I or II in chloroform are added and the phases are stirred for 30 minutes. After separation, the phases are separated. Analysis showed that after one extraction step, the extraction of gold (III) and platinoids into the organic phase is at least 99.9%. The content of the remaining components in the aqueous phase (copper, iron, nickel, cobalt) has not changed.

 Example 10. Extraction of silver (I) and palladium (II) from a solution simulating a spent electrolyte solution. To 5 ml of a 0.5 mol / L nitric acid solution containing 30.5 g / L silver and 19.5 g / L palladium, 5 ml of a 0.5 mol / L solution of reagent I in chloroform was added. As a result of one extraction step (contact time of the phases 20 min), silver (I) is extracted into the organic phase by 45.9%, palladium (II) by not less than 99.5%.

 Thus, for the first time, compounds I and II were obtained with yields of 75-82%, which were tested as extractants of noble metals.

The proposed extractants allow highly efficient and quick extraction of gold (III) and some platinum group metals from hydrochloric acid solutions. Moreover, the almost complete extraction of these metals and their deep separation from the accompanying base metals is possible in one extraction step. Extraction of silver passes from aqueous solutions by 45-50%, and from nitric acid solutions practically completely. The use of 1,4-dialkylethylenediamine-4 ¹ -thioaldehydes simplifies the extraction process due to the lack of preliminary operations that are characteristic of known reagents. The extractants used in the claimed method are practically insoluble in the aqueous phase, the phase separation is fast and clear.

Claims (2)

1. 1,4-Di-n-alkylethylenediamine-4'-thioaldehydes of the formula

R = C ₄ H ₉ (I)
R = C ₅ H ₁₁ (II)
as extractants of noble metals. 2. A method of producing 1,4-dialkylethylenediamine-4'-thioaldehydes, comprising reacting 2-imidazolidinedione with alkyl bromides in the presence of potassium hydroxide in dimethyl sulfoxide, characterized in that the ratio of 2-imidazolidinedione: potassium hydroxide: alkyl bromide reagents is 1: 2.4 : 3.6; temperature 50-80 ^o C.