Synthesis and characterization of new extractants for Cu(II)

Article abstract of DOI:10.14233/ajchem.2013.13900

New extractants for Cu²⁺ ions in raw ore powders or waste water (fluid) were successfully synthesized recently in good yields. Their structures and purity were confirmed by 1H NMR and IR.

Full text of DOI:10.14233/ajchem.2013.13900

Asian Journal of Chemistry; Vol. 25, No. 8 (2013), 4229-4231
http://dx.doi.org/10.14233/ajchem.2013.13900
Synthesis and Characterization of New Extractants for Cu(II)
1,2,*
XING ZHANG1,2 and JIANBIN HUI
1Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P.R. China
2Tangshan High-tech Research and Transformation Center, Chinese Academy of Sciences, Tangshan 063020, P.R. China
*Corresponding author: E-mail: zkytszx@126.com
(Received: 13 April 2012;
Accepted: 6 February 2013)
AJC-12933
New extractants for Cu2+ ions in raw ore powders or waste water (fluid) were successfully synthesized recently in good yields. Their
structures and purity were confirmed by 1H NMR and IR.
Key Words: Extractant, Cu(II), Synthesized, Oximatio, Hydrazone formation.
suitable to low pH system, we have successfully synthesized
six new extractants recently in our laboratory and evaluate
their structures on the basis of their IR and 1H NMR.
INTRODUCTION
Copper, as one of the most important metals, is widely
used in many fields such as copper fitting, heat extracter tube
sheet, electric cable, lead wire, transformer, switch, printed
circuit board, vacuum pump, bullet, cannonball, pipe, pipe
fitting, copper also has a biological action at low. However,
more than 34 % of the copper mined is now in landfill, 18 %
of the copper mined was lost as tailings and other wastes during
milling and smelting1. Although pyrometallurgical treatment
of complex metal sources containing copper is frequently used
in practice, it is not suitable or economically viable when it is
used in the field of multi component metal alloys and other
complex materials with multi components.
EXPERIMENTAL
Preparation of 5-tert-butyl-2-hydroxybenzaldehyde
(A)10: Magnesium turnings (28.8 g, 1.2 mol) were added to
anhydrous methanol (535 mL) to form an 8 % w/w methanol
solution of magnesium methoxide. Toluene (160 mL) and the
solution of magnesium methoxide were stirred and refluxed
until all the magnesium was dissolved and H2 evolution ceased.
4-tert-butylphenol (300 g, 2 mol) was added and refluxed for
1 h. Toluene (330 mL) was added and the mixture was distilled
under vacuum to remove the methanol-toluene azeotrope.
Paraformaldehyde (117.6 g) in toluene (200 mL) was added
slowly with concurrent removal of solvent by distillation. After
cooling to room temperature, H2SO4 (10 %, 800 mL) was added
slowly with stirring and heated to 50 ºC to dissolve all solids.
The product was extracted with toluene (3 × 100 mL), washed
with water (3 × 200 mL), dried over MgSO4, concentrated in
vacuo and purified by column chromatography (eluting) to
yield a yellow oil (260.2 g, 73.1 %).
Solvent extraction technology offers a convenient method
for the extraction and separation of copper(II) from complex
mixtures as mentioned above and can be efficiently applied
for the selectively recovery of copper from leach liquors and
other waste solutions or fluids, so solvent extraction is becoming
increasingly important in the production of copper from nature
raw ores or other sources or solid waste recently, which are
suited to the processing of wastes such as slags2, tailings3, post-
flotation waste and mine waters4.
Preparation of (B): A solution of the hydroxylamine
hydrochloride (22.24 g, 0.32 mol) neutralized by NaHCO3 in
H2O(50 mL) was slowly added to A (53.4 g, 0.3 mol) in ethanol
(100 mL). The resulting mixture was stirred for 4 h under
reflux and the solvent was removed in vacuo to yield a white
solid which needs no further purification (50.2 g, 86.7 %).
Preparation of (C): A solution of A (53.4 g, 0.3 mol) in
ethanol (100 mL) was slowly added to methyl hydrazine (0.33
mol) in ethanol (50 mL). The resulting mixture was stirred for
4 h under reflux and the solvent was removed in vacuo to
Although some of the reagents of this category, namely
LIX265, LIX64N6, LIX622N7, LIX 84-I7, LIX9848 andAcorga
M56409, offer strong extraction of copper from acidic media,
many problems still remain unsolved. For example, they have
low exchange capacity for the ion exchange and the low
durability and unsatisfactory selectivity of the electrodialysis
membrane.
In order to develop new extraction agents with high
exchange capacity, strong durability, high selectivity and

4230 Zhang et al.
Asian J. Chem.
yield a yellow solid which needs no further purification (59.6 g,
96.4 %).
All the compound we have synthesized in our lab were
confirmed by 1H NMR and IR (Table-1).
Preparation of 3-bromo-5-tert-butyl-2-hydroxybenzal-
dehyde (D): Bromine (29.1 g, 0.185 mol) in glacial acetic acid
(500 mL) was added to a solution of (A) (31.2 g, 0.177 mol)
and NaOAc·3H2O (41 g, 0.35 mol) in glacial acetic acid (100
mL) via a dropping funnel over 4 h at 60 ºC. The yellow solution
was stirred for another 2 h. The solvent was removed in vacuo.
The solid was washed with Na2S2O5 solution (300 mL, 10 %
w/w), saturated NaHCO3 solution (400 mL) and petroleum ether
(100 mL) to give yellow crystals (35.9 g, 88.6 %).
OH
OH
N
NH2OH
(CH3O)2Mg
OH
OH
CH3CH2OH
paraformaldehyde
CHO
B
Toluene
H
N
OH
H
N
H2N
N
CH3CH2OH
A
HAc Br2
C
OH
Preparation of (E): A solution of the hydroxylamine
hydrochloride (10.48 g, 0.152 mol) neutralized by NaHCO3 in
H2O (60 mL) was slowly added to (D) (38.4 g, 0.15 mol) in ethanol
(100 mL). The resulting mixture was stirred for 4 h under reflux
and the solvent was removed in vacuo to yield a white solid which
needs no further purification (36.5 g, 86.6 %).
Br
OH
N
NH2OH
OH
CH3CH2OH
Br
CHO
H
N
E
OH
H2N
H
N
Br
N
CH3CH2OH
D
Preparation of (F): A solution of (E) (38.4 g, 0.15 mol)
in ethanol (100 mL) was slowly added to methylhydrazine
(0.16 mol) in ethanol (50 mL). The resulting mixture was
stirred for 4 h under reflux and the solvent was removed in
vacuo to yield a yellow solid which needs no further purifi-
cation (41.9 g, 98.3 %).
OH
CuBr
OH
DMF
N
CH3ONa
NH2OH
F
CH3CH2OH
OH
O
CHO
H
H
N
OH
H2
N
H
N
CH3CH2OH
N
Preparation of 5-tert-butyl-2-hydroxy-3-methoxybenz-
aldehyde (G): NaOCH3 (129.6 g, 2.4 mol) and CuBr (17 g)
was dissolved in the minimum anhydrous methanol (100 mL),
(D) (102.4 g, 0.4 mol) was dissolved in DMF (250 mL) and
poured into the refluxing mixture of the NaOCH3/MeOH solu-
tion. The resulting solution was refluxed 6 h. After the solution
was cooled to room temperature, 2500 mL H2O was added to
the solution, air pump filtration, the solid was washed with H2O
and petroleum ether to yield a yellow solid (44.9 g, 53.9 %).
Preparation of (H): A solution of the hydroxylamine
hydrochloride (0.33 g, 0.01 mol) neutralized by NaHCO3 in
ethanol (10 mL) was slowly added to G (2.08 g, 0.01 mol) in
ethanol (20 mL). The resulting mixture was stirred for 4 h under
reflux and the solvent was removed in vacuo to yield a yellow
solid which needs no further purification (1.89 g, 91.7 %).
Preparation of (I): A solution of G (2.08 g, 0.01 mol) in
ethanol (10 mL) was slowly added to methylhydrazine (0.01
mol) in ethanol (10 mL). The resulting mixture was stirred for 4
h under reflux and the solvent was removed in vacuo to yield a
yellow solid which needs no further purification (2.16 g, 97 %).
G
I
Schemes-I: Reaction pathway to (C), (D), (E) (F), (G) and (I)
TABLE-1
CHARACTERIZATION DATA OF THE INTERMEDIATES
A, B, D AND E AS WELL AS OF THE C-SUBSTITUTED
PENTAMETHINE CYANINE DYES C, F AND G
IR (νmax cm-1)
Compound
1H-NMR(CDCl3)
A
B
1.35 [s, 9H, C(CH )3], 6.92-7.33 (m,
3
3H, Ar-H) 9.87 (s, 1H, CHO), 10.80 (s,
1H, OH)
3359 (PhOH) 1.25 [s, 9H, C(CH )3], 4.01 (s, 2H, OH)
3
2966 (C-H) 6.92-7.33 (m, 3H, Ar-H), 8.38 (s, 1H,
CH=N) 10.71 (s, 1H, OH)
1623 (C=N)
3392 (PhOH) 1.34 [s, 9H, C(CH )3], 2.09 (s, 1H, -
C
3
NH-C) 3.00 (d, 3H, N-CH3), 6.91-7.24
2957 (C-H)
1623 (C=N )
(m, 3H, Ar-H) 8.39 (s, 1H, CH=N),
11.21 (s, 1H, OH)
D
E
3356 (PhOH) 1.35 [s, 9H, C(CH )3], 7.52-7.82 (m,
3
2H, 2Ar-H) 9.87 (s, 1H, CHO), 10.44
2960 (C-H)
(s, 1H, OH)
1689 (CHO)
3170 (PhOH) 1.25 [s, 9H, C(CH )3], 7.48 ( d, 1H,
3
RESULTS AND DISCUSSION
Ar-H), 7.51 (d, 1H, Ar-H), 8.15 (s, 1H,
CH=N), 10.70 (s, 1H, OH ), 11.70 (s,
1H, OH)
2970 (C-H)
1623 (C=N)
Six new extrantants were synthesized from p-tert-butyl-
phenol, as shown in Schemes-I: (1) Synthesis of 5-tert-butyl-
2-hydroxybenzaldehyde (A)10, the reaction involves magnesium
mediated ortho-formylation. (2) Synthesis of brominating
salicylaldehydes (D), bromine in glacial acetic acid was added
to the solution of (A) and sodium acetate in glacial acetic acid
via a dropping funnel. (3) Mthoxylation: the reaction in this
work was carried out by adding (D) in DMF into a refluxing
mixture of a fresh 4 M NaOMe/MeOH solution, CuBr under
nitrogen. (4) Oximation: (B)11, (E), (H) were synthesized by
adding hydroxylamine to aldehydes. (5) Hydrazone Formation:
(C), (F), (I) were synthesized by slowly adding the appropriate
salicylaldehyde precursors to hydrazines.
F
3347 (PhOH) 1.25 [s, 9H, C(CH )3], 2.09 (s, 1H, -
3
NH-C) 2.82 (s, 3H, N-CH ), 7.07-7.43
3
2950 (C-H)
1623 (C=N)
(d, 2H, Ar-H), 8.15 (s, 1H, CH=N),
11.44 (s, 1H, OH)
3355 (PhOH) 1.34 [s, 9H, C(CH )3], 3.82 (s, 3H,
G
H
3
OCH ) 7.15-7.22 (2H, 2Ar-H), 9.92 (s,
3
1H, CHO) 10.65 (s, 1H, OH)
2971 (C-H)
1689 (CHO)
3378 (PhOH) 1.25 [s, 9H, C(CH )3], 3.85 (s, 3H,
OCH ) 6.78 (d, 1H, Ar-H), 6.85 (d, 1H,
3
2967 (C-H)
1623 (C=N)
3
Ar-H), 8.16 (s, 1H, CH=N), 10.70 (s,
1H, OH), 11.70 (s, 1H, OH)
I
3362 (PhOH) 1.26 [s, 9H, C(CH )3], 2.09 (s, 1H, -
3
2971 (C-H)
1623 (C=N)
NH-C) 2.92 (s, 3H, N-CH ), 3.85 (s,
3
3H, OCH3) 6.76-6.89 (d, 2H, Ar-H),
8.15 (s, 1H, CH=N), 11.21 (s, 1H OH)

Vol. 25, No. 8 (2013)
Synthesis and Characterization of New Extractants for Cu(II) 4231
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Conclusion
Six extractants were synthesized in good yields. The
structure and purity of the prepared compounds were confirmed
by 1H NMR and IR.
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ACKNOWLEDGEMENTS
This work has been financially supported by Liu Jing-ling,
Zheng Wen-jing, Zhao Yuan-yuan.
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