Condensation of diphenylguanidine and hexamethylenediamine

Article abstract of DOI:10.1134/S107042721310025X

Reaction of condensation of diphenylguanidine with hexamethylenediamine was performed. It is shown that the resulting condensate is a selective ion exchanger. Pleiades Publishing, Ltd., 2013.

Full text of DOI:10.1134/S107042721310025X

ISSN 1070-4272, Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 10, pp. 1629−1631. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © A.V. Golounin, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 10, pp. 1677−1678.
BRIEF
COMMUNICATIONS
Condensation of Diphenylguanidine
and Hexamethylenediamine
A. V. Golounin
Institute of Chemistry and Chemical Technology, Siberian Branch,
Russian Academy of Sciences, Krasnoyarsk, Russia
e-mail: Golounin@icct.ru
Received June 17, 2013
Abstract—Reaction of condensation of diphenylguanidine with hexamethylenediamine was performed. It is
shown that the resulting condensate is a selective ion exchanger.
DOI: 10.1134/S107042721310025X
It is known that long-chain alkylguanidines and
resins containing guanidine functions are anion
exchangers and have high capacity and relative
selectivity for gold [1, 2]. The alkylation of guanidine
and introduction of a guanidine function into the
polymer chain pose a difficult technological problem.
It has been shown previously how the water-soluble
polymer polyhexamethyleneguanidine can be converted
to a water-insoluble form [3].
because it has been found that gold can be quantitatively
eluted from low-basic ion exchangers with guanidine
functions [2].
EXPERIMENTAL
Interaction of 1N,3N-diphenylguanidine with
hexamethylenediamine. To 4.2 g (0.02 mol) of
1N,3N-diphenylguanidine and 2.5 g (0.021 mol) of
hexamethylenediamine were added 10 mL of glycerol
and two drops of phosphoric acid. The mixture was
heated to 160°C, with ammonia bubbles starting to be
evolved, as judged from the staining of litmus paper. The
temperature was gradually raised to 170°C, the mixture
was kept for 1 h and, when the gas evolution ceased, it
was cooled and poured over with an alkali solution. The
precipitated resin was washed with water and dried at
The readily available and inexpensive domestically
manufactured low-basic 1N,3N-diphenylguanidine
(pKa 10.12) is to be used to obtain water-insoluble ion
exchangers with guanidine functions [4, 5].
Because of the noticeable solubility in water,
diphenylguanidine itself cannot be used as an ion
exchanger. One of ways to render diphenylguanidine
insoluble is to make larger its molecular mass by, e.g.,
performingitscondensationwithhexamethylenediamine.
1
50°C. According to the H NMR spectrum, a complex
mixure of roducts was thus obtained.
As in the case of polyhexamethyleneguanidine
synthesis [6–9], performing the reaction of 1N,3N-
diphenylguanidine with hexamethylenediamine by
fusion of reagents at temperatures of 180°C and more
is impossible because 1N,3N-diphenylguanidine
decomposes at temperatures higher than 170°C [10].
It is known that fusion of guanidine with
hexamethylenediamine at temperatures of up to 180°C
yields an oligomer of polyhexamethyleneguanidine
[6, 7]. Because no reaction of this kind with 1N,3N-
diphenylguanidine has been carried out, it seems
advisable to perform the condensation reaction
with hexamethylenediamine. The condensation of
diphenylguanidine is also an issue of current interest
The condensation reaction in a dimethyl sulfoxide
solution yielded a pure product. For this purpose, 4.2 g
(0.02 mol) of 1N,3N-diphenylguanidine and 1.2 g
1629

1630
GOLOUNIN
Scheme. Formation scheme of 1.6-[di-21N(11N,31N-diphenylguanidine)]hexane.
NH
C H NH
C
HNC6H5
NH2 CH2
NH2
2
+
6
5
6
160oC
C6H5NH
C6H5NH
HNC6H5
HNC6H5
C
N
CH2
2 NH 3
CH2 CH2 CH2 CH2 CH2
+
N
C
(0.01 mol) of hexamethylenediamine were dissolved
under heating in 10 mL of dimethyl sulfoxide. Ammonia
bubbles started to evolve already at 140°C; with the
temperature raised to 160°C, the ammonia evolution
intensity increased and the reaction was complete in 1 h.
The reaction mass was poured into an aqueous solution
of an alkali. The resulting sticky resin was dissolved
in dichloroethane, the organic phase was washed
with water and dried with CaCl2, and the solvent was
evaporated to give 5.0 g of a transparent yellowish resin.
Its IR spectrum (in KBr) was recorded with a Specord
75-IR instrument, and the NMR spectrum, with a Bruker
Avance III 600 NMR spectrometer (1H: 600.13 MHz) in
deuteroacetone.
3450 cm–1 means that N–H bonds are present in the
condensation product.
The 1H NMR spectrum of the condensate in
(CD3)2CO contains broadened signals of methylene
protons at 1.37 ppm, two central aliphatic CH2 groups
94H) (see scheme), and two neighboring CH2 groups
(4H) at 1.60 ppm. The signal at 3.32–3.43 ppm should
be attributed to methylene groups bonded to nitrogen
atoms (4H).Amultiplet associated with protons of amino
groups is recorded at 6.6–6.7 ppm (4H), and the signal
of aromatic protons is recorded as a multiplet at 6.9–
7.4 ppm (20H). The signals are assigned in accordance
with the tables [11].
Thus, it can be stated that, under the conditions
described, 1N,3N-diphenylguanidine reacts with
hexamethylenediamine to give 1.6-[di-21N(11N,31N-
diphenylguanidine)]hexane insoluble in water and an
aqueous solution of an alkali.
Synthesis of an ion exchanger. To impart a developed
surface, 1.6 g of the condensate was dissolved in 5 mL
of dichloroethane. The solution was poured onto 5.6 g
of BAU-A carbon substrate and it was dried at 50°C.
Samples (0.05 g each) of the resulting ion exchanger
were poured over with 50 mL of a solution of complex
gold cyanide (97.5 mg L–1) and iron cyanide (337.5
mg L–1), and the mixture was agitated with a magnetic
rabble for 0.5 h. The content of gold in the aqueous
phase was monitored by the atomic-adsorption method
with an AAS-30 instrument.
Because the compounds with a guanidine function
are widely used as anion exchangers, the product
synthesized in the study was tested as such. The tests
demonstrated that, at pH 8, 8.4, 9.2, 9.6, and 9.9, gold
can be recovered with the condensate brought in a 0.5-
h contact with an alkaline cyanide solution containing
97.5 mg L–1 of gold and 337.5 mg L–1 of iron in amounts
of 92.5, 72.5, 40.0, 17.5, and 5.0 mg L–1, respectively. It
should be noted that the whole amount of iron remains
in solution in this case. Gold is desorbed by the known
method [2] with an aqueous solution of an alkali in the
presence of sodium benzoate.
The occurrence of a reaction between 1N,3N-
diphenylguanidine and hexamethylenediamine can be
judged from the evolution of ammonia from a heated
mixture of reagents. Apparently, the condensation
mechanism is similar to that in which Mannich bases
are formed.
This conclusion is supported by an analysis of the
IR spectrum (dichloroethane). The spectrum contains
strong bands at 2857, 2931, and 3058 cm–1, characteristic
of stretching vibrations of aromatic and aliphatic C–H
bonds. The presence of a broad strong band at 3200–
CONCLUSIONS
The condensation of 1N,3N-diphenylguanidine with
hexamethyleneguanidine was performed for the first
time. The condensate rather effectively sorbs gold and
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 86 No. 10 2013

CONDENSATION OF DIPHENYLGUANIDINE
1631
and Bases, London: Methuen, New York: Wiley, 1962.
6. RF Patent 2144024.
7. RF Patent 2241698.
shows a noticeable selectivity for iron ions.
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pp. 18–19.
1. US Patent 4814007.
9. RF Patent 2258696.
2. RF Patent 2114924.
3. RF Patent 2464226.
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