Synthesis of phosphorous acid and its derivatives based on the reaction of elemental phosphorus (P4) and aqueous solution of choline in the presence of the hydroxides of earth alkali metals

Article abstract of DOI:10.1002/hc.20472

A nonchloric method for the synthesis of phosphorous acid and barium and calcium phosphites is proposed, involving the reaction of elemental phosphorus (P₄) with aqueous barium and calcium hydroxides in the presence of quaternary ammonium base (choline). Conditions for the preparation of high-purity phosphorous acid based on the oxidation of the hypophosphite ion to the phosphite ion in a strong alkali medium were studied.

Full text of DOI:10.1002/hc.20472

Heteroatom Chemistry
Volume 19, Number 5, 2008
Synthesis of Phosphorous Acid and Its
Derivatives Based on the Reaction of Elemental
Phosphorus (P ) and Aqueous Solution
4
of Choline in the Presence
of the Hydroxides of Earth Alkali Metals
Elena V. Platova, Elvira S. Batyeva, Lidiya I. Kursheva,
and Oleg G. Sinyashin
A. E. Arbuzov Institute of Organic and Physical Chemistry of Russian Academy of Sciences,
Kazan Scientific Center, Kazan, Arbuzov Str. 8, 420088, Russia
Received 20 June 2007
In connection with our research directed toward
ABSTRACT: A nonchloric method for the synthesis
the development of new methods for the synthesis of
of phosphorous acid and barium and calcium phos-
phosphorus organic compounds, we have reported
phites is proposed, involving the reaction of elemental
the synthesis of hypophosphite based on the reac-
phosphorus (P4) with aqueous barium and calcium
tion of elemental phosphorus with ethylene oxide in
hydroxides in the presence of quaternary ammonium
the presence of aqueous solution of tertiary amines
base (choline). Conditions for the preparation of high-
[2].
purity phosphorous acid based on the oxidation of the
hypophosphite ion to the phosphite ion in a strong
ꢀ
C
alkali medium were studied. 2008 Wiley Periodicals,
Inc. Heteroatom Chem 19:517–519, 2008; Published on-
line in Wiley InterScience (www.interscience.wiley.com).
DOI 10.1002/hc.20472
RESULTS AND DISCUSSION
We have established that the reaction of elemental
phosphorus with choline and water is accompanied
by the elimination of hydrogen (H2), instead of phos-
phine, as it is usually performed when other tertiary
amines were used [2]. Thus, the synthesis of choline-
hypophosphite is described as shown below
INTRODUCTION
In recent years, we studied the reaction of elemental
phosphorus (P4) with proton donor reagents using
bifunctional compounds, particularly metal com-
plexes or amines, which appeared to promote the
cleavage of the P4 tetrahedron [1].
Note that some quantity of cholinephosphite
along with cholinehypophosphite is always formed
in the above reaction. As it is known for the inor-
ganic reactions [3,4], in the competition between the
possible formation of hypophosphite and phosphite,
Correspondence to: L. I. Kursheva; e-mail: kursheva@iopc.knc.
ru.
Contract grant sponsor: Russian Foundation for Basic
Research.
Contract grant number: 06-03-32180.
2008 Wiley Periodicals, Inc.
c
ꢀ
517

518 Platova et al.
the strong alkali medium is more favored than the
formation of phosphite.
with the reagent molar ratio of 1:5:5:5.5:20. The
reaction was conducted at 50–100◦C up to the
total conversion of phosphorus. After that, the
formed BaHPO3 was filtered off and washed with
water (yield 28 g, 80%). The filtrate, contain-
ing β-hydroxyethyltrimethylammonium hydrox-
ide (choline), may be recovered in the reaction.
The precipitate of barium phosphite was added
to a stirred 11%–12% solution of sulfuric acid
(1.2–1.3 times excess of the stoichiometry) at
80–90◦C. The formed BaSO4 was filtered off and
washed with water. The obtained 6%–7% solu-
tion of phosphorous acid was purified of traces
of sulfate ions with Ba(OH)2. The yield of phos-
phorous acid was 10.2 g (77%). 31P NMR, δ = 3.2,
1 JP-H = 675 Hz.
In connection with this, we studied the condi-
tions for the preparation of phosphorous acid via
the oxidation of the hypophosphite ion to the phos-
phite ion in a strong alkaline medium, particularly,
45%–50% solution of choline in the presence of earth
alkali metal hydroxides Ba(OH)2 or Ca(OH)2, which
promote the shifting of the reaction equilibrium to-
ward the formation the respective metal phosphites.
For the more full transformation of the hypophos-
phite ion into the phosphite ion, barium or calcium
phosphites were removed from the reaction mixture
as precipitate and then were decomposed with the
excess of sulfuric acid. The following purification
of phosphorous acid from the traces of sulfate ions
with calculated quantity of the hydroxides of earth
alkali metals resulted in phosphorous acid. At that
time, the filtrate, which contains solution of choline,
may be regenerated. The total process consists of the
following principal stages:
(b) Interaction of P4, β-Hydroxyethyltrimethyl-
ammonium Hydroxide, and Water in the Presence
of Barium Hydroxide. In a similar manner to
that described for the preparation of phos-
phorous acid according to (a), from P4 (5 g),
It should be noted that this method allows the prepa-
ration of a high purity phosphorous acid referring to
the phosphorus (80%–90% yield).
Thus, the ecologically pure nonchloric method
is proposed for the preparation of phosphorous
acid based on the reaction of white phosphorus
with hydroxide β-hydroxyethyltrimethylammonium
(choline) in water in the presence of barium or cal-
cium hydroxides.
β-hydroxyethyltrimethylammonium hydroxide
(24.4 g), water (21.7 g), and Ba(OH)2(70 g),
being in the reagent molar ratio of 1:5:30:5.5,
phosphorous acid (yield 10.4 g, 79%) was
obtained.
(c) Interaction of P4, Trimethylamine, Ethylene Ox-
ide, and Water in the Presence of Calcium Hy-
droxide. To a mixture of P4 (5 g), trimethylamine
(11.9 g), ethylene oxide (8.9 g), and water (14.5 g)
at 40–45◦C (mp of P4), Ca(OH)2 (19.1 g) was
added, with a reagent molar ratio of 1:5:5:30:6.5.
The reaction was conducted in a strong alkali
medium at 50–100◦C until the total conversion
of phosphorus. After that, the formed CaHPO3
was filtered off and washed with water (yield
12.4 g, 64.1%). The precipitate of calcium phos-
phite was decomposed with 11%–12% solution
of sulfuric acid (1.2–1.3 excess of the stoichiom-
etry) at 80–90◦C. The formed CaSO4 was filtered
off and washed with water. The obtained 5%–6%
solution of phosphorous acid was purified from
the traces of sulfate ions with Ca(OH)2. The yield
EXPERIMENTAL
The 31P NMR spectra were recorded on a Bruker
MSL-400 (162 MHz, external 85% phosphoric acid).
Preparation of the Phosphorous Acid
(a) Interaction of P4, Trimethylamine, Ethylene Ox-
ide, and Water in the Presence of Barium Hydrox-
ide. To a mixture of P4 (5 g), trimethylamine
(11.9 g), ethylene oxide (8.9 g), and water (14.5 g)
at 40–45◦C (mp of P4), Ba(OH)2 (70 g) was added,
Heteroatom Chemistry DOI 10.1002/hc

Synthesis of Phosphorous Acid and Its Derivatives Based on the Reaction of Elemental Phosphorus (P4) and Choline 519
of phosphorous acid was 8.5 g (64.5 %). 31P NMR,
REFERENCES
δ = 3.2, 1 JP-H = 675 Hz.
[1] Batyeva, E. S.; Badeeva, E. K.; Kursheva, L. I.;
Platova, E. V.; Gubaidullin, A. T.; Litvinov, I. A.;
Sinyashin, O. G. Phosphorus, Sulfur Silicon 2005,
180, 1405–1409.
[2] Fridland, N. S.; Ivanov, B. Eug; Krokhina, S. S.;
Platova, E. V. Zh Org Khim 1994, 30(10), 1462–
1467.
[3] Brodsky, A. A.; Ershov, V. A.; Blankstein, B. A.,
Talanov, N. D. Processing of Phosphorus; Leningrad,
1985 (in Russian).
[4] Romanova, N. V.; Demidenko, I. V. Usp Khim 1975,
44, 2150–2170.
(d) Interaction of P4, β-Hydroxyethyltrimethyl-
ammonium Hydroxide, and Water in the Presence
of Calcium Hydroxide. In a similar manner to
that described for the preparation of phos-
phorous acid according to (c), from P4 (5 g),
β-hydroxyethyltrimethylammonium
hydrox-
ide (24.4 g), water (21.7 g), and Ca (OH)2
(19.1 g), with a reagent molar ratio of 1:5:30:6.5,
the phosphorous acid (yield 8.9 g, 68%) was
obtained.
Heteroatom Chemistry DOI 10.1002/hc