Synthesis and biological activity of quaternary phosphonium salts based on 3-hydroxypyridine and 4-deoxypyridoxine

Article abstract of DOI:10.1007/s11172-016-1334-y

Methods for the synthesis of quaternary phosphonium salts based on 3-hydroxypyridine and 4-deoxypyridoxine were developed. Some of obtained compounds possess high antibacterial and antitumor activity in vitro.

Full text of DOI:10.1007/s11172-016-1334-y

Russian Chemical Bulletin, International Edition, Vol. 65, No. 2, pp. 537—545, February, 2016
537
Synthesis and biological activity of quaternary phosphonium salts
based on 3ꢀhydroxypyridine and 4ꢀdeoxypyridoxine*
N. V. Shtyrlin, R. M. Vafina, M. V. Pugachev, R. M. Khaziev,
E. V. Nikitina, M. I. Zeldi, A. G. Iksanova, and Yu. G. Shtyrlin
Kazan (Volga Region) Federal University, Education and Research Center of Pharmacy,
18 ul. Kremlevskaya, 420008 Kazan, Russian Federation.
Fax: +7 (843) 233 7531. Eꢀmail: Yurii.Shtyrlin@gmail.com
Methods for the synthesis of quaternary phosphonium salts based on 3ꢀhydroxypyridine and
4ꢀdeoxypyridoxine were developed. Some of obtained compounds possess high antibacterial
and antitumor activity in vitro.
Key words: 3ꢀhydroxypyridine, 4ꢀdeoxypyridoxine, phosphonium salts, antibacterial actiꢀ
vity, antitumor activity.
Nowadays, the area of application of quaternary phosꢀ
phonium salts is very wide. In particular, they are used as
catalysts in enantioselective synthesis,1—3 phaseꢀtransfer
catalysts,4—6 ionic liquids,7—10 as well as for the synthesis
of polymers based on alkenes obtained by Wittig reacꢀ
tion.11,12 It is also necessary to note a high biological acꢀ
tivity of quaternary phosphonium salts: anticholinestꢀ
erase,13,14 antitumor,15 antiviral,16 analgesic,17 antibacteꢀ
rial,18—20 and antiparasitic.21 Let us specially mention Viꢀ
zomitin, an agent developed in our country, which conꢀ
tains a quaternary phosphonium salt SkQ1 (Skulachev ion)
as an active component and is used as a keratoprotective
agent for treatment of syndrome of "dry eye" and other eye
diseases.22,23
Earlier,24,25 we have obtained a number of quaternary
phosphonium salts based on pyridoxine (vitamin B6) deꢀ
rivatives, some of these salts possess high antibacterial
activity against the strains Staphylococcus aureus and Staꢀ
phylococcus epidermidis (the minimum inhibiting concenꢀ
tration values (MIC) <5 μg mL–1). In continuation of the
systematic studies of pyridoxine derivatives,24—29 in the
present work we synthesize quaternary phosphonium salts
based on the closest pyridoxine structural analogues:
3ꢀhydroxyꢀ2ꢀ(hydroxymethyl)pyridine, 3ꢀhydroxyꢀ2,6ꢀ
bis(hydroxymethyl)pyridine, as well as vitamin B6 antagꢀ
onist 4ꢀdeoxypyridoxine. The synthesized compounds were
tested for antibacterial activity and antitumor activity
in vitro.
tion of the corresponding monoꢀ and bishydroxymethyl
derivatives 2 and 3. Subsequent chlorination of these comꢀ
pounds was carried out by reflux in thionyl chloride for
12 h. The last step of the reflux of chloro derivatives 4 and
5 in acetonitrile with an excess of tertiary phosphines
(triphenylphosphine, tributylphosphine, tris(pꢀtolyl)phosꢀ
phine, tris(2ꢀthienyl)phosphine, tris(4ꢀfluorophenyl)ꢀ
phosphine) led to the target phosphonium salts 6a—e and
7a—e (Scheme 1).
Pyridoxine hydrochloride (8) according to Scheme 2
was used to synthesize in fourꢀfive steps monophosphoniꢀ
um salts based on 4ꢀdeoxypyridoxine 13a—c and 14a—c
via an initial reduction of the hydroxymethyl group at
position 4 of the pyridine ring in pyridoxine with zinc in
acetic acid and the formation of acetate 9. Subsequent
removal of the acetate protection in acidic medium with
further chlorination of the hydroxymethyl group of
4ꢀdeoxypyridoxine 10 with thionyl chloride30 led to chloꢀ
ro derivative 11. Acylation of the aromatic hydroxy group
in this compound and, in the last step, the reaction of
chloro derivatives 11 and 12 with tertiary phosphines
(triphenylphosphine, tris(pꢀtolyl)phosphine, tributylphosꢀ
phine) in acetonitrile gave the corresponding quaternary
phosphonium salts 13 and 14.
Compound 13a was chosen to demonstrate that phosꢀ
phonium salts based on 4ꢀdeoxypyridoxine can be syntheꢀ
sized by much more simple method in two steps (Scheme 3).
In the first step, pyridoxine dichloro derivative 15
was obtained as hydrochloride according to the proceꢀ
dure described earlier.31 In the second step, compound
15 was reacted with a fourꢀfold molar excess of triphenꢀ
ylphosphine in DMF at 90 °C for 7 h. However, instead
of expected bisderivative 16, the monophosphonium salt
13a was isolated. In our opinion, this fact can be exꢀ
plained as follows: when the reaction mixture is workedꢀ
Quaternary phosphonium salts based on 3ꢀhydroxypyꢀ
ridine were synthesized in three steps, first, through
the hydroxymethylation of 3ꢀhydroxypyridine (1) with
paraformaldehyde in an alkaline medium with the formaꢀ
* Dedicated to Academician of the Russian Academy of Sciencꢀ
es N. S. Zefirov on the occasion of his 80th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 0537—0545, February, 2016.
1066ꢀ5285/16/6502ꢀ0537 © 2016 Springer Science+Business Media, Inc.

538
Russ.Chem.Bull., Int.Ed., Vol. 65, No. 2, February, 2016
Shtyrlin et al.
Scheme 1
6, 7: R = Ph (a), Bun (b), pꢀtolyl (c), 2ꢀthienyl (d), 4ꢀFC6H4 (e)
Reagents and conditions: i. (a) CH2O, NaOH, H2O, 90 °C; (b) HCl (gas), MeC(O)Me; ii. CH2O, NaOH, H2O, 90 °C;
iii. SOCl2, reflux; iv. PR3, MeCN, reflux.
Scheme 2
13, 14: R = Ph (a), pꢀtolyl (b), Bu (c)
Reagents and conditions: i. Zn, AcOH; ii. HCl, EtOH—H2O; iii. SOCl2, CHCl3, reflux; iv. MeC(O)Cl, NEt3, CH2Cl2;
v. PR3, MeCN, reflux; vi. PR3, MeCN, 55 °C.
up and the phosphonium salt is extracted into water, the
phosphonium fragment at position 4 of pyridoxine
undergoes selective hydrolysis with the formation of a
methyl group.
Screening of antibacterial activity of phosphonium salts
in vitro was carried out on the strains of conditionallyꢀ
pathogenic microorganisms: Staphylococcus aureus ATCC
29213, Staphylococcus epidermis, Bacillus subtilis, Escheriꢀ

Phosphonium salts of pyridoxine analogues
Russ.Chem.Bull., Int.Ed., Vol. 65, No. 2, February, 2016
539
Scheme 3
as well as earlier obtained phosphonium salts based on
pyridoxine,24,25 exhibit antibacterial activity predominantꢀ
ly against the strains of gramꢀpositive bacteria. Among the
phosphonium salts based on 3ꢀhydroxypyridine, the most
active was bisphosphonium salt 7c containing pꢀtolyl subꢀ
stituents at the phosphorus atom. The MIC values for this
compound on the strains of gramꢀpositive bacteria and
E. coli varied within 0.5—4 μg mL–1. Considerably less
active was bisphosphonium salt 7a containing phenyl subꢀ
stituents at the phosphorus atom. Other bisphosphonium
salts virtually do not possess antibacterial activity. Among
the monophosphonium salts, compounds 6c, 13b, and 14b
containing pꢀtolyl substituents at the phosphorus atom are
characterized by weak antibacterial activity.
For compounds 6c and 7c exhibiting the highest antiꢀ
bacterial activity, we studied mutagenicity on the auxꢀ
otrophic for histidine strains Salmonella typhimurium TA98
and Salmonella typhimurium TA100 (Table 2). It was found
that these compounds did not possess mutagenic effect.
The studies of antitumor activity of synthesized phosꢀ
phonium salts were carried out on the breast cancer cells
MCFꢀ7 (Table 3). Doxorubicin, one of the most widely
used cytostatic agents, was used as a reference drug. Comꢀ
pounds 6c, 7c, and 14b exhibited high antitumor activity
(the value IC50 ≈ 2.8—3.7 μmol L–1) comparable with
that in the case of doxorubicin. Somewhat lower activity
was demonstrated by compounds 7a, 6b, and 13b (the
value IC50 ≈ 25—32 μmol L–1). Other compounds were
considerably less active.
Reagents and conditions: i. SOCl2, CH2Cl2, reflux;
ii. PPh3, DMF, 90 °C; iii. H2O.
chia coli ATCC 25922, Pseudomonas aeruginosa ATCC
27853, Klebsiella pneumoniae. Table 1 summarizes the
minimum inhibiting concentration (MIC) values of the
phosphonium salts in comparison with the known antibiꢀ
otic of "last hope" vancomycin.
In conclusion, a number of new quaternary phosphoꢀ
nium salts based on 3ꢀhydroxypyridine and 4ꢀdeoxypyridꢀ
It is necessary to note a narrow range of the action of
all the compounds synthesized, which, like vancomycin,
Table 1. Antibacterial activity in vitro of monoꢀ and bisphosphonium salts
Comꢀ
pound
MIC/μg mL–1
Gramꢀpositive bacteria
Gramꢀnegative bacteria
S. aureus
S. epidermidis
B. subtilis
E. coli
K. pneumoniae P. aeroginosa
АТСС 29213
АТСС 25922
АТСС 27853
6а
6b
6c
6d
6e
7а
7b
7c
1000
>1000
100
>1000
1000
125
500
>1000
16
>1000
1000
125
1000
>1000
1000
>1000
62.5
>1000
1000
250
1000
>1000
>1000
>1000
>1000
>1000
>1000
250
1000
>1000
>1000
>1000
>1000
>1000
>1000
250
62.5
>1000
>500
250
>1000
4
>1000
4
>1000
0.5
>1000
4
7d
7e
500
500
500
250
500
500
62.5
>1000
2.5
250
125
250
62.5
500
>500
>500
250
250
250
500
500
500
500
500
500
62.5
>1000
1000
>1000
>1000
250
250
250
>1000
>1000
>1000
>1000
>1000
>1000
250
250
250
>1000
>1000
>1000
>1000
13а
13b
13c
14а
14b
14c
Vancoꢀ
mycin
250
1000
62.5
1000
2.5
62.5
>1000
2.5

540
Russ.Chem.Bull., Int.Ed., Vol. 65, No. 2, February, 2016
Shtyrlin et al.
Table 2. Mutagenicity of some compounds* at the concentraꢀ
tions of 1, 10, and 100 μg mL–1
sodium hydroxide (1.26 g, 31.5 mmol), and 37% aqueous soluꢀ
tion of formaldehyde (3.00 g, 37.0 mmol) in water (15 mL) was
heated for 3 h at 90 °C. Then, the reaction mixture was cooled to
~20 °C and neutralized by the addition of glacial acetic acid.
A solution obtained was dried in vacuo. The dry residue was
extracted with boiling acetone (200 mL), the insoluble part was
filtered off, whereas gaseous hydrogen chloride was passed
through the filtrate. A precipitate formed was filtered off. The
yield was 1.57 g (31%), a white crystalline compound, m.p. 212—
216 °C (cf. Ref. 33: m.p. 213—216 °C). 1H NMR (DMSOꢀd6), δ:
4.77 (s, 2 H, CH2OH); 6.45 (br.s, 1 H, CH2OH); 7.75 (dd, 1 H,
5ꢀPyH, J1 = 8.4 Hz, J2 = 5.4 Hz); 8.12 (d, 1 H, 4ꢀPyH, J = 8.4 Hz);
8.20 (d, 1 H, 6ꢀPyH, J = 5.4 Hz); 12.36 (br.s, 1 H, OH). 13C NMR
(DMSOꢀd6), δ: 56.22 (s, CH2O); 125.84 (s, CPyr); 129.37 (s, CPyr);
131.16 (s, CPyr); 144.72 (s, CPyr); 153.22 (s, CPyr).
Comꢀ
pound
Saimonella
typhimurium ТА98
Saimonella
typhimurium ТА100
1
10
100
1
10
100
6c
7c
0.87
0.73
0.71 0.89 0.74 0.92
0.66 0.65 1.40 1.33
1.08
0.91
4ꢀNitroquinoꢀ
line Nꢀoxide
Sodium azide
8.20
—
—
6.53
* The excess ratio of the average geometric number of revertants
over control.
3ꢀHydroxyꢀ2,6ꢀbis(hydroxymethyl)pyridine (3). A mixture of
3ꢀhydroxypyridine (10.0 g, 105.3 mmol), sodium hydroxide (4.2 g,
105.0 mmol), and 37% aqueous solution of formaldehyde (39.3 g,
484.7 mmol) in water (50 mL) was heated for 30 h at 90 °C.
Then, the reaction mixture was cooled to ~20 °C and neutralized
by the addition of glacial acetic acid. A solution obtained was
dried in vacuo. The dry residue was extracted with boiling aceꢀ
tone (200 mL), the insoluble part was filtered off, whereas the
filtrate was dried. The residue was recrystallized from methanol.
The yield was 8.70 g (53%), a white crystalline compound, m.p.
137—139 °C (cf. Ref. 34: m.p. 137—138 °C). 1H NMR (DMSOꢀd6),
δ: 4.76 (s, 2 H, CH2OH); 4.77 (s, 2 H, CH2OH); 7.77 (d, 1 H,
4ꢀPyH, J = 8.4 Hz); 8.12 (d, 1 H, 6ꢀPyH, J = 8.7 Hz); 12.11
(br.s, 1 H, OH). 13C NMR (DMSOꢀd6), δ: 55.57 (s, CH2O);
58.63 (s, CH2O); 123.94 (s, CPyr); 130.98 (s, CPyr); 142.87 (s, CPyr);
145.81 (s, CPyr); 152.17 (s, CPyr).
Table 3. Antitumor activity in vitro of monoꢀ and bisphosꢀ
phonium salts against the MCFꢀ7 breast cancer cells
Comꢀ
pound
IC50
/μmol L–1
Comꢀ
pound
IC50
/μmol L–1
6а
6b
6c
6d
6e
7а
7b
7c
7d
339
31.1
3.1
200.0
53.4
25.5
1241
3.7
7e
13а
13b
13c
14а
14b
14c
Doxoꢀ
rubicin
389.9
1139.0
32.2
>24000
205.5
2.8
1532
1.5
265.5
2ꢀChloromethylꢀ3ꢀhydroxypyridine hydrochloride (4). A susꢀ
pension of 3ꢀhydroxyꢀ2ꢀ(hydroxymethyl)pyridine hydrochloride
(2) (5.0 g, 31.0 mmol) in thionyl chloride (30 mL, 646.0 mmol)
was refluxed for 12 h. Then, the reaction mixture was cooled to
~20 °C. A precipitate was filtered off and washed with light
petroleum ether. The yield was 4.60 g (83%), a white crystalline
compound, m.p. 220 °C (decomp.) (cf. Ref. 35: m.p. 160 °C).
1H NMR (DMSOꢀd6), δ: 4.92 (s, 2 H, CH2Cl); 7.74 (ABXꢀsysꢀ
tem, 1 H, 5ꢀPyH, J1 = 8.4 Hz, J2 = 5.2 Hz); 7.97 (ABXꢀsystem,
1 H, 4ꢀPyH, J = 8.4 Hz); 8.30 (ABXꢀsystem, 1 H, 6ꢀPyH, J =
= 5.2 Hz); 12.16 (br.s, 1 H, OH). 13C NMR (DMSOꢀd6), δ:
37.67 (s, CH2Cl); 127.53 (s, CPyr); 130.09 (s, CPyr); 134.12 (s, CPyr);
139.18 (s, CPyr); 154.32 (s, CPyr).
2,6ꢀBis(chloromethyl)ꢀ3ꢀhydroxypyridine hydrochloride (5).
A suspension of 3ꢀhydroxyꢀ2,6ꢀbis(hydroxymethyl)pyridine (3)
(5.0 g, 26.0 mmol) in thionyl chloride (30 mL, 646.0 mmol) was
refluxed for 12 h. Then, the reaction mixture was cooled to
~20 °C. A precipitate was filtered off and washed with light
petroleum ether. The yield was 5.70 g (96%), a white crystalline
compound, m.p. 240 °C (decomp.). 1H NMR (DMSOꢀd6), δ:
4.73 (s, 2 H, CH2Cl); 4.74 (s, 2 H, CH2Cl); 7.46, 7.49 (ABꢀsystem,
2 H, 4ꢀPyH, 5ꢀPyH, J = 8.4 Hz); 11.15 (br.s, 1 H, OH). 13C NMR
(DMSOꢀd6), δ: 41.76 (s, CH2Cl); 45.82 (s, CH2Cl); 124.97 (s, CPyr);
125.65 (s, CPyr); 142.44 (s, CPyr); 145.47 (s, CPyr); 152.30 (s, CPyr).
3ꢀHydroxyꢀ2ꢀ(triphenylphosphoniomethyl)pyridinium dichloꢀ
ride (6a). A solution of triphenylphosphine (0.44 g, 1.67 mmol)
and 2ꢀchloromethylꢀ3ꢀhydroxypyridine hydrochloride (4) (0.15 g,
0.83 mmol) in acetonitrile (20 mL) was refluxed for 4 h. Then,
the solvent was evaporated in vacuo, the dry residue was disꢀ
solved in chloroform and washed with water. The aqueous layer
was separated, dried in vacuo, and recrystallized from acetone.
oxine were synthesized. Some of these compounds possess
pronounced antibacterial and antitumor activity in vitro,
which allows one to consider them as promising comꢀ
pounds in the development of new antibacterial and antiꢀ
tumor agents.
Experimental
Pyridoxine hydrochloride (DSM Nutritional Products),
3ꢀhydroxypyridine (Acros), and phosphines (Acros) were used
without preliminary purification. All the solvents and reagents
were purified and dried according to the standard procedures.32
1H, 13C, 31P, and 19F NMR spectra in CDCl3 or DMSOꢀd6
were recorded on a Bruker Avance 400 spectrometer (400.17,
100.62, 161.99, and 376.54 MHz, respectively). The signals of
the residual nondeuterated chloroform (δ 7.26, δ 77.16) and
H
C
DMSO (δH 2.50, δC 39.52) were used as references in the 1H and
13C NMR spectra, whereas H3PO4 (31P) and CF3Ph (19F) were
used as external standards in the 31P and 19F NMR spectra.
HRMS experiment was carried out using a TripleTOF 5600 mass
spectrometer (AB Sciex, Germany) for the solution in methanol
by turboionic spray ionization (TIS) method with the collision
energy with nitrogen molecules of 10 eV. Melting points of
products were determined using a Stanford Research Systems
MPAꢀ100 OptiMelt appliance.
3ꢀHydroxyꢀ2ꢀ(hydroxymethyl)pyridine hydrochloride (2).
A mixture of 3ꢀ(hydroxymethyl)pyridine (3.00 g, 31.5 mmol),

Phosphonium salts of pyridoxine analogues
Russ.Chem.Bull., Int.Ed., Vol. 65, No. 2, February, 2016
541
The yield was 0.08 g (22%), a white crystalline compound, m.p.
260 °C (decomp.). 1H NMR (DMSOꢀd6), δ: 5.28 (d, 2 H, CH2P,
J = 14.5 Hz); 7.10 (ABXꢀsystem, 1 H, 5ꢀPyH, J1 = 8.3 Hz, J2 =
= 4.7 Hz); 7.28 (ABXꢀsystem, 1 H, 4ꢀPyH, J = 8.3 Hz); 7.67—
7.84 (m, 16 H, 3 Ph + 6ꢀPyH); 10.79 (br.s, 1 H, OH). 13C NMR
system, 1 H, 5ꢀPyH, J1 = 8.0 Hz, J2 = 4.6 Hz); 7.34 (ABXꢀ
system, 1 H, 4ꢀPyH, J = 8.0 Hz); 7.49 (m, 3 H, P(2ꢀthien)3
(thien means thienyl)); 7.91 (ABXꢀsystem, 1 H, 6ꢀPyH, J =
= 4.6 Hz); 7.97 (dd, 3 H, P(2ꢀthien)3, J1 = 8.3 Hz, J2 = 3.4 Hz);
8.45 (t, 3 H, P(2ꢀthien)3, J = 4.6 Hz); 10.83 (s, 1 H, OH). 13C NMR
(DMSOꢀd6), δ: 26.44 (d, CH2P, J = 56 Hz); 119.81 (d, iꢀCAr
J = 87.8 Hz); 122.57 (s, CPyr); 124.25 (s, CPyr); 129.75 (d, mꢀCAr
J = 12.6 Hz); 133.78 (d, oꢀCAr, J = 10.2 Hz); 134.42 (d, pꢀCAr
J = 2.5 Hz); 137.83 (d, CPyr, J = 7.5 Hz); 138.86 (s, CPyr); 152.49
(d, CPyr, J = 7.2 Hz). 31P NMR (DMSOꢀd6), δ: 28.15. HRMS,
found: m/z 370.1356 [M – 2 Cl – H]+. C24H22NOPCl2. Calcuꢀ
lated: [M – 2 Cl – H] = 370.1355.
,
,
,
(DMSOꢀd6), δ: 32.92 (d, CH2P, J = 64.3 Hz); 120.00 (d, Cthien
J = 112.2 Hz); 122.70 (s, CPyr); 124.62 (s, CPyr); 129.99 (d, Cthien
,
,
J = 16.2 Hz); 137.83 (d, Cthien, J = 3.9 Hz); 138.53 (s, CPyr);
140.51 (d, Cthien, J = 4.1 Hz); 141.98 (d, CPyr, J = 12.1 Hz);
152.36 (d, CPyr, J = 8.0 Hz). 31P NMR (DMSOꢀd6), δ: 10.68.
HRMS, found: m/z 388.0048 [M – 2 Cl – H]+. C18H16NOPS3Cl2.
Calculated: [M – 2 Cl – H] = 388.0048.
3ꢀHydroxyꢀ2ꢀ(tributylphosphoniomethyl)pyridinium dichloꢀ
ride (6b). A suspension of 2ꢀchloromethylꢀ3ꢀhydroxypyridine
hydrochloride (4) (0.50 g, 2.78 mmol) and tri(nꢀbutyl)phosphine
(1.37 mL, 5.55 mmol) in acetonitrile (40 mL) was refluxed for
12 h. Then, the solvent was evaporated in vacuo, the dry residue
was recrystallized from acetone. The yield was 0.25 g (24%),
a white crystalline compound, m.p. 159—160 °C. 1H NMR
(CDCl3), δ: 0.87—0.93 (m, 9 H, P(CH2CH2CH2CH3)3); 1.39—
1.53 (m, 12 H, P(CH2CH2CH2CH3)3); 2.34—2.41 (m, 6 H,
P(CH2CH2CH2CH3)3); 4.24 (d, 2 H, CH2P, J = 14.7 Hz); 7.35
(ABXꢀsystem, 1 H, 5ꢀPyH, J1 = 4.3 Hz, J2 = 8.0 Hz); 7.99
(ABXꢀsystem, 1 H, 4ꢀPyH, J = 4.3 Hz); 8.25 (ABXꢀsystem,
1 H, 6ꢀPyH, J = 8.0 Hz). 13C NMR (CDCl3), δ: 13.45
(s, P(CH2CH2CH2CH3)3); 19.82 (d, P(CH2CH2CH2CH3)3,
3ꢀHydroxyꢀ2ꢀ[tris(4ꢀfluorophenyl)phosphoniomethyl]pyriꢀ
dinium dichloride (6e). 2ꢀChloromethylꢀ3ꢀhydroxypyridine hyꢀ
drochloride (4) (0.40 g, 2.22 mmol) was added to a solution of
tris(4ꢀfluorophenyl)phosphine (1.05 g, 3.32 mmol) in acetoniꢀ
trile (40 mL) and the mixture was refluxed for 12 h. Then, the
solution was cooled to ~20 °C and a precipitate was filtered off.
The filtrate was concentrated in vacuo, the dry residue was disꢀ
solved in chloroform and washed with water. The aqueous layer
was separated, dried in vacuo, and recrystallized from acetone.
The yield was 0.09 g (8%), a white crystalline compound, m.p.
232—234 °C. 1H NMR (CDCl3), δ: 5.20 (d, 2 H, CH2P, J =
= 14.1 Hz); 6.94 (ABXꢀsystem, 1 H, 5ꢀPyH, J1 = 8.2 Hz, J2 =
= 4.5 Hz); 7.26—7.34 (m, 6 H, C6H4); 7.55 (ABXꢀsystem, 1 H,
4ꢀPyH, J = 8.2 Hz); 7.73 (ABXꢀsystem, 1 H, 6ꢀPyH, J = 4.5 Hz);
7.75—7.81 (m, 6 H, C6H4); 10.94 (s, 1 H, OH). 13C NMR
(CDCl3), δ: 29.67 (d, CH2P, J = 53.3 Hz); 114.92 (dd, C6H4,
J1 = 92.1 Hz, J2 = 3.2 Hz); 118.13 (dd, C6H4, J1 = 22.1 Hz, J2 =
= 14.2 Hz); 124.82 (s, CPyr); 125.75 (s, CPyr); 136.98 (dd, C6H4,
J1 = 11.8 Hz, J2 = 9.7 Hz); 139.93 (s, CPyr); 153.59 (d, CPyr, J =
= 6.3 Hz); 166.75 (dd, C6H4, J1 = 260.8 Hz, J2 = 3.3 Hz).
31P NMR (CDCl3), δ: 23.32. 19F NMR (CDCl3), δ: –99.63. HRMS,
found: m/z 424.1073 [M – 2 Cl – H]+. C24H19F3NOPCl2. Calcuꢀ
lated: [M – 2 Cl – H] = 424.1073.
3ꢀHydroxyꢀ2,6ꢀbis(triphenylphosphoniomethyl)pyridinium
trichloride (7a). 2,6ꢀBis(chloromethyl)ꢀ3ꢀhydroxypyridine hyꢀ
drochloride (5) (0.20 g, 0.87 mmol) was added to a solution of
triphenylphosphine (1.15 g, 4.39 mmol) in acetonitrile (20 mL)
and the mixture was refluxed for 6 h. Then, a precipitate formed
was filtered off, dissolved in chloroform, and washed with water.
The aqueous part (filtrate) was separated, dried in vacuo, and
washed with acetone. The yield was 0.16 g (24%), a white crysꢀ
talline compound, m.p. 280 °C (decomp.). 1H NMR (DMSOꢀd6),
δ: 4.93 (d, 2 H, CH2P+, J = 15.2 Hz); 5.16 (d, 2 H, CH2P, J =
= 15.7 Hz); 6.99, 7.11 (ABꢀsystem, 2 H, PyH, J = 8.4 Hz);
7.45—7.85 (m, 15 H, 3 Ph); 11.03 (s, 1 H, OH). 13C NMR
(DMSOꢀd6), δ: 26.11 (d, CH2P, J = 50.3 Hz); 29.66 (d, CH2P,
J
=
46.2 Hz); 22.36 (d, CH2P, J
=
47.5 Hz); 23.64
(d, P(CH2CH2CH2CH3)3,
J
=
4.7 Hz); 23.97
(d, P(CH2CH2CH2CH3)3, J = 15.6 Hz); 125.77 (s, CPyr); 128.75
(s, CPyr); 135.49 (s, CPyr); 136.25 (s, CPyr); 155.03 (s, CPyr). 31P NMR
(CDCl3), δ: 35.01. HRMS, found: m/z 310.2294 [M –– 2 Cl – H]+.
C19H35NOPCl2. Calculated: [M – 2 Cl – H] = 310.2294.
3ꢀHydroxyꢀ2ꢀ[tris(pꢀtolyl)phosphoniomethyl]pyridinium
dichloride (6c). 2ꢀChloromethylꢀ3ꢀhydroxypyridine hydrochloꢀ
ride (4) (0.40 g, 2.22 mmol) was added to a solution of trisꢀ
(pꢀtolyl)phosphine (1.01 g, 3.32 mmol) in acetonitrile (40 mL)
and the mixture was refluxed for 12 h. Then, the solvent was
evaporated in vacuo, the dry residue was dissolved in chloroform
and washed with water. The aqueous layer was separated, dried
in vacuo, and recrystallized from acetone. The yield was 0.07 g
(7%), a white crystalline compound, m.p. 152—154 °C. 1H NMR
(DMSOꢀd6), δ: 2.42 (s, 9 H, 3 pꢀMe); 5.13 (d, 2 H, CH2P, J =
= 14.6 Hz); 7.13 (ABXꢀsystem, 1 H, 5ꢀPyH, J1 = 8.2 Hz, J2 =
= 4.6 Hz); 7.29 (ABXꢀsystem, 1 H, 4ꢀPyH, J = 8.2 Hz); 7.48—
7.78 (m, 12 H, 3 C6H4); 7.77 (ABXꢀsystem, 1 H, 6ꢀPyH, J =
= 4.6 Hz); 10.78 (br.s, 1 H, OH). 13C NMR (DMSOꢀd6), δ:
21.20 (s, 3 pꢀMe); 26.37 (d, CH2P, J = 55.7 Hz); 116.48 (d, iꢀCAr
,
J = 90.1 Hz); 121.81 (s, CPyr); 122.87 (s, CPyr); 130.31 (d, mꢀCAr
,
J = 13.0 Hz); 133.64 (d, oꢀCAr, J = 10.6 Hz); 137.53 (s, pꢀCAr);
138.77 (s, CPyr); 145.09 (d, CPyr, J = 2.8 Hz); 152.08 (s, CPyr).
31P NMR (DMSOꢀd6), δ: 22.35. HRMS, found: m/z 412.1825 [M –
– 2 Cl – H]+. C27H28NOPCl2. Calculated: [M – 2 Cl – H] = 412.1825.
3ꢀHydroxyꢀ2ꢀtris[(2ꢀthienyl)phosphoniomethyl]pyridinium
dichloride (6d). 2ꢀChloromethylꢀ3ꢀhydroxypyridine hydrochloꢀ
ride (4) (0.40 g, 2.22 mmol) was added to a solution of trisꢀ
(2ꢀthienyl)phosphine (0.93 g, 3.32 mmol) in acetonitrile (40 mL)
and the mixture was refluxed for 12 h. Then, the solvent was
evaporated in vacuo, the dry residue was dissolved in chloroform
and washed with water. The aqueous layer was separated, dried
in vacuo, and recrystallized from acetone. The yield was 0.24 g
(24%), a white crystalline compound, m.p. 197—198 °C. 1H NMR
(DMSOꢀd6), δ: 5.29 (d, 2 H, CH2P, J = 14.4 Hz); 7.22 (ABXꢀ
J = 48.8 Hz); 118.57 (d, iꢀCAr, J = 86.2 Hz); 118.71 (d, iꢀCAr,
J = 86.1 Hz); 123.57 (s, CPyr); 126.96 (d, CPyr, J = 4.7 Hz);
129.92 (d, mꢀCAr, J = 12.6 Hz); 129.96 (d, mꢀCAr, J = 12.5 Hz);
133.68 (d, oꢀCAr, J = 10.2 Hz); 133.86 (d, oꢀCAr, J = 10.2 Hz);
134.76 (d, pꢀCAr, J = 3.5 Hz); 134.85 (d, pꢀCAr, J = 3.5 Hz);
137.44 (d, CPyr, J = 10.1 Hz); 139.47 (d, CPyr, J = 10.4 Hz);
152.26 (d, CPyr, J = 2.1 Hz). 31P NMR (DMSOꢀd6), δ: 22.62;
23.11. HRMS, found: m/z 322.6170 [M – 3 Cl – H]2+
C43H38NOP2Cl2. Calculated: [M – 3 Cl – H]2+ = 322.6170.
.
3ꢀHydroxyꢀ2,6ꢀbis(tributylphosphoniomethyl)pyridinium
dichloride (7b). A suspension of 2,6ꢀbis(chloromethyl)ꢀ3ꢀhydrꢀ
oxypyridine hydrochloride (5) (0.50 g, 2.18 mmol) and triꢀ
(nꢀbutyl)phosphine (2.16 mL, 8.75 mmol) in acetonitrile (40 mL)
was refluxed for 12 h. Then, the solvent was evaporated in vacuo,

542
Russ.Chem.Bull., Int.Ed., Vol. 65, No. 2, February, 2016
Shtyrlin et al.
the dry residue was recrystallized from diethyl ether. The yield was
0.35 g (25%), a white crystalline compound, m.p. 161—162 °C.
1H NMR (CDCl3), δ: 0.83—0.88 (m, 18 H, 2 P(CH2CH2CH2CH3)3);
1.33—1.54 (m, 24 H, 2 P(CH2CH2CH2CH3)3); 2.28—2.46
(m, 12 H, 2 P(CH2CH2CH2CH3)3); 4.05—4.20 (m, 4 H, 2 CH2P);
7.41 (ABXYꢀsystem, 1 H, 5ꢀPyH, J1 = 7.2 Hz, J2 = 7.2 Hz); 7.99
a solution of tris(4ꢀfluorophenyl)phosphine (1.11 g, 3.48 mmol)
in acetonitrile (40 mL) and the mixture was refluxed for 36 h.
Then, the solution was cooled to ~20 °C and a precipitate was
filtered off. The filtrate was concentrated in vacuo, the dry resiꢀ
due was dissolved in chloroform and washed with water. The
aqueous filtrate was dried in vacuo, and recrystallized from aceꢀ
tone. The yield was 0.05 g (7%), a white crystalline compound,
m.p. 248—250 °C (decomp.). 1H NMR (DMSOꢀd6), δ: 4.95
(d, 2 H, CH2P, J = 15.4 Hz); 5.12 (d, 2 H, CH2P, J = 15.8 Hz);
7.00, 7.12 (ABꢀsystem, 2 H, PyH, J = 8.4 Hz); 7.52—7.78 (m, 24 H,
6 C6H4); 10.97 (s, 1 H, OH). 13C NMR (DMSOꢀd6), δ: 26.44
(d, CH2P, J = 50.6 Hz); 30.04 (d, CH2P, J = 48.1 Hz); 114.60
(d, C6H4, J = 91.0 Hz); 117.49 (d, C6H4, J = 23.0 Hz); 117.60
(dd, C6H4, J1 = 22.1 Hz, J2 = 3.3 Hz); 117.72 (d, C6H4, J = 23.0
(ABXYꢀsystem, 1 H, 4ꢀPyH, J1 = 7.2 Hz, J2 = 8.2 Hz, J3
=
= 8.2 Hz); 11.27 (s, 1 H, OH). 13C NMR (CDCl3), δ: 13.46
(s, 2 P(CH2CH2CH2CH3)3); 19.26 (d, P(CH2CH2CH2CH3)3,
J = 45.6 Hz); 19.38 (d, P(CH2CH2CH2CH3)3, J = 46.3 Hz); 23.62—
23.98 (m, 2 P(CH2CH2CH2CH3)3 + 2 P(CH2CH2CH2CH3)3
+
+ CH2P); 27.86 (d, CH2P, J = 48.3 Hz); 125.43 (s, CPyr); 126.03
(s, CPyr); 138.10 (s, CPyr); 140.38 (s, CPyr); 152.96 (s, CPyr). 31P NMR
(CDCl3), δ: 32.89; 33.71. HRMS, found: m/z 262.7109 [M – 3 Cl –
– H]2+. C31H62NOP2Cl2. Calculated: [M – 3 Cl – H] = 262.7109.
3ꢀHydroxyꢀ2,6ꢀbis[tris(pꢀtolyl)phosphoniomethyl]pyridinium
dichloride (7c). 2,6ꢀBis(chloromethyl)ꢀ3ꢀhydroxypyridine (5)
hydrochloride (0.40 g, 1.75 mmol) was added to a solution
of tris(pꢀtolyl)phosphine (1.60 g, 5.26 mmol) in acetonitrile
(50 mL) and the mixture was refluxed for 12 h. Then, the solvent
was evaporated in vacuo, the dry residue was dissolved in chloroꢀ
form and washed with water. The aqueous filtrate was dried
in vacuo, and washed with acetone. The yield was 0.09 g (6%),
a white crystalline compound, m.p. 162—164 °C. 1H NMR
(DMSOꢀd6), δ: 2.41 (s, 18 H, 6 pꢀMe); 4.81 (d, 2 H, CH2P, J =
= 15.1 Hz); 5.00 (d, 2 H, CH2P+, J = 15.5 Hz); 6.99—7.01 (m, 1 H,
5ꢀPyH); 7.11—7.13 (m, 1 H, 5ꢀPyH); 7.28—7.46 (m, 24 H, 6 C6H4);
10.95 (s, 1 H, OH). 13C NMR (DMSOꢀd6), δ: 21.20 (s, 6 pꢀMe);
26.33 (d, CH2P, J = 51.7 Hz); 29.94 (d, CH2P, J = 49.8 Hz);
115.54 (d, 2 iꢀCAr, J = 88.9 Hz); 122.55 (s, CPyr); 126.87 (s, CPyr);
130.39 (d, mꢀCAr, J = 13.0 Hz); 130.44 (d, mꢀCAr, J = 12.9 Hz);
133.45 (d, oꢀCAr, J = 10.6 Hz); 133.64 (d, oꢀCAr, J = 10.6 Hz);
137.66 (d, pꢀCAr, J = 8.1 Hz); 139.60 (d, pꢀCAr, J = 8.3 Hz);
145.37 (m, CPyr); 152.13 (s, CPyr). 31P NMR (DMSOꢀd6), δ:
Hz); 123.86 (s, CPyr); 127.21 (s, CPyr); 137.22 (dd, C6H4, J1
= 24.3 Hz, J2 = 12.4 Hz); 139.04 (dd, CPyr, J1 = 8.8 Hz, J2
=
=
= 1.7 Hz); 152.45 (m, CPyr); 166.94 (d, C6H4, J = 256.1 Hz).
31P NMR (DMSOꢀd6), δ: 21.54; 21.97. 19F (DMSOꢀd6), δ: –102.09.
HRMS, found: m/z 376.5885 [M – 3 Cl – H]2+. C43H32F6NOP2Cl2.
Calculated: [M – 3 Cl – H] = 376.5887.
5ꢀAcetoxymethylꢀ3ꢀhydroxyꢀ2,4ꢀdimethylpyridinium chloride
(9). Pyridoxine hydrochloride (10.0 g, 48.7 mmol) and activated
zinc dust (13.0 g, 198.8 mmol) were dissolved in glacial acetic
acid (40 mL). The reaction mixture was refluxed for 3 days.
A precipitate was filtered off, the filtrate was concentrated
in vacuo. An oily residue was dried in vacuo and recrystallized
from water. The yield was 4.20 g (36%), a white crystalline comꢀ
pound, m.p. 156—157 °C (cf. Ref. 36: m.p. 180—181 °C). 1H NMR
(DMSOꢀd6), δ: 2.03 (s, 3 H, Me); 2.15 (s, 3 H, Me); 2.36 (s, 3 H,
Me); 5.04 (s, 2 H, CH2O); 7.89 (s, 1 H, CHPyr); 8.80 (s, 1 H,
OH). 13C NMR (DMSOꢀd6), δ: 11.29 (s, Me); 19.82 (s, Me);
20.59 (s, Me); 61.98 (s, CH2O); 128.57 (s, Cpyr); 132.24 (s, Cpyr);
140.50 (s, Cpyr); 146.64 (s, Cpyr); 149.34 (s, Cpyr); 170.19 (s, C=O).
3ꢀHydroxyꢀ5ꢀhydroxymethylꢀ2,4ꢀdimethylpyridinium chloride
(10). Concentrated hydrochloric acid (4.2 mL) was added to
a solution of compound 9 (4.20 g, 20.0 mmol) in water (30 mL)
and the mixture was stirred for 8 h at 50 °C. Then, the solution
was dried in vacuo. The yield was 3.20 g (95%), a white crystalꢀ
line compound, m.p. 252—255 °C (cf. Ref. 37: m.p. 273 °C).
1H NMR (DMSOꢀd6), δ: 2.32 (s, 3 H, Me); 2.62 (s, 3 H, Me);
4.60 (s, 2 H, CH2); 8.07 (s, 1 H, CHPyr). 13C NMR (DMSOꢀd6),
δ: 12.27 (s, Me); 14.92 (s, Me), 58.23 (s, CH2O); 128.49 (s, Cpyr);
138.75 (s, Cpyr); 139.93 (s, Cpyr); 141.70 (s, Cpyr); 151.67 (s, Cpyr).
5ꢀChloromethylꢀ3ꢀhydroxyꢀ2,4ꢀdimethylpyridinium chloride
(11). 3ꢀHydroxyꢀ5ꢀhydroxymethylꢀ2,4ꢀdimethylpyridinium
chloride 10 (3.20 g, 16.9 mmol) and DMF (1 mL) was added to
thionyl chloride (30 mL, 413.0 mmol). The reaction mixture was
refluxed for 5 h. Then, the solution was concentrated in vacuo.
Chloroform was poured to the residue. The undissolved precipiꢀ
tate was filtered off and dried. The yield was 1.85 g (53%),
a brown crystalline compound, m.p. 210—215 °C (cf. Ref. 38:
m.p. 220—225 °C). 1H NMR (DMSOꢀd6), δ: 2.45 (s, 3 H, Me);
2.64 (s, 3 H, Me); 4.96 (s, 2 H, CH2Cl); 8.41 (s, 1 H, CHPyr),
10.93 (s, 1 H, OH). 13C NMR (DMSOꢀd6), δ: 12.90 (s, Me);
15.16 (s, Me); 40.53 (s, CH2Cl); 131.40 (s, Cpyr); 134.13 (s, Cpyr);
142.06 (s, Cpyr); 143.46 (s, Cpyr); 152.52 (s, Cpyr).
21.54; 22.08. HRMS, found: m/z 364.6639 [M – 3 Cl – H]2+
.
C49H51NOP2Cl2. Calculated: [M – 3 Cl – H] = 364.6639.
3ꢀHydroxyꢀ2,6ꢀbis[tris(2ꢀthienyl)phosphoniomethyl]pyriꢀ
dinium dichloride (7d). 2,6ꢀBis(chloromethyl)ꢀ3ꢀhydroxypyridine
hydrochloride (5) (0.20 g, 0.88 mmol) was added to a solution of
tris(2ꢀthienyl)phosphine (0.98 g, 3.50 mmol) in acetonitrile
(40 mL) and the mixture was refluxed for 48 h. Then, the solvent
was evaporated in vacuo, the dry residue was dissolved in chloroꢀ
form and washed with water. The aqueous filtrate was dried
in vacuo, and recrystallized from acetone. The yield was 0.10 g
(15%), a white crystalline compound, m.p. 176—178 °C. 1H NMR
(DMSOꢀd6), δ: 5.00 (d, 2 H, CH2P, J = 15.3 Hz); 5.11
(d, 2 H, CH2P, J = 15.7 Hz); 7.10, 7.34 (ABꢀsystem, 2 H, PyH,
J = 8.4 Hz); 7.47—7.49 (m, 3 H, P(2ꢀthien)3); 7.51—7.53 (m, 3 H,
P(2ꢀthien)3); 7.89 (dd, 3 H, P(2ꢀthien)3, J1 = 8.3 Hz, J2 = 3.6 Hz);
7.97 (dd, 3 H, P(2ꢀthien)3, J1 = 8.3 Hz, J2 = 3.6 Hz); 8.47—8.50
(m, 6 H, P(2ꢀthien)3); 11.33 (s, 1 H, OH). 13C NMR (DMSOꢀd6),
δ: 20.92 (s, CH2P); 25.93 (d, CH2P, J = 54.4 Hz); 119.25 (d, Cthien
J = 86.5 Hz); 123.89 (s, CPyr); 124.71 (s, CPyr); 129.64 (d, Cthien
J = 13.4 Hz); 131.00 (d, Cthien, J = 10.1 Hz); 133.74 (d, Cthien
,
,
,
J = 10.2 Hz); 135.23 (d, Cthien, J = 2.1 Hz); 137.02 (s, CPyr);
138.01 (CPyr); 139.45 (d, Cthien, J = 12.7 Hz); 153.09 (t, CPyr
,
J = 5.1 Hz). 31P NMR (DMSOꢀd6), δ: 4.07; 4.31. HRMS, found:
m/z 340.4863 [M – 3 Cl – H]2+. C31H26NOP2S6Cl2. Calculatꢀ
ed: [M – 3 Cl – H] = 340.4863.
3ꢀHydroxyꢀ2,6ꢀbis[tris(4ꢀfluorophenyl)phosphoniomethyl]ꢀ
pyridinium dichloride (7e). 2,6ꢀBis(chloromethyl)ꢀ3ꢀhydroxypyꢀ
ridine hydrochloride (5) (0.20 g, 0.88 mmol) was added to
3ꢀAcetoxyꢀ5ꢀchloromethylꢀ2,4ꢀdimethylpyridine
(12).
5ꢀChloromethylꢀ3ꢀhydroxyꢀ2,4ꢀdimethylpyridinium chloride
(11) (1 g, 4.81 mmol) was added to anhydrous dichloromethane
(30 mL) with stirring, followed by a sequential addition of triethꢀ
ylamine (1.54 mL, 11.1 mmol) and acetyl chloride (0.44 mL,
6.2 mmol). The reaction mixture was refluxed for 3 h. The soluꢀ

Phosphonium salts of pyridoxine analogues
Russ.Chem.Bull., Int.Ed., Vol. 65, No. 2, February, 2016
543
tion was concentrated to 10 mL and washed with water. The
aqueous filtrate was additionally washed with dichloromethane.
The combined organic solutions were dried in vacuo and purified
by column chromatography (eluent ethyl acetate—dichloꢀ
romethane (1 : 2)). The yield was 0.93 g (90%), a red crystalline
the solution was refluxed for 7 h. Then, the solvent was evapoꢀ
rated in vacuo, the dry residue was washed with light petroleum
ether, the insoluble precipitate was filtered off and recrystallized
from a mixture of chloroform and light petroleum ether. The
yield was 0.46 g (67%), a white crystalline compound, m.p. 226—
228 °C (decomp.). 1H NMR (DMSOꢀd6), δ: 0.89 (t, 9 H,
P(CH2CH2CH2CH3)3, J = 6.2 Hz); 1.26—1.57 (m, 12 H,
P(CH2CH2CH2CH3)3); 2.22—2.39 (m, 6 H, P(CH2CH2CH2CH3)3);
2.44 (s, 3 H, Me); 2.66 (s, 3 H, Me); 4.17 (d, 2 H, CH2P, J =
= 15.5 Hz); 8.39 (s, 1 H, CHPyr); 11.05 (br.s, 1 H, OH). 13C NMR
(DMSOꢀd6), δ: 13.27 (s, PCH2CH2CH2CH3); 14.68 (s, Me);
15.05 (s, Me); 17.51 (d, PCH2CH2CH2CH3, J = 45.9 Hz); 21.26
(d, CH2P, J = 45.1 Hz); 22.67 (d, PCH2CH2CH2CH3, J = 4.1 Hz);
23.39 (d, PCH2CH2CH2CH3, J = 16.0 Hz); 127.04 (d, CPyr, J =
= 7.5 Hz); 132.49 (s, CPyr); 140.35 (br.s, CPyr); 143.52 (br.s,
CPyr); 152.86 (br.s, CPyr). 31P NMR (DMSOꢀd6), δ: 35.59.
HRMS, found: m/z 338.2607 [M – 2 Cl – H]+. C20H38Cl2NOP.
Calculated: [M – 2 Cl – H] = 338.2607.
3ꢀAcetoxyꢀ2,4ꢀdimethylꢀ5ꢀ(triphenylphosphoniomethyl)pyriꢀ
dine chloride (14a). 3ꢀAcetoxyꢀ5ꢀchloromethylꢀ2,4ꢀdimethylpyꢀ
ridine (12) (0.25 g, 1.17 mmol) was added to a solution of triphꢀ
enylphosphine (0.61 g, 2.34 mmol) in acetonitrile (20 mL), the
solution was stirred for 10 h at 55 °C. Then, the solvent was
evaporated in vacuo, the dry residue was washed with diethyl
ether, the insoluble precipitate was filtered off and recrystallized
from acetone. The yield was 0.26 g (46%), a white crystalline
compound, m.p. 244—246 °C (decomp.). 1H NMR (CDCl3), δ:
1.47 (d, 3 H, Me, J = 0.7 Hz); 2.21 (s, 3 H, C(O)Me); 2.22 (d, 3 H,
Me, J = 2.4 Hz); 5.55 (d, 2 H, CH2P, J = 14.3 Hz); 7.55—7.78
(m, 15 H, 3 Ph); 7.98 (d, 1 H, CHPyr, J = 2.7 Hz). 13C NMR
(CDCl3), δ: 12.76 (s, Me); 19.47 (s, Me); 20.41 (s, Me); 25.92
(d, CH2P, J = 47.7 Hz); 117.35 (d, iꢀCAr, J = 85.5 Hz); 122.15
(d, CPyr, J = 8.3 Hz); 130.43 (d, mꢀCAr, J = 12.6 Hz); 134.32
(d, oꢀCAr, J = 10.0 Hz); 135.13 (d, pꢀCAr, J = 2.6 Hz); 141.31
1
precipitate, m.p. 59 °C. H (CDCl3), δ: 2.22 (s, 3 H, Me); 2.37
(s, 3 H, Me); 2.39 (s, 3 H, Me); 4.62 (s, 2 H, CH2); 8.29 (s, 1 H,
CHPyr). 13C NMR (CDCl3), δ: 12.00 (s, Me); 19.65 (s, Me);
20.57 (s, Me); 41.56 (s, CH2); 130.93 (s, Cpyr); 139.44 (s, Cpyr);
145.15 (s, Cpyr); 146.75 (s, Cpyr); 152.12 (s, Cpyr); 168.36 (s, C=O).
HRMS, found: m/z 214.0629 [M + H]. C10H12ClNO2. Calculatꢀ
ed: M = 214.0635.
3ꢀHydroxyꢀ2,4ꢀdimethylꢀ5ꢀ(triphenylphosphoniomethyl)ꢀ
pyridinium dichloride (13a). A. 5ꢀChloromethylꢀ3ꢀhydroxyꢀ2,4ꢀ
dimethylpyridinium chloride (11) (0.35 g, 1.68 mmol) was addꢀ
ed to a solution of triphenylphosphine (0.88 g, 3.36 mmol) in
acetonitrile (20 mL) and the mixture was refluxed for 7 h. Then,
a precipitate was filtered off and washed with acetonitrile. The
yield was 0.45 g (57%), a white crystalline compound, m.p. 303—
305 °C (decomp.). 1H NMR (DMSOꢀd6), δ: 1.62 (s, 3 H, Me);
2.57 (s, 3 H, Me); 5.42 (d, 2 H, CH2P, J = 15.1 Hz); 7.76—7.97
(m, 16 H, 3 Ph + CHPyr); 10.74 (br.s, 1 H, OH). 13C NMR
(DMSOꢀd6), δ: 13.29 (s, Me); 15.52 (s, Me); 23.90 (d, CH2P,
J = 48.3 Hz); 116.78 (d, iꢀCAr, J = 85.7 Hz); 124.78 (d, CPyr
,
J = 7.8 Hz); 130.39 (d, mꢀCAr, J = 12.6 Hz); 132.83 (d, CPyr
,
J = 4.5 Hz); 134.29 (d, oꢀCAr, J = 10.2 Hz); 135.53 (d, pꢀCAr, J =
= 2.0 Hz); 141.74 (br.s, CPyr); 143.56 (d, CPyr, J = 4.4 Hz);
152.55 (d, CPyr, J = 1.4 Hz). 31P NMR (DMSOꢀd6), δ: 23.14.
HRMS, found: m/z 398.1668 [M – 2 Cl – H]+. C26H26Cl2NOP.
Calculated: [M – 2 Cl – H] = 398.1668.
B. 4,5ꢀBis(chloromethyl)ꢀ3ꢀhydroxyꢀ2ꢀmethylpyridinium
chloride (15) (0.50 g, 2.10 mmol) was added to a solution of
triphenylphosphine (2.16 g, 8.25 mmol) in DMF (20 mL), the
solution was refluxed for 7 h. Then, the solvent was removed
in vacuo, the dry residue was dissolved in chloroform and washed
with water, the aqueous filtrate was dried. The product was reꢀ
crystallized from acetone. The yield was 0.60 g (62%).
3ꢀHydroxyꢀ2,4ꢀdimethylꢀ5ꢀ[tris(pꢀtolyl)phosphoniomethyl]ꢀ
pyridinium dichloride (13b). 5ꢀChloromethylꢀ3ꢀhydroxyꢀ2,4ꢀdiꢀ
methylpyridinium chloride (11) (0.30 g, 1.44 mmol) was added
to a solution of tris(pꢀtolyl)phosphine (0.88 g, 2.88 mmol) in
acetonitrile (20 mL), the solution was refluxed for 7 h. Then, the
solvent was evaporated in vacuo, the dry residue was dissolved in
water, the insoluble precipitate was filtered off. The filtrate was
concentrated to dryness. The product was recrystallized from a
mixture of acetone and chloroform. The yield was 0.49 g (66%),
a white crystalline compound, m.p. 289—291 °C (decomp.).
1H NMR (DMSOꢀd6), δ: 1.64 (s, 3 H, Me); 2.46 (s, 9 H, 3 pꢀMe);
2.58 (d, 3 H, Me, J = 1.1 Hz); 5.31 (d, 2 H, CH2P, J = 15.1 Hz);
7.55—7.65 (m, 12 H, 3 C6H4); 7.81 (d, 1 H, CHPyr, J = 2.3 Hz);
10.78 (br.s, 1 H, OH). 13C NMR (DMSOꢀd6), δ: 13.46 (s, Me);
15.44 (s, Me); 21.32 (s, 3 pꢀMe); 24.16 (d, CH2P, J = 49.5 Hz);
113.68 (d, iꢀCAr, J = 88.4 Hz); 125.11 (d, CPyr, J = 7.5 Hz);
130.92 (d, mꢀCAr, J = 13.0 Hz); 132.73 (d, CPyr, J = 6.7 Hz);
(d, CPyr, J = 5.1 Hz); 144.97 (d, CPyr, J = 3.4 Hz); 148.29 (d, CPyr
,
J = 5.2 Hz); 151.38 (d, CPyr, J = 4.0 Hz); 167.98 (s, C(O)Me).
31P NMR (CDCl3), δ: 22.62. HRMS, found: m/z 440.1774
[M – Cl]+. C28H27ClNO2P. Calculated: [M – Cl] = 440.1774.
3ꢀAcetoxyꢀ2,4ꢀdimethylꢀ5ꢀ{tris(pꢀtolyl)phosphoniomethyl]ꢀ
pyridine chloride (14b). 3ꢀAcetoxyꢀ5ꢀchloromethylꢀ2,4ꢀdimethꢀ
ylpyridine (12) (0.20 g, 0.94 mmol) was added to a solution of
tris(pꢀtolyl)phosphine (0.57 g, 1.87 mmol) in acetonitrile (20 mL),
the solution was stirred for 10 h at 55 °C. Then, the solvent was
evaporated in vacuo, the dry residue was washed with diethyl
ether, the insoluble precipitate was filtered off and recrystallized
from acetone. The yield was 0.39 g (80%), a white crystalline
compound, m.p. 253—255 °C (decomp.). 1H NMR (CDCl3),
δ: 1.60 (br.s, 3 H, Me); 2.26 (s, 3 H, C(O)Me); 2.28 (d, 3 H, Me,
J = 2.2 Hz); 2.43 (s, 9 H, 3 pꢀMe); 5.30 (d, 2 H, CH2P, J =
= –13.7 Hz); 7.39—7.56 (m, 12 H, 3 C6H4); 7.91 (d, 1 H,
CHPyr, J = 2.5 Hz). 13C NMR (CDCl3), δ: 13.06 (s, Me); 19.52
(s, Me); 20.51 (s, Me); 21.95 (s, 3 pꢀMe); 26.56 (d, CH2P, J =
49.3 Hz); 114.19 (d, iꢀCAr, J = 88.4 Hz); 122.70 (d, CPyr, J = 8.3 Hz);
131.24 (d, mꢀCAr, J = 13.0 Hz); 134.23 (d, oꢀCAr, J = 10.3 Hz);
141.67 (d, CPyr, J = 5.0 Hz); 145.20 (d, CPyr, J = 3.2 Hz); 146.53
134.10 (d, oꢀCAr, J = 10.6 Hz); 141.62 (s, CPyr); 143.66 (d, CPyr
,
J = 4.3 Hz); 146.36 (d, pꢀCAr, J = 2.7 Hz); 152.54 (s, CPyr). 31P NMR
(DMSOꢀd6), δ: 22.51. HRMS, found: m/z 440.2138 [M – 2 Cl –
H]+. C29H32Cl2NOP. Calculated: [M – 2 Cl – H] = 440.2138.
3ꢀHydroxyꢀ2,4ꢀdimethylꢀ5ꢀ(tributylphosphoniomethyl)pyriꢀ
dinium dichloride (13c). Tri(nꢀbutyl)phosphine (1.26 mL, 5.05 mmol)
and 5ꢀchloromethylꢀ3ꢀhydroxyꢀ2,4ꢀdimethylpyridinium chloꢀ
ride (11) (0.35 g, 1.68 mmol) were added to acetonitrile (20 mL),
(d, pꢀCAr, J = 2.8 Hz); 148.02 (d, CPyr, J = 5.0 Hz); 151.37 (d, CPyr,
J = 3.7 Hz); 168.07 (s, C(O)Me). 31P NMR (CDCl3), δ: 21.65.
HRMS, found: m/z 482.2243 [M – Cl]+. C31H33ClNO2P. Calꢀ
culated: [M – Cl] = 482.2243.
3ꢀAcetoxyꢀ2,4ꢀdimethylꢀ5ꢀ(tributylphosphoniomethyl)pyriꢀ
dine chloride (14c). Tri(nꢀbutyl)phosphine (0.58 mL, 2.34 mmol)
and compound 12 (0.25 g, 1.17 mmol) were added to acetoniꢀ

544
Russ.Chem.Bull., Int.Ed., Vol. 65, No. 2, February, 2016
Shtyrlin et al.
trile (20 mL), the solution was stirred for 10 h at 55 °C. Then, the
solvent was evaporated in vacuo, the dry residue was washed
with light petroleum ether. The yield was 0.41 g (84%), a white
crystalline compound, m.p. 168—170 °C (decomp.). 1H NMR
(CDCl3), δ: 0.89 (t, 9 H, P(CH2CH2CH2CH3)3, J = 6.8 Hz);
1.32—1.53 (m, 12 H, P(CH2CH2CH2CH3)3); 2.33 (s, 3 H,
C(O)CH3); 2.34 (d, 3 H, Me, J = 2.3 Hz); 2.36 (d, 3 H, Me, J =
= 0.8 Hz); 2.41—2.48 (m, 6 H, P(CH2CH2CH2CH3)3); 4.40
(br.s, 2 H, CH2P); 8.19 (d, 1 H, CHPyr, J = 2.4 Hz). 13C NMR
(CDCl3), δ: 13.45 (s, PCH2CH2CH2CH3); 14.29 (s, Me); 18.90 (d,
PCH2CH2CH2CH3, J = 46.0 Hz); 19.48 (s, Me); 20.52 (s, Me);
22.65 (d, CH2P, J = 45.7 Hz); 23.80 (d, PCH2CH2CH2CH3, J =
= 4.9 Hz); 24.13 (d, PCH2CH2CH2CH3, J = 15.4 Hz); 123.60
The broth (100 μL) was placed in the wells of each plate. In
the first well, 100 μL of a test compound in a concentration of
2000 μg mL–1 were placed and by the sequential twoꢀfold diluꢀ
tion its concentration was brought to 0.5 μg mL–1. Then, a
a prepared inoculum was added to each well, thus decreasing
twoꢀfold the concentration of the test compounds. The wells
containing no test compound were included as controls (culture
growth control). The purity of nutrient media and solvents was
controlled in each experiment. The plates were incubated in a
thermostat for 24 h at 36 °C. The culture growth was evaluated
using a Multiskan FC photometer, comparing the growth of miꢀ
croorganisms in the presence of a test compound with the culꢀ
ture growth without them.
(d, CPyr, J = 8.2 Hz); 140.50 (d, CPyr, J = 4.7 Hz); 145.69 (d, CPyr
,
Determination of mutagenicity. The auxotrophic for histidine
strains Salmonella typhimurium TA98 and Salmonella typhimuriꢀ
um TA100 were used as the indicator microorganisms. The presꢀ
ence of the mutagenic action in the agent was inferred from the
induction of reverse mutations from the auxotrophy for histidine
to the prototrophy. The testing was carried out according to
a traditional scheme without a microsomal fraction. Distilled
water was used as a negative control, 4ꢀnitroquinoline Nꢀoxide
in a concentration of 10 μg dish–1 and sodium azide in a concenꢀ
tration of 1.5 μg dish–1 were used as a positive control for the
strain Salmonella typhimurium TA98 and Salmonella typhimuriꢀ
um TA100, respectively. The concentration of a compound unꢀ
der study in the test system was 100, 10, and 1 μg mL–1. The
results were assessed according to the algorithm described earliꢀ
er.39 For each variant, an average geometric number of reverꢀ
tants was calculated and the excess ratio of the average geometꢀ
ric number of revertants in the experiment over control was
found. The presence of mutagenicity was registered at the excess
ratio of 1.5 for the strains Salmonella typhimurium TA98 and
Salmonella typhimurium TA100).40
Determination of cytotoxicity. The breast cancer cells MCFꢀ7
(ATCC® HTBꢀ22™) were cultured in the medium αꢀMeM
(PanEko, Russia) with the addition of 10% fetal calf serum (PAA,
Australia), Lꢀglutamine, and 1% penicillin—streptomycin in the
CO2 atmosphere (5%) at 37 °C to the formation of a monolayer.
To prepare the cell suspension, the cell monolayer was
trypsinized with subsequent inactivation of the trypsin by the
addition of the αꢀMeM medium with the serum. Then, the cells
were precipitated by centrifugation at 500 g. The precipitate was
resuspended in the phosphate buffered saline. Evaluation of viaꢀ
bility and calculation of density were performed after the cells
were colored with 0.4% solution of trypan blue in a Neubauer
haemocytometer chamber. Suspensions with the amount of viaꢀ
ble cells ≥90% were used in the experiment.
J = 2.8 Hz); 147.45 (d, CPyr, J = 4.6 Hz); 151.59 (d, CPyr, J = 3.5 Hz);
168.22 (s, C(O)CH3). 31P NMR (CDCl3), δ: 34.39. HRMS,
found: m/z 380.2713 [M – Cl]+. C22H39ClNO2P. Calculated:
[M – Cl] = 380.2713.
4,5ꢀBis(dichloromethyl)ꢀ3ꢀhydroxyꢀ2ꢀmethylpyridinium chloꢀ
ride (15). Pyridoxine hydrochloride (20.0 g, 0.10 mol) and DMF
(5 mL) were added to dichloromethane (200 mL). Then, thionyl
chloride (24 mL, 0.33 mol) was added to the mixture with conꢀ
tinuous stirring over 10 min. The reaction mixture was refluxed
for 12 h. A precipitate was filtered off and washed with dichloꢀ
romethane. The yield was 22.6 g (96%), a white crystalline comꢀ
pound, m.p. 203—204 °C (decomp.) (cf. Ref. 30: m.p. 203 °C).
1H NMR (DMSOꢀd6), δ: 2.66 (s, 3 H, Me); 4.98 (s, 2 H, CH2Cl);
5.01 (s, 2 H, CH2Cl); 8.44 (s, 1 H, CHPyr). 13C NMR (DMSOꢀ
d6), δ: 16.03 (s, Me); 35.27 (s, CH2Cl); 39.31 (s, CH2Cl); 133.14
(s, Cpyr); 133.69 (s, Cpyr); 138.39 (s, Cpyr); 144.84 (s, Cpyr); 152.48
(s, Cpyr).
Studies of antibacterial activity. The minimum inhibiting conꢀ
centration was determined as described earlier.39 The following
gramꢀpositive strains were used: Staphylococcus aureus ATCC
29213, Staphylococcus epidermis (clinical isolate, Kazan Scienꢀ
tific Research Institute of Epidemiology and Microbiology, Kaꢀ
zan, Russian Federation), Bacillus subtilis (Museum of the Miꢀ
crobiology Department of the Kazan Federal University, Kaꢀ
zan, Russian Federation); as well as the gramꢀnegative strains
Escherichia coli ATCC 25922, Pseudomonas aeroginosa ATCC
27853, Klebsiella pneumoniae (clinical isolate, Kazan Scientific
Research Institute of Epidemiology and Microbiology, Kazan,
Russian Federation).
Comparative evaluation of antibacterial action was carried
out using a micromethod for the determination of minimum
inhibiting concentration (MIC) by the serial dilution method in
broth, using 96ꢀwell sterile plates. The starting solution of test
compounds were prepared in a concentration of 2000 μg mL–1
.
The sensitivity of the tumor cells MCFꢀ7 with respect to
synthesized compounds was evaluated using a proliferative
MTTꢀtest (3ꢀ(4,5ꢀdimethylthiazolꢀ2ꢀyl)ꢀ2,5ꢀdiphenyltetrazolꢀ
ium bromide) (Promega, USA).
The first lowest concentration of a test compound (from the
series of sequential dilutions), where no bacterial growth was
visually determined, was considered as the minimum inhibiting
concentration. A broth and a bacterial culture growth control
were present in each experiment.
A pure, daily culture of microorganisms grown on a solid
nutrient medium was used for the preparation of inoculum.
A suspension of microorganisms was prepared in a sterile isotonic
solution of sodium chloride, bringing the inoculum density to 0.5
according to the McFarland standard (1.5•108 CFU mL–1). Then,
the inoculate was diluted to the concentration of 1•107 CFU mL–1
with a nutrient broth. The inoculum was used during 15 min
after the preparation. The purity of bacterial strains was moniꢀ
tored before each experiment.
The cells (2000 cells in a well) were cultured in a nutrient
medium (180 μL) according to the standard culturing conditions
in a 96ꢀwell plate for 1 day. Then, a test agent (20 μL) was added
and this was incubated for 72 h under standard conditions. Then,
the medium with the agents was exchanged for the nutrient meꢀ
dium (80 μL), the MTTꢀreagent (20 μL, 5 mg mL–1) was added,
and this was incubated for 3.5 h. Then, the medium was removed
and DMSO (100 μL) was added. After 10 min, optical density of
the cell solutions was measured at 555 nm (the reference waveꢀ
length 650 nm) on a TECAN plate reader (Switzerland). The
results were presented in the percent ratio to the control sample,

Phosphonium salts of pyridoxine analogues
Russ.Chem.Bull., Int.Ed., Vol. 65, No. 2, February, 2016
545
treated with no agents. The curve of the dose—effect depenꢀ
dence was plotted for the agents and the values IC50 (P < 0.05)
were determined.
21. A. Taladriz, A. Healy, E. J. F. Perez, V. H. Garcha, C. R. Marth-
nez, A. A. M. Alkhaldi, A. A. Eze, M. Kaiser, H. P. de Koning,
A. Chana, C. Dardonville, J. Med. Chem., 2012, 55, 2606.
22. L. T. Archipova, M. M. Archipova, L. E. Bakeeva, A. Zh.
Fursova, E. N. Grigorian, A. Yu. Grishanova, E. N. Iomdiꢀ
na, Zh. N. Ivashchenko, L. A. Katargina, O. V. Kilina, N. G.
Kolosova, E. P. Kopenkin, N. A. Kovaleva, V. V. Neroev, Y. P.
Novikova, P. P. Philippov, O. V. Rubtsova, V. B. Saprunoꢀ
va, I. I. Senin, M. V. Skulachev, L. F. Sotnikova, N. K.
Tikhomirova, N. A. Trofimova, I. P. KhoroshilovaꢀMasloꢀ
va, I. V. Tsapenko, A. I. Shchipanova, V. P. Skulachev, Bioꢀ
chem. (Moscow), 2008, 73, 1317 [Biokhim. (Moscow), 2008,
73, 1641].
23. E. V. Yani, L. A. Katargina, N. B. Chesnokova, O. V. Beznos,
A. Yu. Savchenko, V. A. Vygodin, E. Yu. Gudkova, A. A.
Zamyatnin, M. V. Skulachev, Prakt. med. [Pract. Med.],
2012, 1, No. 59, 134 (in Russian).
24. M. V. Pugachev, N. V. Shtyrlin, E. V. Nikitina, L. P. Sysoꢀ
eva, T. I. Abdullin, A. G. Iksanova, A. A. Ilaeva, E. A. Berdꢀ
nikov, R. Z. Musin, Yu. G. Shtyrlin, Bioorg. Med. Chem.,
2013, 21, 4388.
25. M. V. Pugachev, N. V. Shtyrlin, S. V. Sapognikov, L. P.
Sysoeva, A. G. Iksanova, E. V. Nikitina, R. Z. Musin, O. A.
Lodochnikova, E. A. Berdnikov, Yu. G. Shtyrlin, Bioorg.
Med. Chem., 2013, 21, 7330.
26. N. V. Shtyrlin, A. D. Strel´nik, L. P. Sysoeva, O. A. Lodochꢀ
nikova, E. N. Klimovitskii, Yu. G. Shtyrlin, Russ. J. Org.
Chem. (Engl. Transl.), 2009, 45, 1266 [Zh. Org. Khim., 2009,
45, 1274].
27. N. V. Shtyrlin, O. A. Lodochnikova, M. V. Pugachev, T. I.
Madzhidov, L. P. Sysoeva, I. A. Litvinov, E. N. Klimovꢀ
itskii, Yu. G. Shtyrlin, Russ. J. Org. Chem. (Engl. Transl.),
2010, 46, 561[Zh. Org. Khim., 2010, 46, 569].
28. N. V. Shtyrlin, R. S. Pavelyev, M. V. Pugachev, L. P. Sysoꢀ
eva, R. Z. Musin, Yu. G. Shtyrlin, Tetrahedron Lett., 2012,
53, 3967.
29. A. U. Ziganshin, O. S. Kalinina, A. D. Strelnik, M. R. Gariꢀ
pov, S. A. Koshkin, L. E. Ziganshina, Yu. G. Shtyrlin, Int. J.
Pharmacol., 2015, 11, 400.
30. R. Serwa, T.ꢀG. Nam, L. Valgimigli, S. Culbertson, C. L.
Rector, B.ꢀS. Jeong, D. A. Pratt, N. A. Porter, Chem. Eur.
J., 2010, 47, 14106.
31. K. DongꢀGuk, K. Youra, L. Hyunji, L. E. Kyung, N. TaeꢀGyu,
K. JungꢀAe, J. ByeongꢀSeon, Eur. J. Med. Chem., 2014, 78, 126.
32. A. Weisberger, Organic Solveents. Physical Properties and
Methods of Purification, International Publishers, New York,
1955, 372 pp.
33. Y. Murakami, J. Sunamoto, H. Sadamori, H. Kondo, M. Takꢀ
agi, Bull. Chem. Soc. Jpn, 1970, 43, 2518.
34. R. Kuhn, H. R. Hensel, Chem. Ber., 1953, 86, 1333.
35. T. L. Gilkrist, G. M. Iskander, A. K. Yagoub, J. Chem. Soc.,
Chem. Commun., 1981, 696.
36. R. F. Lonq, A. L. Morrison, J. Chem. Soc., 1954, 3854.
37. R. G. Taborsky, J. Org. Chem., 1960, 26, 596.
38. E. Wilson, M. Tishler, J. Am. Chem. Soc., 1951, 73, 3635.
39. A. N. Mironov, Rukovodstvo po provedeniyu doklinicheskikh
issledovanii lekarstvennykh sredstv [Manual on Conducting
Preclinical Studies of Medicines], P. 1, Grif i K, Moscow,
2012, 944 pp. (in Russian).
The work was funded by the subsidy allocated to the
Kazan Federal University for the Project part of the State
Assignment in the Sphere of Scientific Activities and by
the Russian Foundation for Basic Research (Project No.
14ꢀ03ꢀ31064).
References
1. C. L. Zhu, Angew. Chem., Int. Ed., 2011, 50, 5869.
2. D. Uraguchi, Synlett., 2011, 9, 1265.
3. H. Fujioka, Angew. Chem., Int. Ed., 2011, 50, 12232.
4. J. Emsley, The Chemistry of Phosphorus, Harper and Row,
London, 1976, 560 p.
5. E. Zbiral, Organophosphorus Reagents in Organic Synthesis,
Academic Press, London, 1979, 608 pp.
6. D. Cao, Z. Chai, J. Zhang, Z. Ye, H. Xiao, H. Wang, J. Chen,
X. Wua, G. Zhao, Chem. Commun., 2013, 49, 5972.
7. H. Lund, J. Harloff, A. Schulz, A. Villinger, Z. Anorg. Allg.
Chem., 2013, 639, 754.
8. A. M. A. Dias, S. Marceneiro, M. E. M. Braga, J. F. J.
Coelho, A. G. M. Ferreira, P. N. Simxes, H. I. M. Veiga,
L. C. Tome, I. M. Marrucho, J. M. S. S. Esperanca, A. A.
Matias, C. M. M. Duarte, L. P. N. Rebelo, H. C. de Sousa,
Acta Biomater., 2012, 8, 1366.
9. C. J. Meyer, M. Vogt, J. P. Catalino, B. L. Ashfeld, Synlett.,
2013, 24, 1428.
10. J. J. Tindale, K. L. Mouland, P. J. Ragogna, J. Mol. Liq.,
2010, 152, 14.
11. H. Bestmann, K. H. Büchel, J. Houben, E. Müller, M. Reꢀ
gitz, T. Weyl, Organische Phosphorverbindungen 1, Thieme,
Stuttgart, 1982, 972 pp.
12. D. Purdela, R. Volceanu, Chimia compusilor organici ai fosfoꢀ
rului si ai acizilor lui, Editura Academiei Republicii Socialꢀ
iste Romania, Romania, 1965, 539.
13. L. Kasukhin, V. Brovarets, O. Smolii, V. Kurg, L. Budnik,
B. S. Drach, J. Gen. Chem. (Engl. Transl.), 1991, 61, 2679
[Zh. Obshch. Khim, 1991, 61, 2679].
14. P. McAllister, M. Dotson, S. Grim, G. Hillman, J. Med.
Chem., 1980, 23, 862.
15. D. C. Rideout, T. Calogeropoulou, J. S. Jaworski, R. J. Dagniꢀ
no, M. R. McCarthy, AntiꢀCancer Drug Design., 1989, 4, 265.
16. G. V. Romanov, O. K. Pozdeev, G. Kh. Gil´manova, T. Ya.
Ryzhikova, E. P. Semkina, Pharmaceut. Chem. J., 1990,
24, 414.
17. US Pat. 4297487, 1981; http://patft.uspto.gov/netacgi/nphꢀ
Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=/netahtꢀ
ml/PTO/searchꢀbool.html&r=1&f=G&1=50&d=
PALL&RefSrch=yes&Query=PN/4297487.
18. I. Galkina, Yu. Bakhtiyarova, V. Andriyashin, V. Galkin,
R. Cherkasov, Phosph. Sulf. Silicon, 2013, 188, 15.
19. A. Kanazava, T. Ikeda, T. Endo, Antimicrob. Agents Chemoꢀ
ther., 1994, 38, 945.
20. JP Pat. 2005060332, 2005; https://www19.jꢀplatpat.inpit.go.jp/
PA1/cgiꢀbin/PA1DETAIL?MaxCount=1000&PageCount=
1000&SearchType=0&TempName=wLꢀadya&MaxPage=
1 & D i s p P a g e = 1 + 1 0 0 0 & H i t C o u n t = 1 & R e s u l t I d =
I00222005801&CookieId=2&DetailPage=1&Language=
ENG&Reserve1=DetailPaging&Reserve2=Ky2ZA2759_
FS086H62eK&Reserve3=.
40. D. Maron, B. Ames, Mutation Res., 1983, 113, 173.
Received May 5, 2015