Reaction of Potassium Salts of N-(Thio)phosphorylthioamides with Chlorinated 1,3,5-Triazines

Article abstract of DOI:10.1023/A:1025617309594

Potassium salts of N-(thio)phosphorylthioamides can substitute one, two, or three halogen atoms in chlorinated 1,3,5-triazine molecules to give the products of imidothiyl structure. At low temperature, products of incomplete substitution of halogen in the

Full text of DOI:10.1023/A:1025617309594

Russian Journal of General Chemistry, Vol. 73, No. 4, 2003, pp. 638 642. Translated from Zhurnal Obshchei Khimii, Vol. 73, No. 4, 2003,
pp. 676 680.
Original Russian Text Copyright
2003 by Zabirov, Sokolov, Cherkasov.
Reaction of Potassium Salts of N-(Thio)phosphorylthioamides
with Chlorinated 1,3,5-Triazines
N. G. Zabirov, F. D. Sokolov, and R. A. Cherkasov
Kazan State University, Kazan, Tatarstan, Russia
Received March 23, 2001
Abstract Potassium salts of N-(thio)phosphorylthioamides can substitute one, two, or three halogen atoms
in chlorinated 1,3,5-triazine molecules to give the products of imidothiyl structure. At low temperature,
products of incomplete substitution of halogen in the starting 1,3,5-triazines can be obtained.
We have shown previously [1, 2] that N-(thio)-
phosphorylated thioamides and their potassium salts
are readily and selectively alkylated with alkyl halides
with the transfer of the reaction center to the sulfur
atom of the thiocarbonyl group, which allows prepara-
tion of a great variety of various S-functionalized
derivatives of N-(thio)phosphorylthioamides [3 5].
This induced us to study substitution of chlorine
atoms at the sp2-hybridized carbon atom in chlori-
nated derivatives under the action of potassium salts
II with the aim to obtain compounds exhibiting high
biological activity due to the presence of the 1,3,5-tri-
azine ring and N-(thio)phosphorylimidothioate group,
the groups with pronounced potential biogenic
properties. Synthesis of 1,3,5-triazine derivatives
containing N-thiophosphorylurea or carbamate frag-
ment was reported previously. These compounds were
prepared by the reaction of bis- or monoamino-
substituted derivatives of 1,3,5-triazine [6] or hydroxy-
substituted derivatives of ethylamino- and ethylhyd-
razino-1,3,5-triazine [7] with phosphoryl isocyanates.
R2
R2
X
N
N
X
O
N
N
+ O=C=N P(OEt)2
NH C NH P(OEt)2
III
R1
NH2
R1
N
N
Cl
Cl
N
X
R2 R3
N
X
O
N
N
N
+ O=C=N P(OEt)2
R1
NH CH CH O C NH P(OEt)2
R1
N
NH CH CH OH
R3
IV
R2
The resulting substituted ureas III and urethanes
IV, as well as their isothiouronium salts, exhibit high
herbicidal activity [8 10].
dioxane. The products were purified by passing
through a column packed with alumina (Brockmann
grade II). The IR and 31P NMR data for the com-
pounds obtained are listed in the table.
We studied the reactions of potassium salts of N-di-
isopropoxythiophosphorylthiobenzamide IIa (X = S)
and N-diisopropoxyphosphorylthiobenzamide IIb
(X = O) with 2,4,6-trichloro-1,3,5-triazine (cyanuric
acid chloride) V, 2-methoxy-4,6-dichloro-1,3,5-tri-
azine VI, and 2,4-dimethoxy-6-chloro-1,3,5-triazine
VII, which readily occur in anhydrous acetone or
The reactions of potassium salts of N-diisopropoxy-
(thio)phosphorylthiobenzamide with cyanuric acid
chloride V may yield mono-, di-, and trisubstituted
products VIII X. When performed at 0 C at the 1:1
ratio of the starting compounds, the reaction yielded
disubstituted cyanuric acid chloride derivatives. The
1070-3632/03/7304-0638$25.00 2003 MAIK Nauka/Interperiodica

REACTION OF POTASSIUM SALTS OF N-(THIO)PHOSPHORYLTHIOAMIDES
639
Spectral and physical characteristics of imidoyl-substituted 1,3,5-triazines IX XIV
R2
N
N
R1
N
R3
1
IR spectrum, , cm
POC
31P NMR
spectrum,
C=N JP, ppm
Comp.
no.
Yield,
%
R1
R2
R3
n2D0
P=X
triazine
IXa
Z1 a
Z1
Z1
Cl
Cl
78.0
74.6
1.5764 620, 650 1010 1070 br.v.s,
1110
1.5770 620, 650 1010 1070 br.v.s,
1540,
1620
1620
56
56
w
1560
1540,
1560
1550 br.s 1615
1540,
IXab
Z1
w
1110
IXb
Xa
Z2
Z1
Z2
Z1
Cl
Z1
61.0
57.4
1.6804c
1.5970
1245
970 1000 br.v.s
8
56
620 650 980 1070 br.v.s,
1620
br.w
1245
1120
1000 1070 br.v.s,
1120
1560
1540,
1560
1560,
1540 vs.s
1525,
1500 vs.s
Xb
XI
Z2
Z2
Z1
Z1
Z1
Z2
Cl
49.0
63.0
58.0
10.0
1.6428
1620
3
62
54
54
58
OCH3
OCH3
1.6373
620 655 1000 1070 br.v.s,
br.w 1120
620 br.w 960 1000 br.v.s,
1100
625, 650 1000, 1010
w
1620 s
1660 s
d
XII
Z1
OH
XIIIe OCH3
XIV OCH3
1550 br.s 1675
d
d
OCH3 Z1
24.0
625 br.w 980 1000
1560 br.s 1610
a
1
2
b
Z
= S C(Ph)=N P(S)(O Pr-i) ; Z = S C(Ph)=N P(O)(OPr-i) . The product was isolated from the reaction of cyanuric acid
2
2
c
chloride with the potassium salt of thioamide IIa in 1:1 molar ratio. Yield based on IIa. The refractive index was measured at
25 C.
d
e
1
The refractive undex could not be measured.
(NH/OH) 3100 3400 cm , br.
resulting bright violet liquid products were identified
by IR and 31P NMR spectroscopy and elemental
analysis as N-(thio)phosphorylthiobenzimidates IX.
When performed at the 1:3 ratio of the starting
products with refluxing, the reaction yielded trisub-
stituted products X. These compounds are dark red
liquids. The structures of compounds X and their
compositions were determined spectroscopically (see
table) and by elemental analysis.
Cl
Potassium salts of N-(thio)phosphorylthiobenz-
amides react with cyanuric acid chloride with the
participation of the thiocarbonyl atom to give the
products of the imidothiyl structure, which is con-
firmed by the presence in the IR spectra of IX and X
N
N
+ Ph C N P(OPr-i)2
Cl
Cl
N
S
Y
K+
IIa (Y = S), IIb (Y = O)
1
of the absorption band at 1600 1675 cm , charac-
1:1 or 1:2
1:3
1:1
teristic of the stretching vibrations of the C=N bond.
The 31P NMR signals in these compounds are ob-
served at 8 (IXb) and 3 ppm (Xb), or at 56 ppm
(IXa, Xa), which indicates that the corresponding
compounds have the amidophosphate (X = O) or
amidothiophosphate (X = S) structure.
N
N
N
Z
Z
Z
Cl
Z
Z
N
N
N
N
N
N
Cl
Cl
Z
VIII
IXa, IXb
Xa, Xb
A more complex pattern was observed in the reac-
tion of salt IIa with mono- and dimethoxy derivatives
of cyanuric acid chloride. Introduction of one or two
electron-donating methoxy groups negatively affects
Z = S C(Ph)=N P(S)(OPr-i)2 (a),
S C(Ph)=N P(O)(OPr-i)2 (b).
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 4 2003

640
ZABIROV et al.
the stability of the resulting products. The reaction
with methoxy derivative VI is nonselective and yields
a mixture of products susceptible to hydrolysis, which
complicates their separation. The 31P NMR spectrum
of the reaction mixture, along with the signals indi-
cative of the amidophosphate surrounding of phos-
phorus, contains the signals of by-products of un-
known structure at 71 and 86 ppm. Formation of these
compounds presumably involves migration of the
thiophosphoryl group, but we failed to identify these
compounds and to elucidate the reaction pathway. We
isolated and characterized only the products of
chlorine substitution having the imidothiyl structure.
column packed with alumina gives 2-methoxy-4-(N-di-
isopropoxythiophosphoryl-S-thiobenzimidoyl)-6-
hydroxy-1,3,5-triazine XIII as a cherry red oil with
54 ppm. The presence of the absorption bands aPt
1
1725 cm related to C=O vibrations and of the band
1
at 1675 cm related to the C=N group suggests the
presence of two tautomeric forms A and B of the
hydrolysis product XIII. Also, the IR spectrum con-
tains the bands of the other functional groups ( ,
1
cm ): 3100 3400 br (OH, NH), 1550 1570 (triazine),
1000, 1010 (POC), 625, 650 w (P=S). Evidenly, com-
pound XIII is formed by the reaction of disubstituted
triazine XII with water adsorbed on alumina.
The reaction of thioamide IIa with 2-methoxy-4,6-
dichloro-1,3,5-triazine VI at room temperature leads
to the substitution of one chlorine atom. The product
XI isolated by passing through the column packed
with alumina contains a singlet at 62 ppm in the 31P
NMR spectrum, indicative of the amidothiophosphate
structure. The absorption bands of triazine and imido-
OH
N
N
[H2O]
S
R
XII
S C=N P(OC3H7-i)2
CH3O
N
XIII
+ R C NH P(OC3H7-i)2
1
thiyl fragments ( , cm ) are observed at 1620 v.s
S
S
Ia
(C N), 1560, 1540 v.s (triazine), 1000 1070,
1120 br.v.s (POC), and 620 655 br.w (P=S). These
data confirm the structure of the product. The N H
OH
1
absorption band at 3000 3400 cm is absent.
N
N
S
R
Heating of dichloride VI with two equivalents of
potassium salt IIa leads to the substitution of two
chlorine atoms in the starting triazine. By column
chromatography on alumina, we isolated 2-methoxy-
4,6-(S-isothiobenzamido-N-diisopropoxythiophos-
phoryl)-1,3,5-triazine XII. Its IR spectrum contains
S C=N P(OC3H7-i)2
CH3O
N
A
O
H
N
N
S
R
S C=N P(OC3H7-i)2
CH3O
N
1
the absorption bands ( , cm ) at 1660 v.s (C=N),
B
1525, 1500 v.s (triazine), 960 1000, and 1100 br.v.s
1
(POC). The N H absorption band at 3000 3400 cm
The reaction of 2,4-dimethoxy-6-chloro-1,3,5-tri-
azine VII with the potassium salt of N-diisopropoxy-
thiophosphorylthiobenzamide IIa occurs in refluxing
acetone and gives 2,4-dimethoxy-6-(S-isothiobenz-
amido-N-diisopropoxythiophosphoryl)-1,3,5-triazine
XIV in a relatively low yield (24%). Its IR and 31P
NMR spectra are consistent with the suggested struc-
ture (see table).
is absent. The signal at 54 ppm in the 31P NMR spec-
trum confirms the structure of amidothiophosphate
and, similarly to the above-mentioned cases, suggests
the occurrence of the reaction at the sulfur atom of
the C=S group.
Cl
N
N
1:1
Cl
Cl
Z
Z
CH3O
CH3O
N
XI
Z
N
N
+ IIa
N
N
+ IIa
OCH3
S
CH3O
N
VII
Cl
CH3O
N
VI
N
N
1:2
Ph
N
S C=N P(OC3H7-i)2
XII
N
N
Z = S C(Ph)=N P(S)(OPr-i)2.
OCH3
N
CH3O
We have found that the disubstituted product is
hydrolytically unstable. Elution with acetone from the
XIV
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 4 2003

REACTION OF POTASSIUM SALTS OF N-(THIO)PHOSPHORYLTHIOAMIDES
641
Under the action of atmospheric moisture, phos-
phorus-containing dimethoxytriazine XIV decomposes
to form N-diisopropoxythiophosphorylthiobenzamide
Ia and 2,4-dimethoxy-6-hydroxy-1,3,5-triazine XV
whose structure was confirmed by IR spectroscopy.
Thioamide Ia was isolated from the reaction mixture
and characterized spectroscopically; its structure was
confirmed by coincidence of its constants with the
published data [11].
4,6-bis(N-diisopropoxythiophosphorylthiobenzimido-
yl)-1,3,5-triazine IX, 5.57 g, was obtained as a dark
red liquid, n2D0 1.5770,
56 ppm. Yield 75% based
on IIa. Found, %: C 46.P02; H 5.04; P 8.29. C29H38
N5ClO4P2S4. Calculated, %: C 46.67; H 5.09; P 8.32.
Reaction of potassium salt of N-diisopropoxy-
thiophosphorylthiobenzamide IIa with 2-methoxy-
4,6-dichloro-1,3,5-triazine VI in 1:1 molar ratio.
A solution of 3.56 g of IIa in 100 ml of anhydrous
acetone was slowly added dropwise with vigorous
stirring to a solution of 1.80 g of 2-methoxy-4,6-di-
chloro-1,3,5-triazine in 50 ml of anhydrous acetone.
The reaction mixture was allowed to stand at room
temperature for 8 h, the KCl precipitate was filtered
off, and solvent was removed in a water-jet-pump
vacuum. The residue was dissolved in carbon tetra-
chloride and thrice chromatographed on 40 g of
neutral alumina (Brockmann grade II). Then the sol-
vent was removed, and 2.90 g (63%) of 2-methoxy-4-
chloro-6-(N-diisopropoxythiophosphorylthiobenz-
imidoyl)-1,3,5-triazine XI was obtained; n2D0 1.6373,
OH
[H2O]
N
N
XIV
+ Ia
OCH3
CH3O
N
XV
The lability of imidothiyl derivatives of 1,3,5-tri-
azine IX XIV, as compared to the previously studied
imidothiotates, may be due to the fact that the carbon
atom in 1,3,5-triazine is subjected to a strong electron-
accepting effect of the neighboring nitrogen atom, and
in its properties it resembles acyl rather than alkyl
carbon atom.
62 ppm. Found, %: C 44.11; H 4.69; P 6.54.
P
C17H22ClN4O3PS2. Calculated, %: C 44.29; H 4.70;
P 6.73.
We also attempted to perform the reaction of thio-
amides I and their salts with acyl halides, but these
reactions are nonselective and yield numerous prod-
ucts (up to 10 signals are observed in the 31P NMR
spectrum); we failed to isolate them pure and charac-
terize. Note that the 31P NMR spectrum contains
strong signals at 71 and 86 ppm, which were also
observed in the reaction of salts II with compounds
VI and VII.
Reaction of potassium salt of N-diisopropoxy-
thiophosphorylthiobenzamide IIa with 2,4-dimeth-
oxy-6-chloro-1,3,5-triazine VII. A solution of 3.56 g
of IIa in 50 ml of absolute dioxane was slowly added
dropwise with vigorous stirring to a solution of
1.76 g of 2,4-dimethoxy-6-chloro-1,3,5-triazine VII in
50 ml of absolute dioxane. The mixture was refluxed
for 0.5 h, the KCl precipitate was filtered off, and the
solvent was removed in a water-jet-pump vacuum.
The residue was dissolved in carbon tetrachloride and
thrice chromatographed on 40 g of neutral alumina
(Brockmann grade II). The solvent was removed, and
1.1 g (24%) of 2,4-dimethoxy-6-(N-diisopropoxythio-
phosphorylthiobenzimidoyl)-1,3,5-triazine XIV was
EXPERIMENTAL
The IR spectra were recorded on a Specord M-80
spectrometer for liquid films and mulls in mineral oil
1
in the range 400 3700 cm . The 31P NMR spectra
were measured on a KGU-4 custom-made NMR spec-
trometer (8 MHz) against external 85% phosphoric
acid.
obtained,
58 ppm.
P
Reaction of potassium salt of N-diisopropoxy-
thiophosphorylthiobenzamide IIa with 2-methoxy-
4,6-dichloro-1,3,5-triazine VI in 1:2 ratio. A solu-
tion of 11.1 g of IIa in 50 ml of absolute dioxane was
slowly added dropwise with vigorous stirring to a
solution of 1.80 g of 2-methoxy-4,6-dichloro-1,3,5-
triazine in 50 ml of absolute dioxane. The reaction
mixture was refluxed for 1 h, the KCl precipitate was
filtered off, the solvent was removed in a water-jet-
pump vacuum, and the residue was dissolved in
benzene and thrice chromatographed on 40 g of neutral
alumina (Brockmann grade II). Then the solvent was
removed, and 4.3 g (58%) of 2,4-(N-diisopropoxythio-
Reaction of potassium salt of N-diisopropoxy-
phosphorylthiobenzamide IIa with 2,4,6-trichloro-
1,3,5-triazine V in 1:1 ratio. A solution of 7.12 g of
potassium amide IIa in 30 ml of anhydrous acetone
was slowly added dropwise with vigorous stirring at
0 C to a solution of 3.69 g of cyanuric acid chloride
V in 50 ml of anhydrous acetone. The reaction mix-
ture was allowed to stand at room temperature for 8 h,
the KCl precipitate was filtered off, and the solvent
was removed in a water-jet-pump vacuum. The
residue was dissolved in hexane and thrice chro-
matographed on 50 g of neutral alumina (Brockmann
grade II), and then the solvent was removed. 2-Chloro- phosphorylthiobenzimidoyl)-6-methoxy-1,3,5-triazine
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 4 2003

642
ZABIROV et al.
XII was obtained as a viscous reddish brown oil,
54 ppm. Found, %: C 48.40; H 5.32; P 8.40. C30H41
N5O5S4P2. Calculated, %: C 48.53; H 5.53; P 8.36.
The alumina was repeatedly washed with acetone.
After removing the solvent, 0.4 g (10%) of 2-(N-di-
isopropoxythiophosphorylthiobenzimidoyl)-4-hydr-
oxy-6-methoxy-1,3,5-triazine XIII was obtained as a
2,4,6-Tris(S-isothiobenzamido-N-diisopropoxy-
phosphoryl)-1,3,5-triazine Xb. Yield 4.80 g (49%),
P
n2D0 1.6428,
3 ppm. Found, %: C 55.05; H 5.60;
P
P 9.39. C42H57N6O9P3S3. Calculated, %: C 55.20;
H 5.82; P 9.49.
ACKNOWLEDGMENTS
red oil,
54 ppm.
P
The study was financially supported by the Russian
Foundation for Basic Research (project no. 00-03-
32742) and the joint program of CRDF and the
Ministry of Education of the Russian Federation
Basic Research and Higher Education (grant
no. REC-007).
Reaction of potassium salts of N-(thio)phospho-
rylthiobenzamides IIa and IIb with cyanuric acid
chloride in 1:2 ratio (general procedure). A solution
of 0.02 mol of potassium salt of N-(thio)phosphoryl-
thiobenzamide IIa or IIb in 50 ml of anhydrous
acetone was slowly added dropwise with vigorous
stirring to a solution of 1.84 g of V in 30 ml of an-
hydrous acetone. The mixture was refluxed for 15 min
and allowed to stand at room temperature for 8 h. The
KCl precipitate was filtered off, and the solvent was
removed in a water-jet-pump vacuum. The residue
was extracted with hexane, and the solvent was
removed.
REFERENCES
1. Zabirov, N.G., Shamsevaleev, F.M., and Cherka-
sov, R.A., Zh. Obshch. Khim., 1990, vol. 60, no. 3,
p. 533.
2. Zabirov, N.G., Shamsevaleev, F.M., and Cherka-
sov, R.A., Zh. Obshch. Khim., 1992, vol. 62, no. 5,
p. 1071.
2,4-Bis(N-diisopropoxythiophosphorylthiobenz-
imidoyl)-6-chloro-1,3,5-triazine IXa. Yield 5.80 g
3. Zabirov, N.G., Cherkasov, R.A., and Pudovik, A.N.,
(78%), n2D0 1.5764,
56 ppm. Found, %: C 46.12; H
P
Zh. Obshch. Khim., 1986, vol. 56, no. 6, p. 1237.
5.04; P 8.29. C29H38ClN5O4P2S4. Calculated, %:
C 46.67; H 5.09; P 8.32.
4. Zabirov, N.G., Sokolov, F.D., and Cherkasov, R.A.,
Zh. Obshch. Khim., 1998, vol. 68, no. 6, p. 1100.
2,4-Bis(N-diisopropoxyphosphorylthiobenzimi-
doyl)-6-chloro-1,3,5-triazine IXb. Yield 4.36 g
5. Zabirov, N.G., Sokolov, F.D., and Cherkasov, R.A.,
Zh. Obshch. Khim., 1998, vol. 68, no. 9, p. 1582.
(61%), n2D5 1.6804,
8 ppm. Found, %: C 48.30; H
5.21; P 8.65. C29H3P8ClN5O6P2S2. Calculated, %: C
48.73; H 5.32; P 8.67.
6. Kulikova, O.A., Razvodovskaya, L.V., and Mel’ni-
kov, N.N., Zh. Obshch. Khim., 1982, vol. 52, no. 5,
p. 1108.
Reaction of potassium salts of N-(thio)phos-
phorylthiobenzamides IIa and IIb with cyanuric
acid chloride in 1:3 ratio (general procedure). A
solution of 0.03 mol of potassium salt of N-(thio)phos-
phorylthiobenzamide IIa or IIb in 70 ml of anhydrous
acetone was slowly added dropwise with vigorous
stirring to a solution of 1.84 g of cyanuric acid
chloride V in 30 ml of anhydrous acetone. The reac-
tion mixture was refluxed for 4 h, the KCl precipitate
was filtered off, and the solvent was removed in a
water-jet-pump vacuum. The residue was dissolved in
benzene and twice chromatographed on 40 g of
neutral alumina (Brockmann grade II). Then the
solvent was removed.
7. Kulikova, O.A., Razvodovskaya, L.V., and Mel’ni-
kov, N.N., Zh. Obshch. Khim., 1982, vol. 52, no. 5,
p. 1103.
8. Mel’nikov, N.N., Kulikova, O.A., Razvodov-
skaya, L.V., and Ponkratenko, G.A., USSR Inventor’s
Certificate no. 668283, 1980, Byull. Izobret., 1981,
no. 19.
9. Mel’nikov, N.N., Kulikova, O.A., Razvodov-
skaya, L.V., and Ponkratenko, G.A., USSR Inventor’s
Certificate no 629699, 1980, Byull. Izobret., 1981,
no. 19.
10. Mel’nikov, N.N., Kulikova, O.A., Razvodov-
skaya, L.V., and Ponkratenko, G.A., USSR Inventor’s
Certificate no. 688284, 1980, Ref. Zh. Khim., 1982,
no. 20O339.
2,4,6-Tris(N-diisopropoxythiophosphorylbenz-
imidoyl)-1,3,5-triazine Xa. Yield 5.54 g (57.4%), nD20
1.5970,
56 ppm. Found, %: C 49.21; H 5.59; P
11. Pudovik, A.N., Cherkasov, R.A., Zimin, M.G., and
Zabirov, N.G., Izv. Akad. Nauk SSSR, Ser. Khim.,
1979, no. 4, p. 861.
P
8.91. C42H57N6O6P3S6. Calculated, %: C 49.12; H
5.55; P 9.06.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 4 2003