Phosphoramides: Synthesis, spectroscopy, and x-ray crystallography

Article abstract of DOI:10.1002/hc.21107

A series of new phosphoramides with general formula RP(O)X₂, where R = amino/p-methylphenoxy and X = amine, were synthesized and characterized by ¹H, ¹³C, ³¹P nuclear magnetic resonance (NMR), and infrared (IR) spectroscopy and elemental analysis. The ³¹P{¹H} NMR spectra show that among compounds 7-9 containing 2-, 3-, and 4-aminopyridinyl moieties, respectively, the shielding order of the P atom decreases as 7 > 9 > 8. Also, the structure of compound 7 was determined by X-ray crystallography. In this structure, repeated noncentrosymmetric dimers are formed by two strong intermolecular N(1)-H(1N).N(2) and N(3)-H(3N).O(1) hydrogen bonds. Taking into account weak intermolecular C(17)-H(17C).N(4), C(17)-H(17E).N(4), C(2)-H(2A).O(2), and also weak aromatic C - H.C interactions, a three-dimensional polymeric chain is created in the crystalline network. The density functional theory calculations at B3LYP, B3PW91, and M06 levels using the 6-31+G * basis set were in good agreement with the X-ray crystallography data.

Full text of DOI:10.1002/hc.21107

Heteroatom Chemistry
Volume 00, Number 00, 2013
Phosphoramides: Synthesis, Spectroscopy,
and X-ray Crystallography
Khodayar Gholivand,1 Zahra Shariatinia,2 and Nasrin Oroujzadeh3
1Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran
2Department of Chemistry, Amirkabir University of Technology (Polytechnic), P.O. Box
15875-4413, Tehran, Iran
3Department of Chemical Industries, Iranian Research Organization for Science and Technology
(IROST), P.O. Box: 33535-111, Tehran, Iran
Received 18 March 2013; revised 21 June 2013
this article online at wileyonlinelibrary.com. DOI
ABSTRACT: A series of new phosphoramides with
10.1002/hc.21107
general formula RP(O)X2, where R = amino/p-
methylphenoxy and X = amine, were synthesized and
characterized by 1H, 13C, 31P nuclear magnetic res-
onance (NMR), and infrared (IR) spectroscopy and
elemental analysis. The 31P{1H}NMR spectra show
that among compounds 7–9 containing 2-, 3-, and
4-aminopyridinyl moieties, respectively, the shield-
ing order of the P atom decreases as 7 > 9 > 8.
Also, the structure of compound 7 was deter-
mined by X-ray crystallography. In this structure, re-
peated noncentrosymmetric dimers are formed by two
strong intermolecular N(1)-H(1N) . . . N(2) and N(3)-
H(3N) . . . O(1) hydrogen bonds. Taking into account
weak intermolecular C(17)-H(17C) . . . N(4), C(17)-
H(17E) . . . N(4), C(2)-H(2A) . . . O(2), and also weak
aromatic C H . . . C interactions, a three-dimensional
polymeric chain is created in the crystalline net-
work. The density functional theory calculations
at B3LYP, B3PW91, and M06 levels using the 6–
31+G** basis set were in good agreement with the
INTRODUCTION
In recent years, the chemistry of phosphoramides
has become very attractive owing to their various
important applications such as anticancer prodrug
compounds [1–4]. They have been utilized as potent
catalysts in aldol reactions [5,6] and in chiral asym-
metric synthesis [7–10]. The highly enantioselec-
tive vinylogous addition of 2-trimethylsilyloxyfuran
to aldehydes was performed using chiral phos-
phoramides as Lewis bases [11]. These types of
compounds are also effective inhibitors for ureas
[12, 13], acetylcholinesterase [14–16], and butyryl-
cholinesterase [17] enzymes. The biocidal activity
of phosphoramides are well known so that they are
applied as pesticides and insecticides in agriculture
[18, 19]. The presence of phosphoryl or carbonyl
oxygen donor sites enables them to be appropriate
ligands in coordination chemistry [20–23]. So far,
the synthesis, spectroscopic, and structural investi-
gations on a number of such compounds have been
performed [24–28].
ꢀC
X-ray crystallography data.
2013 Wiley Period-
icals, Inc. Heteroatom Chem 00:1–9, 2013; View
Correspondence to: K. Gholivand; e-mail: gholi_kh@modares.
In this work, 10 new phosphoramides were syn-
thesized and characterized by multinuclear (1H, 13C,
and 31P) nuclear magnetic resonance NMR, infrared
IR spectroscopy, and elemental analysis. Also, the
molecular structure of compound 7 was determined
ac.ir.
Contract grant sponsor: Research Council of Tarbiat Modares
University.
Contract
grant
sponsor:
Amirkabir
University
of
Technology.
ꢀC
2013 Wiley Periodicals, Inc.
1

2
Gholivand, Shariatinia, and Oroujzadeh
SCHEME 1 The preparation pathway of compounds 1–10.
by X-ray crystallography. The effects of various sub-
stituents on the spectroscopic results were inter-
preted and discussed.
the range of –9.20 ppm (in 4) to 8.94 ppm (in 6)
displaying various electron-donation powers of the
substituents to the phosphorus atoms. A compari-
son indicates that the δ(31P) values of analogues 7
and 10 as well as those of 8 and 9 are close to each
other. Moreover, among compounds 7–9 containing
2-, 3- and 4-aminopyridinyl moieties, respectively,
the molecule 7 has the most shielded phosphorus
atom and the shielding order of the P atom decreases
as 7 > 9 > 8. Similarly, the phosphorus atom in 2
(containing three 3-aminopyridinyl groups) is more
shielded than in 1 (bearing three anilinyl rings). The
structures of 4 and 8 are similar to that of 2 in which
one of the 3-aminopyridinyl groups is replaced with
cyclohexylamine and p-cresol moieties, respectively.
It is seen that the phosphorus atom is the most
RESULTS AND DISCUSSION
Spectroscopic Study
In this study, new phosphoramides 1–10 were syn-
thesized from the reaction of POCl3/RPOCl2 with
different amines (Scheme 1) and fully characterized
by NMR and IR spectroscopy. A summary of the
spectroscopic data of these compounds are given in
Table 1. The comparative analysis of the spectra re-
veals interesting features. The 31P{1H}NMR spectra
indicate the phosphorus chemical shift, δ(31P), in
Heteroatom Chemistry DOI 10.1002/hc

Phosphoramides: Synthesis, Spectroscopy, and X-ray Crystallography
3
TABLE 1 Selected Spectroscopic NMR and IR Data of Compounds 1–10
δ(31P)
Compound (ppm)
ν(P O)
ν(P N)
2J(PNH) (Hz)
2J(P,C) (Hz)
3J(P,C) (Hz)
(cm−1
)
(cm−1
)
1
–3.42 10.0
—
7.9
7.4
6.1
1214
1186
1196
1180
1183
1176
1217
1212
1212
1219
928
955
987, 949
1057, 929
1103, 907
1104, 913
897
2
–4.16
2.47
–9.20
9.7
3
7.7 (benzylamine)
7.2 (aminopyridine)
—
4.5 (aminopyridine)
4
7.2 (aminopyridine) 5.7 (aminopyridine)
5
5.97 10.6 (cyclohexylamine)
8.94 11.1 (furfuryl), 8.5 (nitroaniline)
10.4 (nitroaniline)
—
7.7 (cresol)
8.9 (aminopyridine) 7.0 (amine), 4.5 (cresol)
—
6.9 (nitroaniline)
7.0, 7.2
9.0 (amine), 4.1 (cresol)
6
7
–8.53
–2.10
–3.9
—
9.5
—
—
8
947
942
908
9
6.8 (amine), 4.5 (cresol)
6.0 (amine), 4.0 (cresol)
10
–7.42
6.9 (cresol)
shielded atom in 4 (δ(31P) = –9.20 ppm) whereas in
8, it is the most deshielded one (δ(31P) = –2.10 ppm).
Thus, the overall electron donation of substituents
to the phosphorus atom is the highest one with the
cyclohexylamine group.
The analysis of the IR spectra indicate that
the fundamental ν(P O) stretching modes for com-
pounds 1–10 appear in the range of 1176 cm−1 (in
6) and 1219 cm−1 (in 10), while the ν(P N) of 6
(1104 cm−1) shows the greatest value among those
of 1–10. Comparison of the ν(P O) and ν(P–N) of
the very analogous compounds 1 and 2 indicates
stronger P O but weaker P–N bonds in 1. Interest-
ingly, it can be seen that similar to the δ(31P) values,
the ν(P O) and ν(P–N) of compounds 7 and 10 as
well as those of compounds 8 and 9 are very close to
each other. Moreover, among compounds 7–9 con-
taining 2-, 3-, and 4-aminopyridinyl moieties, respec-
tively, the molecule 7 shows the strongest P O bond,
while those of 8 and 9 are identical. A comparison of
the ν(P O) for similar molecules 2, 4, and 8 reveals
that the P O bond stretching frequencies change as
8 > 2 > 4.
The 1H NMR spectra show geminal 2J(PNH) cou-
pling constants in the range of 11.1 Hz (in 6) to
2
7.2 Hz (in 4). The greatest J(PNH) values are ob-
served for compounds 5 and 6 for the coupling of
NH protons of cyclohexylamine and furfuryl groups
with the phosphorus atoms. As both molecules 5
and 6 include 4-nitroaniline group, it can be con-
cluded that this electron-withdrawing moiety can
cause more interaction between the phosphorus
atoms and amino protons of cyclohexylamine and
2
furfuryl groups. The comparison of the J(PNH) in-
dicates that the substitution of aniline rings in 1
by 3-aminopyridine groups in 2 can cause its de-
crease from 10.0 to 9.7 Hz. Similarly, substitution
of one of 3-aminopyridine moiety in 2 by cyclohexy-
lamine in 4 results in a decrease in 2J(PNH) from 9.7
X-Ray Crystallography
2
to 7.2 Hz. But, the J(PNH) value does not change
Herein, to more investigate the structural proper-
ties of phosphoramides, the structure of compound
7 has been determined by X-ray crystallography. Sin-
gle crystals of the compound were obtained from
a solution of CH3CN/n-hexane at room tempera-
ture. The crystallographic data and the details of the
X-ray analysis are presented in Table 2, while se-
lected bond lengths and angles are given in Table 3.
Hydrogen bonding data of these structures are given
in Table 4. The ORTEP view [29] and the three-
dimensional polymeric chain generated by hydrogen
bonds [30] are shown in Figs. 1 and 2.
very much by the replacement of 3-aminopyridine
group in 2 with p-cresol in 8 (2J(PNH) = 9.5 Hz).
1
The H NMR spectrum of molecule 3 exhibits that
3
the vicinal J(PNCH) = 10.3 Hz for the coupling of
benzylic CH2 protons with the phosphorus atom.
Such coupling constants were also observed for
previously reported phosphoramides [24–27]. The
1H and 13C NMR spectra of 10 reveal two sets
of signals for the aromatic protons of the two 2-
aminopyridinyl rings. This may be attributed to the
different spatial orientation of the rings to each
other, leading to a prochiral phosphorus atom. The
13C NMR spectra exhibit 2,3J(P,Caromatic) coupling
constants so that in compounds 2, 4, 5, 7, 8, and 10,
2J(P,Caromatic) > 3J(P,Caromatic). Furthermore, com-
paring the 2,3J(P,Caromatic) for analogues 2, 4, and
8 shows that the coupling constants values vary in
the order 8 > 2 > 4.
In this structure, the C(10), H(10), and N(4)
atoms indicate disorder. Such behavior have been
observed with several crystal structures [31,32]. The
˚
P O bond length in the molecule is 1.4696(12) A,
which is slightly longer than the normal P O bond
˚
length (1.45 A) [33]. The P O bond length (between
phosphorus and oxygen atom of p-cresol group)
Heteroatom Chemistry DOI 10.1002/hc

4
Gholivand, Shariatinia, and Oroujzadeh
◦
˚
TABLE 2 Crystallographic Data for Compound 7
TABLE 3 Selected Bond Lengths (A) and Angles ( ) for
Compound 7
Chemical formula
C17H17N4O2P1
P(1) O(1)
P(1) O(2)
P(1) N(3)
P(1) N(1)
1.4696(12) O(1) P(1) O(2)
1.5898(12) O(1) P(1) N(3)
1.6440(14) O(2) P(1) N(3)
1.6483(14) O(1) P(1) N(1)
114.92(7)
109.23(7)
108.82(7)
116.57(7)
97.15(6)
Formula weight
Crystal system, space
group
340.32
Triclinic, P –1
Temperature (K)
120(2)
9.6241(8), 9.8398(8),
10.6887(9)
73.075(2), 70.372(2), 63.275(2)
839.67(12)
2
1.346
O(2) C(11) 1.4130(18) O(2) P(1) N(1)
N(1) C(1) 1.394(2) N(3) P(1) N(1)
N(1) H(1N) 0.8313
N(2) C(1)
N(2) C(2)
N(3) C(6)
˚
a, b, c (A)
109.49(7)
C(11) O(2) P(1) 120.25(10)
C(1) N(1) P(1) 123.50(11)
C(1) N(1) H(1N) 116.9
α, β, γ (◦)
Volume (A )
1.342(2)
1.345(2)
3
˚
Z
1.4011(19) P(1) N(1) H(1N) 115.0
Density (calculated,
mg/m3)
N(3) H(3N) 0.8895
C(1) N(2) C(2)
1.3408(10) C(6) N(3) P(1)
1.433(7)
117.57(14)
127.02(10)
N(4) C(6)
N(4) C(7)
Absorption coefficient
0.181
C(6) N(3) H(3N) 114.1
(mm−1
)
N(4ꢁ) C(6) 1.3426(10) P(1) N(3) H(3N) 117.7
Crystal size (mm3)
Theta range for data
collection (◦)
0.30 × 0.14 × 0.13
N(4ꢁ) C(9) 1.504(4)
C(1) C(5) 1.408(2)
C(6) N(4) C(7)
C(6) N(4’) C(9) 111.2(3)
114.0(4)
2.05 to 28.99
Index ranges
–13 <= h <= 13, –13 <=
k <= 13, –14 <= l <= 14
9327
TABLE 4 The Hydrogen Bonding Data of Compound 7
◦
˚
(A, )
Reflections collected
Independent reflections
Completeness to
theta = 28.99◦
4434 [R(int) = 0.0198]
D—H···A
D—H H···A
D···A ∠D—H···A
99.5%
N(1) H(1N) . . . N(2)a 0.8300 2.1500 2.971(2) 168.00
N(3) H(3N) . . . O(1)b 0.8900 2.0000 2.860(2) 161.00
Absorption correction
Maximum and minimum
transmission
Semiempirical from equivalents
0.977 and 0.940
Symmetry transformations used to generate equivalent atoms.
a–x+1,–y+1,–z.
Refinement method
Data/restraints/
Full matrix least squares on F2
4434/4/218
bx+1,–y+1,–z+1.
parameters
Goodness-of-fit on F2
Final R indices for 3613
reflections with [I >
2sigma(I)]
0.945
C(17))-H(17E) . . . N(4), C(2))-H(2A) . . . O(2), and
also weak aromatic C H . . . C interactions, a three-
dimensional polymeric chain is produced in the crys-
talline network (Fig. 2).
R1 = 0.0482, wR2 = 0.1109
R indices (all data)
Largest differential peak
and hole
R1 = 0.0599, wR2 = 0.1200
−3
˚
0.450 and –0.356 e.A
Density Functional Theory (DFT) Calculations
To further investigate the structural properties of
compound 7, its geometry was calculated using
Gaussian 09 software [34] at B3LYP, B3PW91,
and M06 methods with 6–31+G** standard basis
set. The optimized structure has been shown in
˚
is 1.5898(12) A), which is smaller than the stan-
˚
dard P O single bond length (1.64 A) [33]. The
P atom has a slightly distorted tetrahedral config-
uration, that is, the surrounding angles around the
P atom are in the range of 97.15(6)◦–116.57(7)◦.
The two P N bonds (1.6440(14) and 1.6483(14)
A) are shorter than the typical P N single bond
length (1.77 A) [33], revealing the partial multi-
ple bond character in them. In this compound,
the angles P(1) N(1) C(1), P(1) N(1) H(1N) and
C(1) N(1) H(1N) are 123.50(11)◦, 115.0◦, and
116.9◦, respectively, with an average of 118.47◦. The
sum of surrounding angles around N(3) atom is
358.82◦.
Fig. 3 [35]. The stabilization energies (kcal mole−1
)
were calculated from the equation ꢀEstabilization
=
ꢀ
˚
E(molecule) −
E(i), i = atom or ion, Table 5.
i
˚
It is seen that the molecule indicates the most
ꢀEstabilization = –4619.784 kcal/mol at B3PW91/6–
31+G** level. This indicates that among three
computational levels, B3PW91 provides the lowest
molecular energy, thus the geometrical parameters
are calculated at this level to compare them with the
experimental ones.
In this structure, each molecule is connected
to another one by two strong intermolecular N(1)-
H(1N) . . . N(2) and N(3))-H(3N) . . . O(1) hydrogen
bonds, so that consecutive noncentrosymmetric
dimers are formed by these H bonds. Consid-
ering weak intermolecular C(17))-H(17C) . . . N(4),
The selected bond lengths and angles cal-
culated at B3PW91/6–31+G** level are given in
Table 6 revealing a good agreement with the X-ray
crystallography results. The two NH groups reveal
pseudo-trans conformation relative to each other
with N H . . . N H pseudo-torsion angle equal to
Heteroatom Chemistry DOI 10.1002/hc

Phosphoramides: Synthesis, Spectroscopy, and X-ray Crystallography
5
FIGURE 1 The ORTEP view of the crystal structure of compound 7.
FIGURE 2 The three-dimensional polymeric chain formed by hydrogen bonds and aromatic interactions in 7.
–24.89◦. The phosphorus atom adopts a distorted
tetrahedral configuration with the surrounding an-
gles in the range of 95.48◦ to 118.39◦.
In summary, the synthesis, spectroscopic, and
structural characterization of a series of ten new
phosphoramides has been performed. The struc-
ture of compound 4-CH3-C6H4-OP(O)(2-NC5H4-
NH)2 (7) showed a three-dimensional polymeric
chain in the crystalline lattice by intermolecular
strong N H . . . N, N H . . . O and weak C H . . . N,
C H . . . O hydrogen bonds plus aromatic C H . . . C
interactions. The 1H and 13C NMR spectra of
4-CH3-C6H4-OP(O)(p-NO2–2-NC5H3-NH)2 (10) re-
veal two sets of signals for the aromatic protons
of the two 2-aminopyridinyl rings that are probably
due to the different spatial orientation of the rings to
each other, leading to a prochiral phosphorus atom.
The DFT calculations (with B3LYP, B3PW91, and
M06 methods) using 6–31+G** basis set were in
agreement with the X-ray crystallography results.
Heteroatom Chemistry DOI 10.1002/hc

6
Gholivand, Shariatinia, and Oroujzadeh
FIGURE 3 The optimized structure of compound 7 at DFT methods with 6–31+G** basis set.
TABLE 5 Stabilization Energies (kcal/mol) for Compound 7
formed using the SADABS program [38] (Moscow,
Russia).
Method
ꢀE
B3LYP/6–31+G**
B3PW91//6–31+G**
M06//6–31+G**
–4570.490
–4619.784
–4606.297
Spectroscopic Measurements
1H, 13C, and 31P NMR spectra were recorded on a
Bruker Avance DRS 500 spectrometer. H and 13C
1
◦
˚
TABLE 6 Selected Bond Lengths (A) and Angles ( ) Calcu-
lated at B3PW91/6–31+G** Level for Compound 7
chemical shifts were determined relative to the inter-
nal tetramethylsilane (TMS), and 31P chemical shifts
were determined relative to 85% H3PO4 as the exter-
nal standard. IR spectra were recorded on a Shi-
madzu model IR-60 spectrometer. Elemental analy-
sis was performed using a Heraeus CHN-O-RAPID
apparatus. Melting points (mp) were obtained with
an electrothermal instrument.
P(1) O(1)
P(1) O(2)
P(1) N(3)
P(1) N(1)
O(2) C(11)
N(1) C(1)
N(1) H(1N)
N(2) C(1)
N(2) C(2)
N(3) C(6)
N(3) H(3N)
N(4) C(6)
N(4) C(7)
1.4753
1.6169
1.6721
1.6692
1.3944
1.3961
1.0146
1.3321
1.3355
1.3945
1.0157
1.3339
1.3333
O(1) P(1) O(2)
O(1) P(1) N(3)
O(2) P(1) N(3)
O(1) P(1) N(1)
O(2) P(1) N(1)
N(3) P(1) N(1)
C(11) O(2) P(1)
C(1) N(1) P(1)
C(1) N(1) H(1N)
P(1) N(1) H(1N)
C(1) N(2) C(2)
C(6) N(3) P(1)
C(6) N(3) H(3N)
117.87
108.41
107.36
118.39
95.48
108.28
119.64
126.01
113.76
118.15
117.57
132.20
113.02
Synthesis
General Procedure. For the synthesis of com-
pounds 1 and 2, to a solution of 10 mmol phos-
phorylchloride in dry acetonitrile, 60 mmol of cor-
responding amine was dropwise added at 0◦C and
the mixture was stirred for 10 h. Then the solution
was evaporated and the residue was washed with dis-
tilled water and dried. Compounds 3–10 were pre-
pared in a same manner, but 40 mmol of the re-
lated amine was added to 10 mmol of corresponding
R-substituted phosphoramidic dichloride (RP(O)Cl2
where R = amine or p-cresol).
N,Nꢁ,Nꢁꢁ-Tris(anilinyl) Phosphoric Triamide (1).
Yield: 87%; mp = 214.9◦C. Elemental analysis Calcd:
C, 66.87; H, 5.57; N, 13.00. Found: C, 66.85; H,
5.59; N, 12.99. IR (KBr, cm−1): 3345 (m, NH), 3025
(w), 1589 (s), 1483 (s), 1379 (s), 1280 (s), 1214
EXPERIMENTAL
X-ray Measurements
X-ray data of compound 7 was collected on a Bruker
SMART 1000 CCD area detector [36] (Moscow,
Russia) with graphite monochromated Mo Kα ra-
˚
diation (λ = 0.71073 A). The structures were refined
with SHELXL-97 [37] by full matrix least squares
on F2 (Moscow, Russia). The positions of hydrogen
atoms were obtained from the difference Fourier
map. Routine Lorentz and polarization corrections
were applied and an absorption correction was per-
Heteroatom Chemistry DOI 10.1002/hc

Phosphoramides: Synthesis, Spectroscopy, and X-ray Crystallography
7
(s, P O), 1177 (w), 1154 (w), 1024 (m), 994 (w),
928 (s, P N), 890 (w), 784 (w), 744 (s), 690 (s),
618 (m), 505 (m), 480 (m). H NMR (500.13 MHz,
1293 (m), 1238 (w), 1180 (s, P O), 1125 (w), 1105
(w), 1057 (s, P N), 929 (s, P N), 825 (w), 794 (m),
1
1
702 (m), 616 (m), 550 (m). H NMR (500.13 MHz,
D6-dimethylsulfoxide (DMSO), 25◦C, TMS): 6.79 (t,
3J(H,H) = 7.0 Hz, 3H, Ar H), 7.15 (m, 12H, Ar H),
7.90 (d, 2J(PNH) = 10.0 Hz, 3H, NH). 13C NMR
(125.76 MHz, D6-DMSO, 25◦C, TMS): 117.42 (d,
3J(P,C) = 7.4 Hz), 119.91 (s), 128.58 (s), 142.08 (s).
31P NMR (202.46 MHz, D6-DMSO, 25◦C, H3PO4 ex-
ternal): –3.42 (q, 2J(PNH) = 10.0 Hz).
D6-DMSO, 25◦C, TMS): 0.96–1.9 (m, 10H, CH2), 2.78
(m, 1H, CH), 4.28 (m, 1H, NHcyclohexylamine), 6.97 (t,
3J(H,H) = 7.8 Hz, 2H, Ar H), 7.18 (d, 2J(PNH) = 7.2
Hz, 2H, NH), 7.43 (d, 3J(H,H) = 7.8 Hz, 2H, Ar H),
3
7.75 (d, J(H,H) = 7.8 Hz, 2H), 8.28 (s, 2H, Ar H).
13C NMR (125.76 MHz, D6-DMSO, 25◦C, TMS):
23.84 (s), 24.47 (s), 30.26 (s), 40.16 (s), 122.02 (d,
3J(P,C) = 5.7 Hz), 122.92 (s), 138.04 (s), 138.50
(d, 2J(P,C) = 7.2 Hz, Cipso), 141.29 (s). 31P NMR
(202.46 MHz, D6-DMSO, 25◦C, H3PO4 external):
–9.20 (m).
N,Nꢁ,Nꢁꢁ-Tris(3-aminopyridinyl) Phosphoric Tri-
amide (2). Yield: 85%; mp = 243.2◦C. Elemental
analysis (%) Calcd: C, 57.32; H, 4.78; N, 26.75.
Found: C, 57.30; H, 4.78; N, 26.76. IR (KBr, cm−1):
3430 (s, NH), 3110 (s, CH), 2915 (m), 2755 (w),
1576 (s), 1494 (m), 1463 (s), 1399 (m), 1341 (w),
1262 (s), 1186 (s, P O), 1124 (w), 1045 (m), 955
(s, P N), 797 (m), 698 (m), 631 (w), 610 (m), 587
(w), 508 (w), 483 (w). 1H NMR (500.13 MHz, D6-
N-4-Nitrophenyl-Nꢁ,Nꢁꢁ-bis(cyclohexyl) Phospho-
ric Triamide (5). Yield: 89%; mp = 235.7◦C. El-
emental analysis (%) Calcd: C, 56.84; H, 7.63; N,
14.74. Found: C, 56.82; H, 7.65; N, 14.72. IR (KBr,
cm−1): ν = 3380 (s, NH), 3235 (m, NH), 2905 (s),
1583 (s, NO2), 1494 (s), 1442 (m), 1417 (w), 1321
(s, NO2), 1299 (s), 1255 (w), 1183 (s, P O), 1103 (s,
3
DMSO, 25◦C, TMS): 7.22 (t, J(H,H) = 7.6 Hz, 3H,
3
Ar H), 7.58 (d, J(H,H) = 7.6 Hz, 3H, Ar H), 8.07
(d, 3J(H,H) = 7.6 Hz, 3H, Ar H), 8.44 (s, 3H, Ar H),
8.47 (d, 2J(PNH) = 9.7 Hz, 3H, NH). 13C NMR
(125.76 MHz, D6-DMSO, 25◦C, TMS): 123.63 (s),
P
N), 1047 (w), 1008 (w), 907 (s, P N), 840 (w),
745 (w), 655 (w), 612 (w), 557 (w). 1H NMR (500.13
MHz, D6-DMSO, 25◦C, TMS): δ = 0.99–1.22 (m, 10H,
CH2), 1.45–1.86 (m, 10H, CH2), 2.85 (s, 2H, CH),
4.37 (d, 2J(PNH) = 10.6 Hz, 2H, NHcyclohexylamine),
3
124.18 (d, J(P,C) = 6.1 Hz), 138.35 (s), 139.55 (d,
2J(P,C) = 7.9 Hz, Cipso), 141.64 (s). 31P NMR (202.46
MHz, D6-DMSO, 25◦C, H3PO4 external): –4.16 (q,
2J(PNH) = 9.7 Hz).
3
7.26 (d, J(H,H) = 9.2 Hz, 2H, Ar H), 8.00 (m, 3H,
2Ar H+ 1NH). 13C NMR (125.76 MHz, D6-DMSO,
25◦C, TMS): δ = 23.84 (s), 24.91 (s), 35.17 (s), 35.32
N-2-Aminopyridinyl-Nꢁ,Nꢁꢁ-dibenzyl Phosphoric
Triamide (3). Yield: 86%; mp = 294.2◦C. Ele-
mental analysis (%) Calcd: C, 64.77; H, 5.97; N,
15.91. Found: C, 64.76; H, 5.99; N, 15.92. IR (KBr,
cm−1):ν = 3105 (s), 2915 (s), 1592 (s), 1460 (s),
1385 (m), 1301 (m), 1268 (w), 1237 (m), 1196 (s,
P O), 1145 (m), 1104 (s), 1065 (m), 987 (s, P N),
949 (s, P N), 890 (m), 866 (m), 821(w), 767 (m),
3
(s), 49.55 (s), 116.40 (d, J(P,C) = 6.9 Hz), 124.89
(d, 2J(P,C) = 10.4 Hz), 138.86 (s), 150.85 (s). 31P
NMR (202.46 MHz, D6-DMSO, 25◦C, H3PO4 exter-
nal): δ = 5.97 (m).
N-4-nitrophenyl-Nꢁ,Nꢁꢁ-bis(furfuryl) Phosphoric
Triamide (6). Yield: 83%; mp = 135.7◦C. Elemental
analysis (%) Calcd: C, 51.06; H, 4.52; N, 14.89.
Found: C, 51.04; H, 4.53; N, 14.90. IR (KBr, cm−1):
3360 (m, NH), 3195 (s), 2895 (w),1590 (s, NO2),
1494 (s), 1456 (m), 1335 (s, NO2), 1298 (s), 1250
(m), 1176 (s, P O), 1144 (m), 1104 (m, P N), 1083
(w), 913 (s, P N), 839 (m), 800 (w), 731 (m), 653
(w). 1H NMR (500.13 MHz, D6-DMSO, 25◦C, TMS):
3.96 (m, 4H, CH2), 5.15 (d, 2J(PNH) = 11.1 Hz,
3J(H,H) = 6.8 Hz, 2H, NH), 6.19 (s, 2H, Ar H),
1
743 (m), 691 (m), 497 (s). H NMR (500.13 MHz,
3
D6-DMSO, 25◦C, TMS): δ = 4.06 (dd, J(H,H) = 7.5
Hz, 3J(PNCH) = 10.3 Hz, 4H, CH2), 5.28 (d,
2J(PNH) = 7.7 Hz, 2H, NH), 6.78–7.55 (m, 14H,
Ar H), 8.09 (b, 1H, NH). 13C NMR (125.76 MHz,
D6-DMSO, 25◦C, TMS): δ = 43.75 (s, CH2), 111.15
3
(d, J(P,C) = 4.5 Hz), 115.81 (s), 126.41 (s), 127.12
(s), 127.33 (s), 127.89 (s), 128.09 (s), 128.26 (s),
137.47 (s), 147.54 (s), 154.78 (s). 31P NMR (202.46
MHz, D6-DMSO, 25◦C, H3PO4 external): δ = 2.47
(m).
3
6.31 (s, 2H, Ar H), 7.25 (d, J(H,H) = 9.2 Hz, 2H,
3
Ar H), 7.48 (d, J(H,H) = 9.2 Hz, 2H, Ar H), 8.02
(d, 3J(H,H) = 9.2 Hz, 2H), 8.10 (d, 2J(PNH) = 8.5 Hz,
1H, NH). 13C NMR (125.76 MHz, D6-DMSO, 25◦C,
TMS): 37.23 (s, CH2), 106.20 (s), 110.22 (s), 116.63
(d, 3J(P,C) = 7.0 Hz, nitroaniline), 124.79 (s), 139.29
N-Cyclohexyl-Nꢁ,Nꢁꢁ-bis(3-aminopyridinyl) Phos-
phoric Triamide (4). Yield: 85%; mp = 204.9◦C. Ele-
mental analysis (%) Calcd: C, 58.01; H, 6.65; N, 21.15.
Found: C, 58.03; H, 6.64; N, 21.17. IR (KBr, cm−1):
ν = 3425 (m, NH), 3160 (s, NH), 3035 (m), 2865 (s),
1578 (s, νring), 1499 (s), 1475 (s), 1393 (m), 1333 (w),
3
(s), 141.59 (s), 150.27 (s), 154.01 (d, J(P,C) = 7.2
Hz, furfuryl). 31P NMR (202.46 MHz, D6-DMSO,
25◦C, H3PO4 external): 8.94 (m).
Heteroatom Chemistry DOI 10.1002/hc

8
Gholivand, Shariatinia, and Oroujzadeh
N,Nꢁ-Bis(2-aminopyridinyl)
Phosphoramidic
δ = 20.20 (s, CH3), 112.18 (d, 3J(P,C)amine = 6.8 Hz),
3
Acid (4-methylphenyl) Ester (7). Yield: 84%;
mp = 165.5◦C. Elemental analysis (%) Calcd: C,
60.00; H, 5.00; N, 16.47. Found: C, 60.01; H, 5.1; N,
16.46. IR (KBr, cm−1): ν = 3405 (w, NH), 3090 (m),
3000 (m), 2920 (m), 1636 (s), 1603 (s), 1543(s), 1496
(m), 1417 (m), 1379 (w), 1276 (m), 1245 (s), 1217 (s,
P O), 1158 (w), 1071 (s, P N), 1098 (w), 1024 (w),
995 (w), 937 (w), 897 (s, P N), 822 (m), 798 (m),
762 (m), 720 (w), 675 (m), 618 (m), 533 (m), 520 (m),
490 (m), 468 (w). 1H NMR (500.13 MHz, D6-DMSO,
25◦C, TMS): δ = 2.19 (s, 3H, CH3), 6.93–7.05 (m, 8H,
120.03 (d, J(P,C)cresol = 4.5 Hz), 130.17 (s), 134.34
(s), 147.47 (s), 147.69 (s), 150.04 (s). 31P NMR
(202.46 MHz, D6-DMSO, 25◦C, H3PO4 external):
δ = –3.9 (s).
N,Nꢁ-Bis(2-amino-5-nitro Pyridinyl) Phospho-
ramidic Acid (4-methylphenyl) Ester (10). Yield:
96%; mp = 164.8◦C. Elemental analysis (%) Calcd:
C, 47.44; H, 3.49; N, 19.53. Found: C, 47.42; H, 3.50;
N, 19.51. IR (KBr, cm−1): ν = 3370 (w, NH), 3225
(m, NH), 3100 (m, CH), 3000 (m), 2745 (w), 1668 (s),
1587 (m, NO2), 1494 (s), 1346 (s, NO2), 1283 (m),
1238 (w), 1219 (s, P O), 1157 (w), 1113 (w), 1072
(s, P N), 990 (w), 908 (m, P N), 830 (m), 759 (w),
718 (w), 631 (m), 545 (m), 488 (m). 1H NMR (500.13
3
Ar H), 7.97 (m, 2H, Ar H), 8.12 (d, J(H,H) = 8.1
Hz, 2H, Ar H), 9.51 (s, 2H, NH). 13C NMR (125.76
MHz, D6-DMSO, 25◦C, TMS): δ = 20.11 (s, CH3),
3
113.91 (s), 114.54 (d, J(P,C)amine = 9.0 Hz), 120.32
(d, 3J(P,C)cresol = 4.1 Hz), 129.36 (s), 131.93 (s),
MHz, D6-DMSO, 25◦C, TMS): δ = 2.20 (s, 3H, CH3),
2
3
136.68 (s), 144.28 (s), 150.19 (d, J(P,C)cresol = 7.7
6.53 (d, J(H,H) = 8.9 Hz, 1H), 7.04 (m, 4H, Ar
H
Hz), 152.72 (s). 31P NMR (202.46 MHz, D6-DMSO,
3
of cresol), 7.13 (d, J(H,H) = 8.9 Hz, 1H), 8.12 (d,
25◦C, H3PO4 external): δ = –8.53 (s).
3J(H,H) = 8.1 Hz, 1H), 8.38 (d, J(H,H) = 8.1 Hz,
3
1H), 8.83 (s, 1H), 9.02 (s, 1H), 9.55 (s, 2H, NH). 13C
NMR (125.76 MHz, D6-DMSO, 25◦C, TMS): δ = 20.22
(s, CH3), 107.76 (s), 110.74 (d, 3J(P,C)amine = 6.0
Hz), 120.11 (d, 3J(P,C)cresol = 4.0 Hz), 129.75 (s),
132.95 (s), 133.38 (s), 133.61 (s), 134.43 (s), 137.91
(s), 144.86 (s), 146.17 (s), 148.81 (d, 2J(P,C)cresol = 6.9
Hz), 159.11 (s), 162.64 (s). 31P NMR (202.46 MHz,
D6-DMSO, 25◦C, H3PO4 external): δ = –7.42 (s).
N,Nꢁ-Bis(3-aminopyridinyl)
Phosphoramidic
Acid (4-methylphenyl) Ester (8). Yield: 89%;
mp = 217.2◦C. Elemental analysis (%) Calcd: C,
60.00; H, 5.00; N, 16.47. Found: C, 60.02; H, 4.99; N,
16.48. IR (KBr, cm−1): ν = 3405 (m, NH), 3130 (m),
2940 (m), 1579 (m, νring), 1494 (s), 1467 (s), 1396
(m), 1330 (w), 1272 (m), 1212 (s, P O), 1165 (m),
1127 (w), 1098 (w), 1016 (w), 979 (m, P N), 947 (s,
P
N), 808 (m), 748 (w), 698 (m), 609 (w), 557 (m),
492 (m). 1H NMR (500.13 MHz, D6-DMSO, 25◦C,
SUPPLEMENTARY INFORMATION
3
TMS): δ = 2.24 (s, 3H, CH3), 7.08 (d, J(H,H) = 8.0
Crystallographic data for the structure 7 have been
deposited with Cambridge Crystallographic Data
Center as supplementary publication no. CCDC
727893 (C17H17N4O2P1). Copies of the data may be
obtained, free of charge, on application to CCDC,
12 Union Road, Cambridge CB2 1EZ, UK (Fax:
+44-1223-336033; E-mail: deposit@ccdc.cam.ac.uk
or www: http://www.ccdc.cam.ac.uk).
Hz, 2H, Ar H), 7.15 (d, 3J(H,H) = 8.0 Hz, 2H,
3
Ar H), 7.22 (m, 4H, Ar H), 8.08 (d, J(H,H) = 8.2
Hz, 2H, Ar H), 8.37 (s, 2H, Ar H), 8.76 (d,
2J(PNH) = 9.5 Hz, 2H, NH). 13C NMR (125.76 MHz,
D6-DMSO, 25◦C, TMS): δ = 20.22 (s, CH3), 120.06
(d, 3J(P,C)cresol = 4.5 Hz), 123.76 (s), 124.00 (d,
3J(P,C)amine = 7.0 Hz), 130.14 (s), 134.14 (s), 137.29
(s), 139.25 (d, 2J(P,C)amine = 8.9 Hz), 142.09 (s),
147.70 (s). 31P NMR (202.46 MHz, D6-DMSO, 25◦C,
H3PO4 external): δ = –2.10 (t, 2J(PNH) = 9.5 Hz).
ACKNOWLEDGMENTS
The authors wish to especially thank Professor
Dr. C.O.D. Ve´dova for providing the computa-
tional time (hardware and software) and his helpful
comments.
N,Nꢁ-Bis(4-aminopyridinyl)
Phosphoramidic
Acid (4-methylphenyl) Ester (9). Yield: 92%;
mp = 224.9◦C. Elemental analysis (%) Calcd: C,
60.00; H, 5.00; N, 16.47. Found: C, 59.99; H, 5.01;
N, 16.48. IR (KBr, cm−1): ν = 3385 (w, NH), 3175
(m), 1597 (s), 1501 (s), 1459 (m), 1400 (w), 1326
(m), 1279 (m), 1240 (m), 1212 (s, P O), 1164 (m),
1000 (s, P N), 974 (m), 942 (s, P N), 812 (m), 557
(w), 501 (m). 1H NMR (500.13 MHz, D6-DMSO,
25◦C, TMS): δ = 2.24 (s, 3H, CH3), 7.05–7.18 (m,
8H, Ar H), 8.26 (m, 4H, Ar H), 9.17 (s, 2H, NH).
13C NMR (125.76 MHz, D6-DMSO, 25◦C, TMS):
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