Synthesis and bio-activity of novel iminophosphoranes

Article abstract of DOI:10.1002/jhet.5570450514

(Chemical Equation Presented) The title compounds (5a-j) were synthesized by a two step process. 4-Chlorophenyl and bis(2-chloroethyl) amino-dibromophosphites (1a and 1b) were reacted with 1,8-diaminonaphthalene (2) to form the diazaphosphinines (3a and 3

Full text of DOI:10.1002/jhet.5570450514

Sep-Oct 2008
1337
Synthesis and Bio-activity of Novel Iminophosphoranes
Ch. Mohan, B. Hari Babu, C. Naga Raju*, C. Suresh Reddy and V. Janardhan Reddy
Department of Chemistry, Sri Venkateswara University, Tirupati-517502, India
E-mail: naga_raju04@yahoo.co.in
Received October 19, 2007
H
N
9
10
11
NH2
NH2
R'
H
Br
Br
THF
N1
8
P
+
R'
N
P
R'
2
P
THF,50-55°C
N2
+
R
N3
2 TEA, N2
13
12
N
H
7
N3
H
+ N2
R
4
6
5
(1a,b)
(2)
(3a,b)
(4a-e)
(5a-j)
The title compounds (5a-j) were synthesized by a two step process. 4-Chlorophenyl and bis(2-
chloroethyl) amino-dibromophosphites (1a and 1b) were reacted with 1,8-diaminonaphthalene (2) to form
the diazaphosphinines (3a and 3b). They were further reacted with different alkyl azides (4a-e) in THF at
50-55 °C under N2 atmosphere to afford the corresponding iminophosphoranes (5a-j). Their structures
were established by elemental analysis, IR, 1H, 13C, 31P NMR and Mass spectral data. All of them exhibited
moderate antibacterial activity.
J. Heterocyclic Chem., 45, 1337 (2008).
INTRODUCTION
triethylamine (TEA) in dry tetrahydrofuran (THF) under
N2 atmosphere at room temperature form the corresponding
trivalent dibromophosphites (1a and 1b). Reaction of 1a and
1b with 1,8-diaminonaphthalene (2) in two moles of TEA
in dry THF under N2 atmosphere affords 2-(4-chloro-
phenoxy)-2,3-dihydro-1H-naphtho[1,8-de][1,3,2]diaza-
phosphinine and N,N-di(2-chloroethyl)-N-(2,3-dihydro-
1H-naphtho[1,8-de][1,3,2]diazaphosphinin-2-yl)amine
(3a and 3b). Different alkyl azides (4a-e) when treated
with 3a and 3b in dry THF at 50-55°C under similar
conditions afforded 5a-j in 64-73% yield. They melt in
the range of 220-252°C. Thin layer chromatography
(TLC) was employed to monitor the reaction progress and
to determine the purity of the products.
Reaction of a tertiary phosphine with an organic azide
to produce an iminophosphorane [1], known as the
Staudinger reaction [2] is a versatile tool in organic
synthesis [3]. Nitrogen mustard derivative of cyclic
organophosphorus compound, such as cyclophosphamide
is known to exhibit antitumour activity [4]. In the primary
imination process, phosphazides are important inter-
mediates that have been isolated [5] or trapped via an
intramolecular reaction [6]. But in most cases such
phosphazides lose nitrogen at room temperature or even at
lower temperature to give the corresponding iminophos-
phoranes in practically quantitative yields. Stable and
isolable phosphazides [7] were formed in the case of
sterically hindered and the electron releasing substituents
on phosphorus and electron decreasing groups on the ꢀ-N
of the azides [8,9]. Iminophosphosharanes play an important
role in heterocyclic synthesis [10-12]. The versatility of
phosphinimines in the synthesis of heterocycles
embedded with high-valent transition metals is well
documented [13]. The asymmetrically substituted
phosphine ligands are also good chelating agents due to
the presence of the phosphine and imine nitrogen electron
rich centres [14].
IR absorptions in the region [15-18] 1220-1235, 1370-
1385, 1020-1035 and 3163-3289 cm-1 are assigned for
P=N, P-N, N-C and P-NH stretching frequencies
respectively.
Naphthalene moiety [15] protons of 5a-j resonated as
three doublets at ꢁ 6.61-6.75 (5 & 10-H, J = 6.2
– 6.8 Hz), 7.31-7.49 (6 & 9-H, J = 7.9-8.1 Hz) and ꢁ
7.21-7.35 (7 & 8-H, J = 7.9-8.3 Hz). The hydrogens of 4-
chloro-phenoxy moiety (5a-j) gave two doublets at ꢁ
7.15-7.25 (2ꢂ & 6ꢂ-H, J = 7.5-8.0 Hz) and ꢁ 7.21-7.41 (3ꢂ
& 5ꢂ-H, J =8.6-9.2 Hz). The –N-CH2-CH2-Cl protons gave
signals as multiplet at ꢁ 2.52-2.75 and the –N-CH2-CH2-
Cl protons resonated as triplet at ꢁ 3.68-3.71 (J = 11.4-
11.7 Hz). The –NH protons [19] resonated as a doublet at
ꢁ 7.98-8.29 (2JP-N-H = 4.0-4.5 Hz) due to coupling with
phosphorus. The alkyl side chain protons exhibited
signals in the expected range [20].
In the course of our studies on six-membered
phosphorus fused heterocycles having externally linked
iminophosphorane moiety from 1,8-diamino naphthalene
by Staudinger reaction, synthesis of the title compounds
(5a-j) has been accomplished.
RESULTS AND DISCUSSION
Compounds 5a, 5d, 5f and 5j exhibited only five 13C
NMR signals [15,20] for the ten naphthalene carbons
because of their symmetrical disposition with respect to
p-Chlorophenol/bis(2-chloroethyl) amine hydrochloride
on reaction with phosphorus tribromide in the presence of

1338
Ch. Mohan, B. H. Babu, C. N. Raju, C. S. Reddy and V. J. Reddy
Vol 45
Scheme 1
H
9
10
11
N
NH2
NH2
R'
Br
Br
H
1
THF
8
N
P
+
R'
N
P
R'
2
THF, 50-55°C
N2
+
R
N3
2 TEA, N2
13
12
P
N
H
7
N3
R
+ N2
4
H
6
5
(1a,b)
(2)
(3a,b)
(4a-e)
(5a-j)
Br
P
P
O
N
C6H4
Cl (4)
,
O
C6H4 Cl (4)
1a = R' =
1b = R' =
3a = R' =
3b = R' =
Br
Br
Br
(CH2-CH2-Cl)2
,
N
(CH2-CH2-Cl)2
Rꢂ
Compd.
R
Compd.
5a,5f
5b,5g
5c,5h
5d,5i
5e,5j
CH(CH3)2
5a-e
5f-j
O-C6H4-Cl(4)
N-(CH2-CH2-Cl)2
CH2-CH=CH2
CH2-CH3
CH2-(CH2)2-CH3
CH2-CH-(CH3)2
eluting system on silica gel (60-120 mesh) and iodine as
visualizing agent. Melting points were determined in open
capillary tubes on Mel-temp apparatus and were corrected.
Microanalysis was performed at CDRI, Lucknow, India. IR
spectra were recorded in KBr pellets on a Nicolet 380 FT double
iminophosphorane system. The N-CH2-CH2-Cl in
compounds 5f and 5j gave doublet at ꢀ 43.0-43.1 (2JPNC
=
9.5-9.6 Hz) and –N-CH2-CH2-Cl resonated at ꢀ 47.4-47.0.
5a and 5d exhibited 13C NMR signals in the expected
region. In the side chain, first carbon of the imino group
(-P=N-C) gave doublet at ꢀ 33.1-33.2 (2JP=N-C = 9.7-10.0
Hz) due to coupling with phosphorus [21].
31P NMR chemical shifts [17,22] (5a-j) appeared in the
region -2.14 to 6.95 ppm.
Compounds 5a, 5d, 5f and 5j exhibited their respective
molecular ions at m/z 370 (19.2, M-1), 383 (14.1, M-2),
384 (60.5, M-1) and 399 (22.8, M+•) in the FAB mass
spectra [15].
beam spectrophotometer
(
ꢀ
in cm-1) in Environmental
Engineering Lab, S.V. University, Tirupati. 1H, 13C and 31P
NMR spectra were recorded at IISc, Bangalore, Bruker AMX
1
400 MHz spectrometer operating at 400 MHz, for H and 100
MHz for 13C, 161.9 MHz for 31P NMR in CD3OD. The H and
1
13C chemical shifts were referenced to tetramethyl silane and 31P
chemical shifts to 85% H3PO4. Mass spectra were recorded on a
Jeol S X 102 DA/600 mass spectrometer using Argon / Xenon (6
keV, 10 mA) as the FAB (fast atom bombardment) gas and also
a Shimadzu QP-2000, GC-MS instrument.
Thus, the combined analytical, IR, NMR and mass
spectral data conclusively agreed with the proposed
structures for the title compounds (5a-j).
Synthesis of butyl azide (4d). In a dry 100 mL round
bottomed flask fitted with dropping funnel, calcium chloride
tube, sodium azide (0.32 g, 0.005 mole) and 10 mL of dry THF
were placed and stirred. Butyl bromide (0.53 g, 0.005 mole) in
100 mL of dry THF was added to it at room temperature.
Temperature of the reaction mixture was raised to 40-45°C
stirred for 3-4 hrs, after cooling to room temperature to remove
sodium bromide. The filtrate was used for the next step reaction.
Synthesis of [2-(4-Chloro-phenoxy)-2,3-dihydro-1H-1,3-diaza-
2ꢁ5-phospha-phenalen -2-ylidene]-butyl-amine (5d). p-Chloro-
phenol (0.57 g, 0.005 mole) in 10 mL of dry THF was added at
0-5°C to phosphorus tribromide (0.909 g, 0.005 mole) in the
presence of TEA (0.005 mole) in dry THF (20 mL) under nitrogen
atmosphere and stirred at room temperature for 2 hrs to form 1a.
The reaction mixture was filtered to remove triethylamine
hydrobromide. To the filtrate a solution of 1,8-diaminonaphthalene
(2) (0.79 g, 0.005 mole) in 20 mL of dry THF was added in the
presence of triethyl amine (0.01 mole) under N2 atmosphere and
the reaction mixture was stirred for two hours to form 2-(4-
chlorophenoxy)-2,3-dihydro-1H-naphtho[1,8-de][1,3,2]diaza-
CONCLUSION
We successfully synthesized a series of novel iminophos-
phoranes in high yields by Staudinger reaction adopting a
simple and straight forward procedure. The advantages are
short reaction times, low cost of the starting chemicals, simple
experimental procedure. These compounds exhibited moderate
antibacterial activity.
EXPERIMENTAL
Solvents were used after purifying them by the established
procedures. Progress of the reactions and purity of the
compounds were monitored by thin layer chromatography
(TLC) using n-hexane and ethyl acetate (1:1 by volume) as

Sep-Oct 2008
Synthesis and Bio-activity of Novel Iminophosphoranes
1339
phosphinine (3a). The reaction mixture was filtered under nitrogen
atmosphere to remove triethylamine hydrobromide. To the filtrate
butyl azide (4d) (0.005 mole) were added at room temperature and
the mixture was stirred at 50-55°C under N2 atmosphere for 2-3
hrs. The solvent was removed in a rotoevaporator. The crude
residue was further purified by column chromatography using
silica gel (60-120 mesh) as adsorbent and hexane and ethyl acetate
(1:1) as an eluent to afford pure iminophosphorane (5d) with yield
2.06 g (66%), mp. 230-232°C. Compounds 5a-c and 5e-j were
prepared by adopting the above procedure.
2.01 g (68%); mp 224-226°C; ir: P=N 1230, P-N 1375, N-C
1027, P-NH 3289 cm-1; 31P nmr: ꢁ 1.12; 1H nmr: ꢁ 6.72 (d, J =
6.2 Hz, 2H, 5 & 10-H), 7.41 (d, J = 7.9 Hz, 2H, 6 & 9-H), 7.31 (d,
J = 8.0 Hz, 2H, 7 & 8-H), 7.15 (d, J = 7.7 Hz, 2H, 2ꢂ & 6ꢂ-H), 7.22
(d, J = 8.9 Hz, 2H, 3ꢂ & 5ꢂ-H), 8.29 (d, J = 4.5 Hz, 2H, P-NH),
2.09-2.02 (m, 2H, -CH2-CH3), 1.24 (t, J = 11.5 Hz, 3H, -CH2-
CH3). Anal. Calcd for C18H17N3POCl: C, 60.42; H, 4.78; N, 11.74.
Found: C, 60.35, H, 4.74; N, 11.70.
Characterization of [2-(4-chloro-phenoxy)-2,3-dihydro-1H-1,3-
diaza-2ꢀ5-phospha-phenalen-2-ylidene]-butyl-amine (5d). This
compound was obtained as brown color needles (ethanol), Yield:
2.06 g (66%); mp 230-232°C; ir: P=N 1225, P-N 1380, N-C
1025, P-NH 3223 cm-1; 31P nmr: ꢁ 6.95; 1H nmr: ꢁ 6.73 (d, J = 6.5
Hz, 2H, 5 & 10-H), 7.43 (d, J = 8.0 Hz, 2H, 6 & 9-H), 7.35 (d, J =
8.3 Hz, 2H, 7 & 8 –H), 7.20 (d, J = 7.9 Hz, 2H, 2ꢂ & 6ꢂ-H), 7.31
(d, J = 8.6 Hz, 2H, 3ꢂ & 5ꢂ-H), 8.28 (d, J = 4.1 Hz, 2H, P-NH),
2.15-2.10 (m, 2H, -CH2-CH2-CH2-CH3), 1.60-1.54 (m, 2H, -CH2-
CH2-CH2-CH3), 1.45-1.40 (m, 2H, -CH2-CH2-CH2-CH3), 0.96 (t, J
= 6.2 Hz, 3H, -CH2-CH2-CH2-CH3); 13C nmr: ꢁ 110.1 (C-5 & C-
10), 128.1 (C-6 & C-9), 122.6 (C-7 & C-8), 129.5 (C-12), 130.1
(C-13), 112.7 (C-4 & C-11), 147.3 (C-1ꢂ), 123.9 (C-2ꢂ & C-6ꢂ),
127.2 (C-3ꢂ & C-5ꢂ), 120.8 (C-4ꢂ), 33.0 (2JPNC=9.9 Hz, -CH2-CH2-
CH2-CH3), 30.7 (J = 5.2 Hz, -CH2-CH2-CH2-CH3), 26.0 (-CH2-
CH2-CH2-CH3), 14.1 (-CH2-CH2-CH2-CH3). ms: m/z 383 (14.1,
M-2), 330 (50.3), 295 (46.2), 250 (76.2), 231 (76.5), 190 (100),
170 (48.5), 120 (85.2), 83 (95.5). Anal. Calcd. for C20H21N3POCl:
C, 62.26; H, 5.48; N, 10.89. Found: C, 62.20; H, 5.44; N, 10.83.
Characterization of [2-(4-chloro-phenoxy)-2,3-dihydro-1H-
1,3-diaza-2ꢀ5-phospha-phenalen-2-ylidene]-isobutyl-amine (5e).
This compound was obtained as brown color prisms (ethanol),
Yield: 2.00 g (64%); mp 235-237°C; ir: P=N 1231, P-N 1382,
N-C 1023, P-NH 3215 cm-1; 31P nmr: ꢁ -2.14; 1H nmr: ꢁ 6.75 (d,
J = 6.7 Hz, 2H, 5 & 10-H), 7.49 (d, J = 8.1 Hz, 2H, 6 & 9-H),
7.34 (d, J = 7.9 Hz, 2H, 7 & 8 –H), 7.25 (d, J = 8.0 Hz, 2H, 2ꢂ &
6ꢂ-H), 7.41 (d, J = 8.8 Hz, 2H, 3ꢂ & 5ꢂ-H), 8.27 (d, J = 4.0 Hz, 2H,
P-NH), 1.75-1.68 (m, 2H, -CH2-CH-(CH3)2), 3.50-3.42 (m, H, -
CH2-CH-(CH3)2), 1.42 (d, J = 13.5 Hz, 6H, (-CH2-CH-(CH3)2).
Anal. Calcd. for C20H21N3POCl: C, 62.26; H, 5.48; N, 10.89.
Found: C, 62.20; H, 5.43; N, 10.84.
Physical, Analytical and Spectral Data for the test
compounds (5a-j).
Characterization of [2-(4-chloro-phenoxy)-2,3-dihydro-1H-
1,3-diaza-2ꢀ5-phosphaphenalen-2-ylidene]-isopropyl-amine (5a).
This compounds was obtained as brown color needles (ethanol),
Yield: 1.98 g (65%), mp 220-222°C; ir: P=N 1235, P-N 1370, N-
C 1020, P-NH 3163 cm-1; 31P nmr: ꢁ 2.98; 1H nmr: ꢁ 6.75 (d, J =
6.3 Hz, 2H, 5 & 10-H), 7.45 (d, J = 8.1 Hz, 2H, 6 & 9-H), 7.34 (d,
J = 8.2 Hz, 2H, 7 & 8-H), 7.18 (d, J = 7.5 Hz, 2H, 2ꢂ & 6ꢂ-H), 7.24
(d, J = 9.2 Hz, 3ꢂ & 5ꢂ-H), 8.27 (d, J = 4.2 Hz, 2H, P-NH), 2.09-
2.00 (m, H, -CH-(CH3)2), 1.50-1.45 (m, 6H, -CH-(CH3)2); 13C
nmr: ꢁ 109.1 (C-5 & C-10), 128.0 (C-6 & C-9), 122.7 (C-7 & C-
8), 130.2 (C-12), 131.3 (C-13), 112.4 (C-4 & C-11), 148.2 (C-1ꢂ),
123.0 (C-2ꢂ & C-6ꢂ), 129.6 (C-3ꢂ & C-5ꢂ), 124.0 (C-4ꢂ), 33.1 (2JPNC
= 9.8 Hz, -CH-(CH3)2), 25.4 (-CH-(CH3)2); ms: m/z 370 (19.2, M-
1), 328 (49.1), 290 (35), 254 (33.3), 203 (66.6), 146 (40.5), 120
(100), 83 (96.1). Anal. Calcd for C19H19N3POCl: C, 61.37; H,
5.15; N, 11.30. Found: C, 61.32; H, 5.11; N, 11.26.
Characterization of [2-(4-chloro-phenyl)-2,3-dihydro-1H-
1,3-diaza-2ꢀ5-phosphaphenalen-2-ylidene]-propenyl-amine (5b).
This compounds was obtained as brown color prisms (ethanol),
Yield: 2.02 g (67%); mp 228-230°C; ir: P=N 1238, P-N 1373, N-C
1022, P-NH 3220 cm-1; 31P nmr: ꢁ 0.31; 1H nmr: ꢁ 6.68 (d, J = 6.4
Hz, 2H, 5 & 10-H), 7.44 (d, J = 8.0 Hz, 2H, 6 & 9-H), 7.27 (d, J =
8.1 Hz, 2H, 7 & 8-H), 7.17 (d, J = 7.8 Hz, 2H, 2ꢂ & 6ꢂ-H), 7.21 (d, J
= 9.0 Hz, 2H, 3ꢂ & 5ꢂ-H), 7.98 (d, J = 4.3 Hz, P-NH), 3.55-3.49 (m,
H, -CH2-CH=CH2), 5.98-5.90 (m, H, -CH2-CH=CH2), 5.22 (d, J =
5.7 Hz, 2H, -CH2-CH=CH2). Anal. Calcd for C19H17N3POCl: C,
61.71; H, 4.63; N, 11.36. Found: C, 61.65; H, 4.60; N, 11.31.
Characterization of 2-[bis-(2-chloro-ethyl)]-(2-isopropyl-
imino-2,3-dihydro-1H-1,3-diaza-2ꢀ5-phosphaphenalen-2-yl)-
amine (5f). This compound was obtained as brown color needles
(ethanol), Yield: 1.88 g (71%); mp 240-242°C; ir: P=N 1222, P-N
Characterization of [2-(4-chloro-phenoxy)-2,3-dihydro-1H-1,3-
diaza-2ꢀ5-phospha-phenalen-2-ylidene]-ethyl-amine (5c). This
compound was obtained as brown color needles (ethanol), Yield:
Table 1
Antibacterial activitya of compounds (5a-j).
Staphylococcus aureus
Bacillus faecalis
Escherichia coli
Klebsiella pneumonia
Compd.
100 μg/mL 200 μg/mL 100 μg/mL 200 μg/mL 100 μg/mL 200 μg/mL 100 μg/mL 200 μg/mL
5a
6
6
6
6
6
7
7
7
7
7
8
9
6
6
12
10
7
6
6
12
8
6
6
10
12
10
13
10
11
6
5b
5c
10
12
10
13
10
10
7
6
6
9
6
5d
6
7
6
10
7
8
5e
6
8
6
6
5f
6
10
14
15
10
10
7
12
8
7
5g
7
6
6
5h
7
6
10
15
10
6
7
5i
5j
7
10
7
7
11
9
9
7
6
Pencillinb
12
11
9
12
aZone of inhibition in mm; bStandard antibacterial compound.

1340
Ch. Mohan, B. H. Babu, C. N. Raju, C. S. Reddy and V. J. Reddy
Vol 45
1
1376, N-C 1039, P-NH 3219 cm-1; 31P nmr: ꢀ 5.14; H nmr: ꢀ 6.68
(d, J = 6.8 Hz, 2H, 5 & 10-H), 7.48 (d, J = 8.0 Hz, 2H, 6 & 9-H),
7.30 (d, J = 8.1 Hz, 2H, 7 & 8-H), 2.75-2.69 (m, 4H, -N-CH2-CH2-
Cl), 3.71 (t, J = 11.6 Hz, 4H, -N-CH2-CH2-Cl), 8.17 (d, J = 4.1 Hz,
2H, P-NH), 2.10-1.98 (m, H, -CH-(CH3)2), 1.61-1.52 (m, 6H, -CH-
(CH3)2). 13C nmr: ꢀ 109.4 (C-5 & C-10), 128.2 (C-6 & C-9), 122.5
(C-7 & C-8), 129.5 (C-12), 130.1 (C-13), 112.4 (C-4 & C-11), 43.0
CH-(CH3)2), 20.2 (-CH2-CH-(CH3)2); ms: m/z (%): 399 (22.8,
M-1), 381 (16.2), 342 (100), 297 (37.8), 222 (32.4), 175 (13.5),
127 (20.5), 97 (35.2). Anal. Calcd. for C18H25N4PCl2; C, 54.14;
H, 6.31; N, 14.03; Found: C, 54.34; H, 6.27; N, 13.98.
Antibacterial Activity. Compounds (5a-j) were screened for
their antibacterial activity (Table 1) against gram positive
bacteria, Staphylococcus aureus, Bacillus faecalis and gram
negative bacteria, Escherichia coli, Klebsiella pneumania by the
disc diffusion method [23,24] in luria bertani nutrient agar
medium at two concentrations (100, 200 μg/mL). The solutions
containing 106 cells/mL were added to each filter paper disc (6
mm diameter) and DMSO was used as the control. The freshly
prepared agar medium containing bacterial species was loaded
to the discs. These plates were incubated at 35°C and examined
for zone of inhibition around each disc after 24 hrs. The results
were compared with the activity of the standard antibiotic (100
μg/mL).
(J = 9.5 Hz, -N-CH2-CH2-Cl), 47.4 (-N-CH2-CH2-Cl), 33.0 (2JPNC
=
10.0 Hz, -CH-(CH3)2), 23.7 (-CH-(CH3)2); ms: m/z 384 (60.5, m-1),
350 (46.5), 321 (55.2), 273 (68.4), 208 (100), 178 (20.5), 120
(80.3), 87 (24.5). Anal. Calcd. for C17H23N4PCl2; C, 52.99; H, 6.01;
N, 14.54; Found: C, 52.93; H, 5.57; N, 14.50.
Characterization of 2-[bis-(2-chloro-ethyl)]-(2-propenyl-
imino-2,3-dihydro-1H-1,3-diaza-2ꢁ5-phosphaphenalen-2-yl)-
amine (5g). This compound was obtained as brown color needles
(ethanol), Yield: 1.80 g (70%); mp 245-247°C; ir: 1229 (P=N),
1374 (P-N), 1034 (N-C), 3203 (P-NH) cm-1; 31P nmr: ꢀ 0.22; 1H
nmr: ꢀ 6.63 (d, J = 6.9 Hz, 2H, 5 & 10-H), 7.42 (d, J = 7.9 Hz,
2H, 6 & 9-H), 7.24 (d, J = 8.3 Hz, 2H, 7 & 8-H), 2.62-2.54 (m,
4H, -N-CH2-CH2-Cl), 3.71 (t, J = 11.7 Hz, 4H, -N-CH2-CH2-Cl),
8.18 (d, J = 4.2 Hz, 2H, P-NH), 3.58-3.47 (m, 2H, -CH2-
CH=CH2), 6.03-5.94 (m, H, -CH2-CH=CH2), 5.31 (d, J = 5.8 Hz,
2H, -CH2-CH=CH2). Anal. Calcd. for C17H21N4PCl2; C, 53.27;
H, 5.52; N, 14.61; Found: C, 53.20; H, 5.48; N, 14.56.
Characterization of 2-[bis-(2-chloro-ethyl)]-(2-ethylimino-
2,3-dihydro-1H-1,3-diaza-2ꢁ5-phosphaphenalen-2-yl)-amine
(5h). This compound was obtained as brown color prisms
(ethanol), Yield: 1.85 g (72%); mp 250-252°C; ir: P=N 1223, P-
N 1384, N-C 1039, P-NH 3280 cm-1; 31P nmr: ꢀ 1.16; 1H nmr: ꢀ
6.62 (d, J = 6.4 Hz, 2H, 5 & 10-H), 7.32 (d, J = 8.0 Hz, 2H, 6 &
9-H), 7.30 (d, J = 7.9 Hz, 2H, 7 & 8-H), 2.60-2.52 (m, 4H, -N-
CH2-CH2-Cl), 3.68 (t, J = 11.5 Hz, 4H, -N-CH2-CH2-Cl), 8.15
(d, J = 4.0 Hz, 2H, P-NH), 2.08-2.00 (m, 2H, -CH2-CH3), 1.30
(t, J = 11.6 Hz, 3H, -CH2-CH3). Anal. Calcd. for C16H21N4PCl2;
C, 51.76; H, 5.70; N, 15.09; Found: C, 51.70; H, 5.65; N, 15.03.
Characterization of 2-[bis-(2-chloro-ethyl)]-(2-butylimino-
2,3-dihydro-1H-1,3-diaza-2ꢁ5-phosphaphenalen-2-yl)-amine
(5i). This compound was obtained as brown color needles
(ethanol), Yield: 1.94 g (71%); mp 244-246°C; ir: P=N 1220,
P-N 1382, N-C 1035, P-NH 3283 cm-1; 31P nmr: ꢀ 0.21; 1H nmr: ꢀ
6.62 (d, J = 6.5 Hz, 2H, 5 & 10-H), 7.31 (d, J = 7.9 Hz, 2H, 6 & 9-
H), 7.23 (d, J = 8.2Hz, 2H, 7 & 8-H), 2.61-2.53 (m, 4H, -N-CH2-
CH2-Cl), 3.69 (t, J = 11.4 Hz, 4H, -N-CH2-CH2-Cl), 8.12 (d, J =
4.1 Hz, 2H, P-NH), 2.09-2.03 (m, 2H, -CH2-CH2-CH2-CH3), 1.78-
1.72 (m, 2H, -CH2-CH2-CH2-CH3), 1.48-1.41 (m, 2H, -CH2-CH2-
CH2-CH3), 0.95 (t, J = 6.3 Hz, 3H, -CH2-CH2-CH2-CH3). Anal.
Calcd. for C18H25N4PCl2; C, 54.41; H, 6.31; N, 14.03; Found: C,
54.34; H, 6.26; N, 13.97.
All the compounds 5a-j exhibited moderate antibacterial
activity, but 5i showed more antibacterial activity against
Escherichia coli when compared to that of the standard.
Acknowledgements. The authors thank Prof. C.
Devendranath Reddy and Dr. C. Suresh Reddy, Sri
Venkateswara University, Tirupati, for their encouragement and
the Directors of CDRI, Lucknow and SIF, IISc, Bangalore, for
the elemental analysis and spectral data.
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amine (5j). This compound was obtained as brown color prisms
(ethanol), Yield: 2.00 g (73%); mp 247-249°C; ir: P=N 1226, P-
N 1385, N-C 1031, P-NH 3282 cm-1; 31P nmr: ꢀ 0.99; 1H nmr: ꢀ
6.61 (d, J = 6.6 Hz, 2H, 5 & 10-H), 7.33 (d, J = 8.0 Hz, 2H, 6 &
9-H), 7.21 (d, J = 8.1 Hz, 2H, 7 & 8-H), 2.61-2.54 (m, 4H, -N-
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Synthesis and Bio-activity of Novel Iminophosphoranes
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