Synthesis of some novel annelated 1,2,3-selena/thiadiazoles and 2H-diazaphospholes

Article abstract of DOI:10.1002/jhet.5570400120

A number of annelated heterocyclic indene derivatives having 1,2,3-selena/thiadiazole and 2H-1,2,3-diazaphosphole rings have been synthesized by exploiting the α-ketomethylene functionality in some novel 1-methyl-piperidin-4-ones and 1-oxo-tetrahydrothiop

Full text of DOI:10.1002/jhet.5570400120

Jan-Feb 2003
Synthesis of Some Novel Annelated 1,2,3-Selena/Thiadiazoles
and 2H-Diazaphospholes
149
Venkatapuram Padmavathi* [a], Tippireddy Venkat Ramana Reddy [b],
b
a
Kamireddy Audisesha Reddy and Dandu Bhaskar Reddy
[a] Department of Chemistry, Sri Venkateswara University, Tirupati -517 502, India
[b] Chemical Laboratory, SPROB, SHAR Centre / ISRO / DOS, Sriharikota -524 121, India
Received March 13, 2002
A number of annelated heterocyclic indene derivatives having 1,2,3-selena/thiadiazole and 2H-1,2,3-
diazaphosphole rings have been synthesized by exploiting the α-ketomethylene functionality in some novel
1-methyl-piperidin-4-ones and 1-oxo-tetrahydrothiopyran-4-ones and were characterized by their physical
and spectral data.
J. Heterocyclic Chem., 40, 149 (2003).
Molecules with heteroaromatic rings are widely distrib-
(2), (2R,3S,6S)-2,6-diaryl-3-methyltetrahydrothiopyran-4-
one (3) and (2R,3S,6S)-1-oxo-2,6-diaryl-3-methyl-
tetrahydrothiopyran-4-one (4) were obtained predomi-
nantly. The conformations of these compounds were fur-
ther ascertained on the basis of their NMR data explained
below [5,8].
uted in nature. Indeed a number of heterocyclic com-
pounds containing nitrogen, sulfur and other heteroatoms
exhibit a variety of biological activity. The concept of
isosteric exchange is a tool for modifying the activity of
biologically important molecules. One such isosteric pair
constitutes sulfur and selenium. Recently a great deal of
interest is envisaged in annelated heterocycles. In fact,
some bicyclic annelated 1,2,3–selena/thiadiazoles and
diazaphospholes were found to be potential bioactive
agents [1]. Although, we have been actively involved for
quite some time in the synthesis of a variety of hetero-
cycles, in the recent past, however, we have diverted our
attention to annelated heterocycles, particularly
1,2,3–selena/thiadiazole rings fused to carbocyclic [2] and
heterocyclic [3] systems. The attraction to this is multi-
faceted with the main reason being that this process had
received scant attention in the literature and in addition we
wished to extend this methodology to the synthesis of a
wide range of annelated heterocycles. Therefore, in con-
tinuation of our efforts herein we report some novel 1,2,3-
selena/thiadiazoles and 2H-1,2,3-diazaphospholes fused
to 1-methyl-piperidin-4-ones and 1-oxo-tetrahydrothiopy-
ran-4-ones.
Scheme 1
-1
The Infrared spectra (ν, cm ) of 2 showed medium-to-
strong bands in the region 2765-2775 (N-Me), 1720-1725
(C=O) and at 1040-1055 (S=O), 1710-1720 (C=O) for 4.
1
In the H NMR spectra (δ, ppm and J, Hz) of 2, the proton
at C displayed a doublet between 3.00-3.06 (J ≈ 10.3)
2
The precursor ketones 1,3-dimethyl-2-phenyl-6-aryl-
piperidin-4-ones (2), 3-methyl 2-phenyl-6-aryl-tetrahy-
drothiopyran-4-ones (3) and 3-methyl-1-oxo-2-phenyl-6-
aryltetrahydrothiopyran-4-ones (4) were prepared from 2-
methyl-1-phenyl-5-aryl-1,4-pentadien-3-ones (1). The
condensation of 1 with methylamine in dimethylfor-
mamide [4] gave 2. Compound 3 was prepared by passing
owing to AB splitting pattern, while proton at C exhibited
3
a quintet or multiplet in the region 2.78-2.93. The
observed coupling constant J = 10.3 Hz certainly suggest
that the phenyl group and methyl group are in equatorial
positions. The C protons showed a doublet of doublet
5
around 2.55-2.61 (J ≈ 14.8, 3.3) and a triplet between 2.80-
2.94, whereas the proton at C exhibited a doublet of dou-
6
H S into a refluxing solution of 1 in ethanol in presence of
blet in the region 3.39-3.46 (J ≈ 14.5, 3.0) pertaining to an
ABX splitting pattern. The coupling constants J = 14.5 &
2
sodium acetate (2 fold) for 15-18 hours [5] and S-oxida-
tion of 3 with N-bromosuccinimide [6] resulted 4. (see
Scheme 1 and Table 1). The sulphoxides were prepared
generally from sulphides by a variety of reagents as single
or mixture of isomers [7]. However, it was observed that,
N-bromosuccinimide in tetrahydrofuran at room tempera-
ture yielded sulphoxides in high yield. In all these cases,
although isomeric products could be possible, the isomers
(2R,3S,6S)-1-methyl-2,6-diaryl-3-methylpiperidin-4-one
3.0 Hz which are typical for vicinal couplings J
and
anti
J
in the chair conformation indicate that the proton at
gauche
1
C is in axial position. The H NMR spectra of 3 is in
6
accordance with reported values [5]. A similar splitting
pattern was observed for 4, whose protons showed reso-
nance signals around 3.82-3.87 (d, J ≈ 10.8, C ), 3.14-3.35
2
(m, C and C ), 3.04-3.08 (dd, J ≈ 14.3, 3.6, C ) and
3
5-ax
5-eq
4.08-4.18 (dd, J ≈ 14.6, 3.5, C ). Thus 2, 3 and 4 exist in
6

150
V. Padmavathi, T. V. R. Reddy, K. A. Reddy and D. B. Reddy
Vol. 40
Table 1
occupy either axial or equatorial positions, but the axial
orientation is preferred as such a disposition on the sulfur
in a six membered ring is the energetically favoured con-
formation [10]. Thus, the thermodynamically more stable
Physical Data of Compounds 2, 3, 4 and 7 – 12
Compd. Yield M. P.
Mol. Formula
(Mol. Wt.)
Calcd. (Found) (%)
No
(%)
(°C)
C
H
N
isomer was preferred in each case, among the possible
13
stereoisomers. The δ values obtained in their C NMR
C
2a
2b
52 131-132 ( lit. [14] mp 130-131)
spectra are shown in Table 2.
45 145-147
C
H
NO
77.64 7.49
4.53
20 23
2
(309.4)
(77.83) (7.44) (4.42)
72.72 6.42 4.46
(72.86) (6.50) (4.35)
2c
48 163-165
C H ClNO
19 20
(313.8)
3a
3b
3c
4a
30 124-125 ( lit. [5] mp 123-125)
25 142-144 ( lit. [5] mp 145-146)
28 139-140 ( lit. [5] mp 137-138)
88 185-187
82 171-173
80 198-200
55 158-160
58 150-152
50 171-173
60 168-170
55 180-182
56 210-212
62 156-158
60 164-166
57 180-182
54 200-202
50 186-188
52 190-192
60 175-177
56 161-163
53 158-160
59 182-184
57 193-195
54 218-220
C
H
O S
72.45 6.08
(72.57) (6.15)
69.48 6.14
(69.30) (6.05)
64.95 5.15
(65.11) (5.23)
61.96 5.20 11.41
(61.85) (5.26) (11.28)
60.30 5.31 10.55
(60.45) (5.38) (10.40)
56.66 4.50 10.43
(56.49) (4.61) (10.60)
55.81 4.16
(55.75) (4.10) (7.13)
54.67 4.35 6.71
(54.58) (4.44) (6.59)
51.25 3.58 6.64
(51.39) (3.65) (6.55)
70.99 5.96 13.07
(71.16) (6.03) (12.83)
68.35 6.02 11.96
(68.56) (6.13) (11.79)
64.12 5.10 11.81
(63.92) (5.18) (11.62)
63.50 4.74
(63.63) (4.80) (8.09)
61.59 4.90 7.56
(61.41) (4.82) (7.69)
57.67 4.03 7.47
(57.83) (4.10) (7.30)
75.55 6.09 10.57
(75.33) (6.00) (10.48)
73.58 6.13
(73.30) (6.24) (9.71)
69.52 5.37 9.73
(69.29) (5.25) (9.51)
69.21 5.08 6.73
(69.42) (5.13) (6.84)
67.25 5.19 6.27
(67.03) (5.11) (6.18)
63.93 4.47 6.21
(64.13) (4.53) (6.06)
-
-
-
18 18
2
(298.4)
4b
C H O S
19 20 3
(328.4)
4c
C H ClO S
18 17 2
(332.9)
7a
C
H
N Se
19 19
3
(368.3)
Figure 1
7b
C H N Ose
20 21 3
(398.4)
7c
C H ClN Se
19 18 3
The presence of α-ketomethylene functionality in these
1-hetera-4-cyclohexanones served as building block for the
development of annelated heterocycles. Compounds 2 and
4, on reaction with semicarbazide and phenylhydrazine,
gave their respective semicarbazones (5) and phenyl hydra-
zones (6). The oxidative cyclization of the semicarbazones
(5) with selenium dioxide in acetic acid at 60-70 °C [11]
furnished 5,7-dimethyl-4-aryl-6-phenyl-4,5,6,7-tetrahydro-
3-selena-1,2,5-triazaindene (7) and 7-methyl-4-aryl-6-
phenyl-6,7-dihydro-4H-5-thia-3-selena-1,2-diazaindene-5-
oxide (8). However, the Hurd-Moori reaction process with
excess thionylchloride in dichloromethane at 0 °C [12] pro-
duced 5,7-dimethyl-4-aryl-6-phenyl-4,5,6,7-tetrahydro-3-
thia-1,2,5-triazaindene (9) and 7-methyl-4-aryl-6-phenyl-
6,7-dihydro-4H-3,5-dithia-1,2-diazaindene-5-oxide (10).
On the other hand, when 6 was subjected to the cyclization
process with phosphorous trichloride in dry ether in the
presence of triethylamine at -5 to –10 °C [13] 5,7-dimethyl-
4-aryl-2,6-diphenyl-4,5,6,7-tetrahydro-2H-1,2,5-triaza-3-
phosphaindene (11) and 7-methyl-4-aryl-2,6-diphenyl-
2,4.6,7-tetrahydro-5-thia-2H-1,2-diaza-3-phosphaindene-
5-oxide (12) resulted.
(402.8)
8a
C
H
N OSSe
7.23
18 16
2
(387.4)
8b
C
H
N O SSe
19 18
2 2
(417.4)
8c
C H ClN OSSe
18 15 2
(421.8)
9a
C H N S
19 19 3
(321.4)
9b
C H N OS
20 21 3
(351.5)
9c
C
H
ClN S
19 18
3
(355.9)
10a
10b
10c
11a
11b
11c
12a
12b
12c
C
H
N OS
2
8.23
18 16
2
(340.5)
C
H N O S
19 18 2 2 2
(370.5)
C
H ClN OS
18 15 2 2
(374.9)
C
H N P
25 24 3
(397.5)
C
H
N OP
9.83
26 26
3
(427.5)
C
H
ClN P
25 23
3
(431.9)
C
H N OPS
24 21 2
(416.5)
Compound 5 displayed bands between 3220-3440
C
H N O PS
25 23 2 2
(446.5)
(NHCO and CONH ), 1685-1695 and 1555-1570
2
C
H ClN OPS
24 20 2
(CONH ) and 1635-1650 (C=N) for semicarbazone moi-
2
(450.9)
ety, while bands in the region 3280-3300 (NH) and 1590-
1605 (C=N) are due to the phenylhydrazone moiety of 6.
The absence of bands due to semicarbazone unit and the
presence of bands at 1430-1455 (N=N) and 680-735 (C-
S/Se) indicate that cyclization indeed has taken place in 7 -
10. Similarly, the absence of NH band and the presence of
bands around 1580-1600 (C=N) confirmed the formation
the preferred chair conformation with cis-orientation at C ,
2
C and trans at C , C (Figure -1).
6
2
3
However, the N-methyl orientation in 2 can be in equa-
torial or axial position as shown in figure-1. The equator-
ial N-Me is more preferred since the substituents at 1 and 3
positions would be in the stable 1,3-cis-orientation [9]. On
the other hand, the oxygen atom on sulfur in 4 should also
1
of diazaphospholes, 11 and 12. The H NMR spectra of 7
- 12 differ very much from that of 2 and 4. Three different

Jan-Feb 2003
Some Novel Annelated 1,2,3-Selena/Thiadiazoles and 2H-Diazaphospholes
151
Table 2
NMR Spectral Data of Compounds 2, 4 and 7 – 12
1
13
No.
H NMR (δ, ppm)
C NMR (δ, ppm)
2a
0.78 (d, 3H, CH , J=6.6 Hz), 1.75 (s, 1H, N-CH ), 2.55 (dd, 1H, H -5,
10.35 (CH ), 41.15 (NCH ), 49.52 (C ), 51.21 (C ), 70.26
3 3 5 3
3
3
eq
J= 14.8, 3.3 Hz), 2.82 - 2.93 (m, 2H, H -5 & H-3), 3.01 (d, 1H, H-2,
(C ), 77.88 (C ), 208.53 (C ).
ax
6 2 4
J=10.3 Hz) 3.43 (dd, 1H, H-6, J=14.5, 3.5 Hz), 7.24 -7.45 (m, 10H,
Ar-H).
2b
0.84 (d, 3H, CH , J=6.8 Hz), 1.73 (s, 1H, N-CH ), 2.61 (dd, 1H,
10.80 (CH ), 41.22 (NCH ), 49.18 (C ), 51.67 (C ), 55.34
3 3 5 3
3
3
H
-5, J= 14.5, 3.4 Hz), 2.81 (q, 1H, H-3), 2.94 (t, 1H, H -5), 3.08
(OCH ), 70.63 (C ), 78.02 (C ), 207.36 (C ).
eq
ax
3 6 2 4
(d, 1H, H-2, J=10.1 Hz) 3.49 (dd, 1H, H-6, J=14.2, 3.8 Hz), 3.80 (s,
3H, OCH ), 6.85-7.38 (m, 9H, Ar-H).
3
2c
4a
4b
4c
0.82 (d, 3H, CH , J=6.6 Hz), 1.76 (s, 1H, N-CH ), 2.56 (dd, 1H, H -5,
10.44 (CH ), 41.08 (NCH ), 49.35 (C ), 51.82 (C ), 70.38
3 3 5 3
3
3
eq
J= 14.7, 3.3 Hz), 2.80-2.91 (m, 2H, H-3 & H -5), 3.12 (d, 1H, H-2,
(C ), 77.64 (C ), 208.13 (C ).
ax
6 2 4
J=10.2 Hz) 3.56 (dd, 1H, H-6, J=14.4, 3.1 Hz), 7.06-7.43 (m, 9H, Ar-H).
1.04 (d, 3H, CH , J=6.9 Hz), 3.08 (dd, 1H, H -5, J= 14.3, 3.8 Hz), 3.21
12.48 (CH ), 50.87 (C ), 52.92 (C ), 60.70 (C ), 66.88 (C ),
3 3 5 6 2
3
eq
(q, 1H, H-3), 3.32 (t, 1H, H -5), 4.12 (d, 1H, H-2, J=9.4 Hz) 4.32 (dd,
209.75 (C ).
ax
4
1H, H-6, J=14.5, 3.6 Hz), 7.09-7.32 (m, 10H, Ar-H).
1.01 (d, 3H, CH , J=6.6 Hz), 2.97 (dd, 1H, H -5, J= 14.2, 3.6 Hz), 3.14
12.65 (CH ), 50.65 (C ), 52.49 (C ), 54.99 (OCH ), 61.85
3 3 5 3
3
eq
-3.30 (m, 2H, H-3 & H -5), 3.73 (s, 3H, OCH ), 4.07 (d, 1H, H-2,
(C ), 66.32 (C ), 208.98 (C ).
ax
3
6 2 4
J=9.2 Hz) 4.40 (dd, 1H, H-6, J=14.7, 3.8 Hz), 6.74-7.31 (m, 9H, Ar-H).
1.08 (d, 3H, CH , J=6.8 Hz), 3.04 (dd, 1H, H -5, J= 14.4, 3.7 Hz), 3.16
12.60 (CH ), 50.53 (C ), 52.73 (C ), 61.13 (C ), 65.92 (C ),
3
eq
3
3
5
6
2
-3.34 (m, 2H, H-3 & H -5), 4.10 (d, 1H, H-2, J=9.2 Hz) 4.43 (dd, 1H,
210.02 (C ).
ax
4
H-6, J=14.5, 3.6 Hz), 6.85-7.30 (m, 9H, Ar-H).
7a
7b
1.39 (d, 3H, CH , J=6.6 Hz), 1.89 (s, 3H, NCH ), 3.25 (d, 1H, H-6, J=9.6
17.58 (CH ), 39.45 (C ), 41.60 (NCH ), 70.14 (C ), 74.61
3 7 3 4
3
3
Hz), 3.62-3.67 (m, 1H, H-7), 4.57 (s, 1H, H-4), 7.23-7.44 (m, 10H, Ar-H).
1.33 (d, 3H, CH , J=6.8 Hz), 1.91 (s, 3H, NCH ), 3.32 (d, 1H, H-6,
(C ), 143.50 (C ), 152.56 (C ).
6 9 8
17.40 (CH ), 40.07 (C ), 41.68 (NCH ), 55.26 (OCH ), 69.73
3
3
3
7
3
3
J=9.5 Hz), 3.60-3.66 (m, 1H, H-7), 3.83 (s, 3H, OCH ), 4.48 (s, 1H,
(C ), 74.22 (C ), 145.03 (C ), 151.92 (C ).
3
4 6 9 8
H-4), 6.91-7.39 (m, 9H, Ar-H).
7c
8a
8b
8c
9a
1.42 (d, 3H, CH , J=6.6 Hz), 1.86 (s, 3H, NCH ), 3.20 (d, 1H, H-6, J=9.5
Hz), 3.57-3.64 (m, 1H, H-7), 4.51 (s, 1H, H-4), 7.02-7.41 (m, 9H, Ar-H).
17.32 (CH ), 39.71 (C ), 41.77 (NCH ), 69.48 (C ), 75.06
3 7 3 4
3
3
(C ), 142.62 (C ), 151.72 (C ).
6 9 8
1.45 (d, 3H, CH , J=6.8 Hz), 3.50-3.58 (m, 1H, H-7), 4.20 (d, 1H, H-6,
17.45 (CH ), 40.73 (C ), 59.21 (C ), 65.05 (C ), 144.23 (C ),
3 7 4 6 9
3
J=9.0 Hz), 4.60 (s, 1H, H-4), 7.11-7.36 (m, 10H, Ar-H).
151.43 (C ).
8
1.38 (d, 3H, CH , J=6.5 Hz), 3.46-3.52 (m, 1H, H-7), 3.78 (s, 3H, OCH ),
17.36 (CH ), 41.32 (C ), 54.86 (OCH ), 60.44 (C ), 65.56
3 7 3 4
3
3
4.26 (d, 1H, H-6, J=9.2 Hz), 4.66 (s, 1H, H-4), 6.80-7.28 (m, 9H, Ar-H).
(C ), 143.02 (C ), 153.08 (C ).
6 9 8
1.40 (d, 3H, CH , J=6.6 Hz), 3.52-3.59 (m, 1H, H-7), 4.21 (d, 1H, H-6,
17.52 (CH ), 40.98 (C ), 60.85 (C ), 64.88 (C ), 145.11 (C ),
3 7 4 6 9
3
J=9.0 Hz), 4.75 (s, 1H, H-4), 6.84-7.32 (m, 9H, Ar-H).
152.75 (C ).
8
1.25 (d, 3H, CH , J=6.5 Hz), 1.83 (s, 3H, NCH ), 3.18 (d, 1H, H-6,
16.73 (CH ), 40.22 (C ), 41.53 (NCH ), 69.86 (C ), 74.02
3 7 3 4
3
3
J=9.8 Hz), 3.55-3.62 (m, 1H, H-7), 4.51 (s, 1H, H-4), 7.25-7.51 (m,
(C ), 140.42 (C ), 151.56 (C ).
6 9 8
10H, Ar-H).
9b
1.22 (d, 3H, CH , J=6.6 Hz), 1.88 (s, 3H, NCH ), 3.23 (d, 1H, H-6,
16.58 (CH ), 39.29 (C ), 41.43 (NCH ), 56.12 (OCH ), 70.23
3 7 3 3
3
3
J=9.5 Hz), 3.48-3.56 (m, 1H, H-7), 3.77 (s, 3H, OCH ), 4.32 (s, 1H,
(C ), 74.61 (C ), 138.85 (C ), 150.83 (C ).
3
4 6 9 8
H-4), 6.80-7.37 (m, 9H, Ar-H).
9c
1.29 (d, 3H, CH , J=6.5 Hz), 1.85 (s, 3H, NCH ), 3.11 (d, 1H, H-6, J=9.7
17.04 (CH ), 39.86 (C ), 41.61 (NCH ), 69.92 (C ), 74.73
3 7 3 4
3
3
Hz), 3.54-3.60 (m, 1H, H-7), 4.40 (s, 1H, H-4), 6.96-7.42 (m, 9H, Ar-H).
(C ), 141.05 (C ), 150.27 (C ).
6 9 8
10a
10b
10c
11a
11b
1.31 (d, 3H, CH , J=6.6 Hz), 3.45-3.52 (m, 1H, H-7), 4.28 (d, 1H, H-6,
J=9.0 Hz), 4.73 (s, 1H, H-4), 7.18-7.44 (m, 10H, Ar-H).
17.01 (CH ), 39.86 (C ), 61.83 (C ), 67.13 (C ), 141.13 (C ),
3 7 4 6 9
3
150.21 (C ).
8
1.37 (d, 3H, CH , J=6.7 Hz), 3.41-3.47 (m, 1H, H-7), 3.74 (s, 3H, OCH ),
16.72 (CH ), 41.02 (C ), 55.80 (OCH ), 61.35 (C ), 66.48
3 7 3 4
3
3
4.20 (d, 1H, H-6, J=9.2 Hz), 4.82 (s, 1H, H-4), 6.92-7.35 (m, 9H, Ar-H).
(C ), 139.75 (C ), 151.14 (C ).
6 9 8
1.28 (d, 3H, CH , J=6.5 Hz), 3.38-3.44 (m, 1H, H-7), 4.36 (d, 1H, H-6,
17.35 (CH ), 40.71 (C ), 61.02 (C ), 66.64 (C ), 140.73 (C ),
3 7 4 6 9
3
J=8.9 Hz), 4.70 (s, 1H, H-4), 6.88-7.32 (m, 9H, Ar-H).
150.83 (C ).
8
1.31 (d, 3H, CH , J=6.4 Hz), 1.85 (s, 3H, NCH ), 3.20 (d, 1H, H-6, J=9.6
16.95 (CH ), 38.73 (C ), 41.67 (NCH ), 67.93 (C ), 75.22
3 7 3 4
3
3
Hz), 3.51-3.58 (m, 1H, H-7), 4.32 (s, 1H, H-4), 7.20-7.46 (m, 15H, Ar-H).
1.35 (d, 3H, CH , J=6.6 Hz), 1.78 (s, 3H, NCH ), 3.25 (d, 1H, H-6,
(C ), 148.35 (C ), 166.79 (C , J =52 Hz).
6 8 9 CP
17.14 (CH ), 39.31 (C ), 41.75 (NCH ), 55.62 (OCH ), 67.34
3
3
3
7
3
3
J=9.7 Hz), 3.45-3.50 (m, 1H, H-7), 3.72 (s, 3H, OCH ), 4.24 (s, 1H,
(C ), 74.86 (C ), 149.02 (C ), 164.55 (C , J =53 Hz).
3
4 6 8 9 CP
H-4), 7.06-7.42 (m, 14H, Ar-H).
11c
12a
12b
12c
1.33 (d, 3H, CH , J=6.4 Hz), 1.83 (s, 3H, NCH ), 3.28 (d, 1H, H-6, J=9.8
Hz), 3.44-3.49 (m, 1H, H-7), 4.35 (s, 1H, H-4), 6.92-7.40 (m, 14H, Ar-H).
16.78 (CH ), 39.38 (C ), 41.72 (NCH ), 66.88 (C ), 75.50
3 7 3 4
3
3
(C ), 148.27 (C ), 167.32 (C , J =50 Hz).
6 8 9 CP
1.36 (d, 3H, CH , J=6.6 Hz), 3.46-3.52 (m, 1H, H-7), 4.32 (d, 1H, H-6,
17.62 (CH ), 40.92 (C ), 60.84 (C ), 67.18 (C ), 149.23 (C ),
3 7 4 6 8
3
J=9.2 Hz), 4.72 (s, 1H, H-4), 7.10-7.43 (m, 15H, Ar-H).
164.95 (C , J =54 Hz).
9 CP
1.30 (d, 3H, CH , J=6.5 Hz), 3.50-3.56 (m, 1H, H-7), 3.70 (s, 3H, OCH ),
17.03 (CH ), 41.37 (C ), 55.83 (OCH ), 61.56 (C ), 66.94
3 7 3 4
3
3
4.25 (d, 1H, H-6, J=9.0 Hz), 4.67 (s, 1H, H-4), 6.98-7.42 (m, 14H, Ar-H).
(C ), 147.54 (C ), 166.87 (C , J =52 Hz).
6 8 9 CP
1.32 (d, 3H, CH , J=6.7 Hz), 3.43-3.50 (m, 1H, H-7), 4.21 (d, 1H, H-6,
17.75 (CH ), 41.03 (C ), 61.32 (C ), 67.54 (C ), 148.58 (C ),
3 7 4 6 8
3
J=9.0 Hz), 4.80 (s, 1H, H-4), 6.95-7.40 (m, 14H, Ar-H).
163.27 (C , J =53 Hz).
9 CP

152
V. Padmavathi, T. V. R. Reddy, K. A. Reddy and D. B. Reddy
Vol. 40
was checked by TLC using silica gel ‘G’ (Merck) and ethyl
acetate – hexane, 1: 4 as eluents. Elemental analyses were per-
formed using a Perkin-Elmer 240C elemental analyzer. IR spec-
tra were plotted on Perkin-Elmer 1600 series FT-IR instrument
-1
using KBr discs and wave numbers were in cm . NMR spectra
were recorded on a Brucker DPX 300 spectrometer in CDCl
3
solution. The chemical shifts (δ) were measured in ppm using
1
13
TMS as internal standard for H and C NMR and 85%
31
Phosphoric acid (external) for P NMR.
The unsaturated ketones, 2-methyl-1-phenyl-5-aryl-1,4-penta-
dien-3-one (1) and (2R,3S,6S)-2,6-diaryl-3-methyltetrahydro-
thiopyran-4-one (3) were prepared according to the literature pro-
cedures [5].
General Procedure.
1,3-Dimethyl-2-phenyl-6-aryl-piperidin-4-ones (2).
To a well stirred solution of 1 (15 mmoles) in dimethylfor-
mamide (30 mL), 40% aqueous methylamine (20 mmoles) was
added during a period of 30 minutes and stirring was continued
for 25-30 hours at ambient temperature. The reaction mixture
was then poured onto crushed ice and the separated solid was col-
lected by filtration. The crude product was triturated with
ethanol, filtered, dried and recrystallised from ethanol.
sets of signals were observed for all the methine protons.
In compounds 7, 9 and 11, a doublet around 3.17–3.31 (J
General Procedure.
3-Methyl-1-oxo-2-phenyl-6-aryl-tetrahydrothiopyran-4-ones (4).
≈ 9.5) was attributed to proton at C , a multiplet between
6
3.44 – 3.67 was due to proton at C and a singlet in the
To an ice-cold solution of 3 (10 mmoles) in 2:1 tetrahydrofu-
ran-methanol (25 mL), N-bromosuccinimide (12 mmoles) was
added in portions. After 20 minutes, water (1 mL) was added and
mixture was stirred for 3-4 hours. The contents were poured onto
crushed ice. The separated solid was collected by filtration, dried
and recrystallised from alcohol-benzene mixture.
7
downfield region 4.40-4.57 was assigned to a proton at C .
4
Similarly, in the spectra of 8, 10 and 12, the δ values in
H
the regions 4.21–4.36 (d, J ≈ 9.3), 3.38–3.59 (m) and
4.70–4.88 (s) were due to the protons at C , C and C
6
7
4
1
respectively. Thus based on H NMR data, the two aryl
substituents at C and C , the methyl at C and N-Me/S=O
General Procedure.
4
6
7
groups were in the preferred equatorial positions of the
half–chair conformation of heteracyclohexene moiety as in
2 and 4. Furthermore, the 1,2,3-selenadiazole/thiadiazole/
diazaphosphole ring would also be almost in the average
plane as that of the heteracyclohexene moiety according to
Semicarbazones of 2 and 4 (5).
A mixture of 2 or 4 (10 mmoles), semicarbazide hydrochloride
(12 mmoles) and sodium acetate (15 mmoles) in ethanol (20 mL)
was refluxed while stirring for 2-3 hours. The contents were cooled
and poured onto ice-cold water. The separated solid was collected
by filtration, washed, dried and recrystallised from alcohol.
13
the Drieding model ( Figure 2). The C NMR spectral
31
data of these are given in Table 2. The P NMR spectra of
General Procedure.
11 and 12 displayed a signal between −205 and −210 ppm
due to the dicoordinated phosphorous in evidence of the
2H-diazaphosphole ring formation.
Phenyl Hydrazones of 2 and 4 (6).
To a solution of 2 or 4 (5 mmoles) in ethanol (15 mL), phenyl
hydrazine hydrochloride (7 mmoles) and sodium acetate (0.5 g)
was added. The mixture was refluxed for 1-2 hours, concentrated
and cooled. The separated solid was collected by filtration,
washed, dried and recrystallised from methanol.
General Procedure.
5,7-Dimethyl-4-aryl-6-phenyl-4,5,6,7-tetrahydro-3-selena-1,2,5-
triazaindene (7) and 7-Methyl-4-aryl-6-phenyl-6,7-dihydro-4H-
5-thia-3-selena-1,2-diazaindene-5-oxide (8).
The semicarbazone 5 (5 mmoles) was dissolved in glacial
acetic acid (15 mL) and warmed gently with stirring. To this,
selenium dioxide (5 mmoles) was added portion wise during a
period of 30 minutes at 60-70 °C and the stirring was continued
for 4-5 hours. The reaction mixture was cooled and filtered onto
crushed ice. The separated solid was collected by filtration,
EXPERIMENTAL
Melting Points were determined on a Veego Sceintific PMP-
DM equipment and are uncorrected. Purity of the compounds

Jan-Feb 2003
Some Novel Annelated 1,2,3-Selena/Thiadiazoles and 2H-Diazaphospholes
153
REFERENCES and NOTES
Author to whom correspondence should be sent; e-mail:
washed with cold water, sodium bicarbonate solution and dried.
The residue was purified through column chromatography (Silica
gel; ethyl acetate-hexane, 1:3).
*
vkpuram2001@yahoo.com
General Procedure.
[1a] A. Shafiee, I. Lalazari, S. Yazdani and A. Pownoruz, J.
Pharma Sci., 62, 831 (1973); [b] I. Lalezari, A. Shafiee, and S.
Yazdani, J. Pharma Sci., 63, 628 (1974) and references cited therein;
[c] K. Sharma and S. P. Singh, Indian J. Chem., 31B, 396 (1992); [d] K.
S. Sharma, Kumari. Sarita and Kumari. Sharda, Indian J. Chem., 33B,
137 (1994); [e] C. Faria, M. Prizza, A. Gramba and G. Pifferri, Eur. J.
Med. Chem-Chim Ther., 14, 27 (1979); [f] G. Prota and R. H.
Thomson, Endevour, 35, 32 (1976).
[2a] D. Bhaskar Reddy, A. Somasekhar Reddy and V.
Padmavathi, J. Chem. Research (S), 784 (1998); [b] D. Bhaskar Reddy,
M. V. Ramana Reddy and V. Padmavathi, Indian J. Chem., 36B, 923
(1997); [c] V. Padmavathi, T. V. Ramana Reddy, A. Balaiah, K.
Audisesha Reddy and D. Bhaskar Reddy, Phosphorous, sulfur and sili-
cone, (In press)
5,7-Dimethyl-4-aryl-6-phenyl-4,5,6,7-tetrahydro-3-thia-1,2,5-
triazaindene (9) and 7-Methyl-4-aryl-6-phenyl-6,7-dihydro-4H-
3,5-dithia-1,2-diazaindene-5-oxide (10).
To a well cooled solution of semicarbazone 5 (5 mmoles) in
dichloromethane (20 mL), an excess of thionyl chloride (3 mL)
was added in portions while stirring and the mixture was allowed
to attain room temperature. After stirring for 2-3 hours, the excess
reagent was decomposed with cold saturated sodium carbonate
solution. The organic layer was separated, washed with water and
dried (anhydrous sodium sulfate). Evaporation of the solvent in
vacuo resulted a residue, which was subjected to column chro-
matography (silica gel) with ethyl acetate-hexane (1:2) as eluents.
[3] D. Bhaskar Reddy, A. Somasekhar Reddy and V.
Padmavathi, Synth. Commun., 31, 29 (2001) and references cited
therein.
General Procedure.
5,7-Dimethyl-4-aryl-2,6-diphenyl-4,5,6,7-tetrahydro-2H-1,2,5-
triaza-3-phosphaindene (11) and 7-Methyl-4-aryl-2,6-diphenyl-
2,4,6,7-tetrahydro-5-thia-2H-1,2-diaza-3-phosphaindene-5-
oxide (12).
[4] A. Selvaraj, S. Maragatha Sundaram, S. Perumal and N.
Arumugam, Indian J. Chem., 26B, 1104 (1987).
[5a] K. Ramalingam, K. D. Berlin, R. A. Loghri, Dickvan der
Halum and N. Satyamurthy J. Org. Chem., 44, 477 (1979); [b] D.
Bhaskar Reddy, A. Somasekhar Reddy and N. Subba Reddy, Indian J.
Chem., 38B, 1342 (1999).
[6a] R. Harville and S. F. Reed, Jr., J. Org. Chem., 33, 3976
(1968); [b] M. Haake, H. Gebbing and H. Benack, Synthesis, 97 (1979).
[7] C. R. Johnson and D. McCants, Jr., J. Am. Chem. Soc., 87,
1109 (1965).
[8] K. Pandiarajan, R. Sekar, R. Anantharaman and T.
Chellathurai, Indian J. Chem., 38B, 490 (1991).
To a stirred solution of phosphorous trichloride (15 mmoles)
and dry diethyl ether (20 mL) under nitrogen atmosphere main-
tained at –5 to –10 °C, phenyl hydrazone 6 ( 5 mmoles) in dry
ether (10 mL) was added drop wise. To this, triethylamine (20
mmoles) was added and stirring was continued for 3-4 hours.
The ethereal layer was separated, washed with sodium bicarbon-
ate solution, water and dried (anhydrous sodium sulfate). The
ether was removed under reduced pressure and the resultant
residue was purified by filtration through a column of silica gel
using ethyl acetate-hexane (1:2) as eluent to furnish 11 or 12.
[9] D. Nasipuri, Stereochemistry of Organic Compounds, Wiley
Eastern Limited, New Delhi, (1992), pp293-297.
[10] V. Baliah and T. Chellathurai, Indian J. Chem., 9, 424
(1971).
[11] I. Lalezari and A. Shafiee, Tet. Lett., 58, 5105 (1969).
[12] C. D. Hurd and R. I. Mori, J. Am. Chem. Soc., 77, 5359
(1955).
[13] J. Luber and A. Schmidpeter, Angew. Chem. Int. Ed. Engl.,
15(2), 111 (1976).
Acknowledgements.
One of the authors (TVRR) is thankful to Sri. R. N.
Bhattacharya, GM/SPROB and Sri. S. K. Athithan, DD/SPROB,
SHAR Centre for grant of permission and providing facilities to
conduct research and another author (DBR) is thankful to UGC,
New Delhi for the award of Emeritus Fellowship.
[14] C. R. Noller and V. Balaiah, J. Am. Chem. Soc., 70, 3853
(1948).