Facile synthesis and stracture of novel 2,5-disubstituted 1,3,4-selenadiazoles

Article abstract of DOI:10.1002/ejoc.200900013

The reaction of hydrazide with carbony] chloride in the presence of sodium carbonates leads to the corresponding 1,2- diacylhydrazines [1a-t, R ¹C(O)NHNHC(O)R², R¹ = aryl, R² = aryl or alkyl] in moderate to excellent yield (57-90%). The latter reacts with 2,4-diphenyl-l,3-diselenadiphosphetane- 2,4-diselenide (Woollins' reagent, WR) in refluxing toluene to give a series of new 2,5-disubstituted 1,3,4-selenadiazoles (2a-t, 51-99% yield). All compounds were characterized spectroscopically and six compounds were characterized crystalloqraphically. Wiley-VCH Verlag GmbH & Co. KGaA.

Full text of DOI:10.1002/ejoc.200900013

FULL PAPER
DOI: 10.1002/ejoc.200900013
Facile Synthesis and Structure of Novel 2,5-Disubstituted 1,3,4-Selenadiazoles
Guoxiong Hua,[a] Yang Li,[a] Amy L. Fuller,[a] Alexandra M. Z. Slawin,[a] and
J. Derek Woollins*[a]
Keywords: Selenium / Organoselenium chemistry / 1,3,4-Selenadiazoles / Woollins’ reagent
The reaction of hydrazide with carbonyl chloride in the pres-
ence of sodium carbonates leads to the corresponding 1,2-
diacylhydrazines [1a–t, R1C(O)NHNHC(O)R2, R1 = aryl, R2 =
aryl or alkyl] in moderate to excellent yield (57–90%). The
latter reacts with 2,4-diphenyl-1,3-diselenadiphosphetane-
2,4-diselenide (Woollins’ reagent, WR) in refluxing toluene to
give a series of new 2,5-disubstituted 1,3,4-selenadiazoles
(2a–t, 51–99% yield). All compounds were characterized
spectroscopically and six compounds were characterized
crystallographically.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2009)
Introduction
for various thionation reactions.[11] Compared with other
selenation reagents WR has broad utility and is useful in
the synthesis of a wide range of selenium-containing com-
pounds. These compounds include large P/Se molecular ag-
gregates or metal complexes by nucleophilic ring-opening
reactions with alkali-metal thiolates,[12] selenoamides and
selenoaldehydes by simple oxygen/selenium exchange or re-
action with ArCN followed by hydrolysis and a wide variety
of P–Se heterocycles.[13] Here, we report the synthesis and
characterization of a series of novel 2,5-disubstituted 1,3,4-
selenadiazoles from the selenation of the corresponding 1,2-
diacylhydrazine with WR. To the best of our knowledge,
this is the first report of the systematic synthesis of 2,5-
disubstituted 1,3,4-selenadiazoles. Furthermore, six exam-
ples, representing the first examples of this class have been
structurally characterised.
The synthesis of the organoselenium compound diethyl
selenide was first reported in 1836.[1] It was not until the
1970s, where the use of diethyl selenide in several new reac-
tions created a variety of novel structures with unusual
properties, that these compounds began to attract more ge-
neral interest. The interest in using organoselenium hetero-
cycles as potential pharmaceuticals and new materials, as
well as reagents and catalysts expanded rapidly during last
three decades.[2] For example, 1,3,4-selenadiazoles have
been studied because of their potential activities as antibac-
terial, analgesic, antitumor, anticonvulsant, and antiinflam-
matory drugs, pesticides and fungicides.[3] Furthermore,
some of them have been used as thermotropic liquid crys-
tals, corrosion and oxidation inhibitors, or as dyes or metal
ion complexation reagents.[4] However, little is known about
the 2,5-disubstituted 1,3,4-selenadiazoles.[5] Several meth-
ods have been reported for their preparation, which include
a ring-closure reaction of selenobenzamides with hydrazine
hydrate,[6] reacting dimethylformamide azine with hydrogen
selenide,[7] treatment of 1,2-diacetylhydrazine with phos-
phorus pentaselenide,[8] reaction of isoselenocyanates with
selenosemicarbazides[9] or a carboxylic acid with seleno-
semicarbazide and phosphoryl chloride.[10] However, the ex-
amples of these compounds in the literature are limited due
to either lack of starting materials or very low yield.
Results and Discussion
Preparation of 1,2-diacylhydrazines 1a–t was very
straightforward using
a modification of a literature
method.[14] Reaction between hydrazides and carbonyl chlo-
rides in the presence of sodium carbonate leads to the cor-
responding 1a–t in good to excellent yields (57–90%,
Scheme 1 and Table 1). Even though most of the 1,2-di-
acylhydrazines had been previously synthesized; our modi-
fication of the literature preparation improved the yield and
synthetic efficiency of their preparation. 1,2-Diacylhydraz-
2,4-Diphenyl-1,3-diselenadiphosphetane 2,4-diselenide
[PhP(Se)(µ-Se)]2, known as Woollins’ reagent (WR), is the
selenium counterpart of the well-known Lawesson’s reagent
[p-MeOC6H4P(S)(µ-S)]2 (LR). LR has been used extensively
1
ines, 1a–t, were characterised by IR, H NMR, 13C NMR
and MS data. The Infrared spectrum of these compounds
show a strong absorption in the region of 1599–1637 cm–1
and the 13C NMR spectra display a characteristic peak in
the region of 139.0–171.1 ppm, both are assignable to char-
acteristic carbonyl groups, confirming the formation of 1,2-
diacylhydrazines. There is also a characteristic 1H NMR
[a] School of Chemistry, University of St Andrews,
Fife, Scotland, KY16 9ST, UK
Fax: +44-1334-463384
E-mail: jdw3@st-and.ac.uk
1612
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2009, 1612–1618

Novel 2,5-Disubstituted 1,3,4-Selenadiazoles
resonance from the NHNH group in the region of 9.80– tory drugs, along with activity as pesticides and fungi-
10.69 ppm. Finally, the compounds display clear molecular cides,[17,19] as well as other applications.[4a–4c,20] The most
ion peaks in their mass spectra.
popular method for the synthesis of this class of com-
pounds involves the cyclization and dehydration of thiohyd-
razides or other substrates with an S–C–N–N–C–S moi-
ety.[4a,15,16] This is typically done via thionation of 1,2-di-
acylhydrazines with Lawesson’s reagent, followed by spon-
taneous cyclization and dehydrosulfurization.[14c] Herein,
we adopted a similar approach, that is, reacting 1,2-di-
acylhydrazines, 1a–t, with WR to afford a series of 2,5-di-
substituted 1,3,4-selenadiazoles, 2a–t, in moderate to excel-
lent yield (51–99%, Scheme 1 and Table 1). It should be
noted in particular that reaction of WR with 1,2-diacylhyd-
razines bearing diaryl groups (R1, R2 = Aryl) is very fast
and high yield (75–99%), while with the 1,2-diacylhydraz-
ines bearing one aryl group and one pyridine group (R1 =
Aryl; R2 = Pyr) is slow with relatively low yield (51 and
58% for compounds 2b and 2c, respectively), This is most
likely due to the presence of the electron-withdrawing pyr-
idine group. 2 are stable in air and moisture for several
months and are soluble in common organic solvents.
The characterisation of 2a–t is based on elemental analy-
ses, 1H, 13C and 77Se NMR, IR spectroscopy and mass
spectrometry. The elemental analyses for all of these new
compounds were satisfactory. All of compounds showed the
anticipated molecular ion peaks [M]+, [M – H]+, [M + H]+
or [M + Na]+ in their mass spectra. The ν(C=N) vibrations
are observed in the range of 1418–1495 cm–1, comparable
with related hetercycles.[21] The absence of ν (1599–
1637 cm–1 for C=O) and the presence of the typical 13C
NMR signals in the range of 133.1–174.9 ppm for C=N
double bond and 77Se NMR signals in the range of 683.01–
714.61 ppm indicate the formation of the five-membered
ring systems, 2a–t.
Scheme 1. Synthesis of 1,2-diacylhydrazines 1a–t and 2,5-disubsti-
tuted 1,3,4-selenadiazoles 2a–t.
Table 1. Synthesis of 1,2-diacylhydrazines 1a–t and 2,5-disubsti-
tuted 1,3,4-selenadiazoles 2a–t.
R1
R2
1
Yield
(%)
2
Yield
(%)
C6H5
4-BrC6H4
C6H5
4-MeOC6H4 pyridin-3-yl
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
4-BrC6H4
pyridin-3-yl
1a
1b
1c
1d
1e
1f
1g
1h
1i
1j
1k
1l
1m
1n
1p
1r
1s
1t
61
65
77
82
63
67
69
81
70
90
81
65
63
69
77
68
57
81
2a
2b
2c
2d
2e
2f
2g
2h
2i
2j
2k
2l
2m
2n
2p
2r
2s
2t
98
75
51
58
90
97
95
91
97
99
82
90
96
90
86
83
79
75
4-MeC6H4
4-ClC6H4
4-BrC6H4
4-FC6H4
thiophen-2-yl
C2H5O
furan-2-yl
furan-2-yl
furan-2-yl
C6H5
C6H5
4-MeC6H4
4-BrC6H4
4-MeOC6H4 4-MeC6H4
4-MeOC6H4 C6H5
4-MeC6H4
4-MeC6H4
4-MeC6H4
Surprisingly, to date, there have been no crystal struc-
tures of 1,3,4-selenadiazole yet reported. Here we report the
structures of six examples 2b, 2h, 2k, 2m, 2p and 2s (Figure
1). Colourless block crystals of these compounds were ob-
tained for X-ray analysis via slow evaporation of a dichloro-
methane solution into hexane. Details of the selected inter-
atomic distances and angles are given in Table 2. Unfortu-
4-ClC6H4
4-FC6H4
4-BrC6H4
2,5-Disubstituted 1,3,4-thiadiazoles, the sulfur counter- nately, the data for 2g could not be well-refined though the
part of 2,5-disubstituted 1,3,4-selenadiazoles, have been ex- structure is closely similar to the other six described here.[22]
amined as potential antibacterial,[15] antiviral,[16] analge- The overall molecular structures of these compounds are
sic,[17] antitumor,[18] anticonvulsant,[15] and antiinflamma- very similar in geometry. The C2N2Se rings are approxi-
Table 2. Selected interatomic distances (Å) and angles (°) for 2b, 2h, 2k, 2m, 2p and 2s.
2b
2h
2k
2m
2p
2s
Se(1)–C(1)
Se(1)–C(2)
C(2)–N(2)
N(2)–N(1)
1.885(10)
1.884(10)
1.295(13)
1.381(12)
1.276(12)
81.9(4)
113.9(7)
114.5(8)
115.6(8)
114.0(8)
1.891(7)
1.884(7)
1.296(9)
1.363(8)
1.307(9)
82.0(3)
114.7(5)
114.1(6)
116.5(6)
112.6(5)
1.861(5)
1.887(5)
1.302(7)
1.374(7)
1.302(7)
81.9(2)
113.7(4)
115.1(4)
114.1(5)
115.2(4)
1.869(9)
1.894(8)
1.299(12)
1.380(10)
1.295(12)
82.2(4)
112.9(6)
115.8(8)
114.0(8)
115.0(7)
1.880(3)
1.877(3)
1.298(4)
1.373(4)
1.297(4)
82.22(15)
113.8(3)
115.1(3)
115.0(3)
113.9(3)
1.902(5)
1.890(5)
1.301(6)
1.379(6)
1.294(6)
82.7(2)
113.5(4)
114.7(4)
116.8(4)
112.2(4)
C(1)–N(1)
C(1)–Se(1)–C(2)
Se(1)–C(2)–N(2)
C(2)–N(2)–N(1)
N(2)–N(1)–C(1)
N(1)–C(1)–Se(1)
Eur. J. Org. Chem. 2009, 1612–1618
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1613

G. Hua, Y. Li, A. L. Fuller, A. M. Z. Slawin, J. D. Woollins
FULL PAPER
mately co-planar with the two aromatic substituents. This
can be readily illustrated through a comparison of the tor-
sion angles to the substituents which are all close to 180°
[range 176.1(7)–180.0(8)°]. The C–Se bond lengths for all
six compounds (ca. 1.87–1.89 Å) are similar to that of 2,5-
diarylselenophenes (ca. 1.86–1.89 Å).[23] The distances in 2
are slightly shorter than those found in related structures
containing single C–Se bonds (ca. 1.92–1.94 Å),[24] indicat-
ing that some slight delocalisation in 2. However, the C–
Se–C angles ranging between 81.9(2)–82.7(2)° in 2b, 2h, 2k,
2m, 2p and 2s are considerably smaller than that [ca.
87.7(7)–88.7(10)°] in 2,5-diarylselenophenes.[24]
Conclusions
In summary, a highly efficient route for the preparation
of a wide variety of 1,2-diacylhydrazines has been devel-
oped. The selenation of 1,2-diacylhydrazines using Wool-
lins’ reagent, 2,4-diphenyl-1,3-diselenadiphosphetane-2,4-
diselenide, provides a general and systemic approach to 2,5-
disubstituted 1,3,4-selenadiazoles. This method allows 2,5-
disubstituted 1,3,4-selenadiazoles to be easily available for
further investigations into their chemistry and biological
properties.
Experimental Section
General: Unless otherwise stated, all reactions were carried out un-
der on oxygen free nitrogen atmosphere using pre-dried solvents
and standard Schlenk techniques, subsequent chromatographic and
work up procedures were performed in air. Solvents were dried,
purified, and stored according to common procedures.
1H (270 MHz), 13C (67.9 MHz), 31P{1H} (109 MHz) and 77Se-{1H}
(51.4 MHz referenced to external Me2Se) NMR spectra were re-
corded at 25 °C (unless stated otherwise) on a JEOL GSX 270. IR
spectra were recorded as KBr pellets in the range of 4000–250 cm–1
on a Perkin–Elmer 2000 FTIR/Raman spectrometer. Microanalysis
was performed by the University of St-Andrews microanalysis ser-
vice. Mass spectrometry was performed by the University of St An-
drews Mass Spectrometry Service. X-ray crystal data as Table 3 for
compounds 2b, 2g, 2h, 2k, 2m, 2p and 2s was collected at 93 K
by using a Rigaku MM007 High brilliance RA generator/confocal
optics and Mercury CCD system. Intensities were corrected for
Lorentz-polarisation and for absorption. The structures were
solved by direct methods. Hydrogen atoms bound to carbon were
idealised. Structural refinements were obtained with full-matrix
least-squares based on F2 by using SHELXTL.
CCDC-711573 (for 2b), -711574 (for 2h), -711575 (for 2k), -711576
(for 2m), -711577 (for 2p), -711578 (for 2s), contain the supplemen-
tary crystallographic data for this paper. These data can be ob-
tained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
General Procedure for Synthesis of 1,2-Diacylhydrazines 1a–t: A
suspension of carbonyl hydrazide (10.0 mmol) and anhydrous so-
dium carbonate (1.02 g, 10.0 mmol) in dry tetrahydrofuran (60 mL)
and water (60 mL) was added to a stirring solution of the corre-
sponding carbonyl chloride (11.0 mmol) in 30 mL of tetra-
hydrofuran at 0 °C. The mixture was stirred at 0 °C for 1 h, and at
room temperature for 4 h. A massive precipitation was observed.
The product was harvested by filtration and washed three times
with tetrahydrofuran and ethyl ether, then finally dried in vacuo.
NЈ-Benzoylbenzohydrazide (1a): A white solid (61%, 1.45 g); m.p.
236–238 °C. Selected IR (KBr): ν = 3201 (s), 3001 (s), 1670 (m),
˜
1
1633 (vs), 1579 (s), 1537 (s), 1487 (s), 1287 (s), 687 (m) cm–1. H
NMR ([D6]DMSO): 10.53 (s, 2 H, NH), 7.94 (m, 4 H, H2, H6
ArH), 7.55 (m, 6 H, H3, H4, H5 ArH) . 13C NMR ([D6]DMSO):
δ = 166.3 (C=O), 133.3, 132.4, 129.1, 128.0 ppm. MS (CI): m/z =
241 [M + H]+.
4-Bromo-NЈ-(4-chlorobenzoyl)benzohydrazide (1b): A white solid
(65%, 2.30 g); m.p. 302–303 °C. Selected IR (KBr): ν = 3187 (s),
˜
3017 (w), 1601 (vs), 1561 (s), 1461 (s), 1264 (m), 1090 (m), 1010
1
(m), 848 (m), 742 (m), 659 (m) cm–1. H NMR ([D6]DMSO): δ =
Figure 1. X-ray crystal structures of 2b (A), 2h (B), 2k (C), 2m (D),
2p (E) and 2s (F).
10.66 (s, 2 H, NH), 7.95 [d, J(H,H) = 8.5 Hz, 2 H, ArH], 7.87 [d,
1614
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© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2009, 1612–1618

Novel 2,5-Disubstituted 1,3,4-Selenadiazoles
Table 3. Details of the X-ray data collections and refinements for 2b, 2h, 2k, 2m, 2p and 2s.
2b
2h
2k
2m
2p
2s
Formula
M
Crystal system
Space group
a [Å]
b [Å]
c [Å]
C14H8Br2N2Se
443.00
monoclinic
P21/c
15.421(6)
14.353(5)
6.121(2)
101.091(10)
1329.4(8)
4
C14H9FN2Se
303.19
monoclinic
P21/c
13.160(6)
5.489(3)
16.177(8)
99.108(12)
1153.8(10)
4
C12H8N2OSe
275.16
orthorhombic
P212121
7.217(3)
13.857(5)
10.474(3)
90
C12H7BrN2OSe
354.07
monoclinic
P21/c
6.112(3)
21.886(9)
8.871(4)
103.712(10)
1152.8(9)
4
C15H12N2OSe
315.23
orthorhombic
Pbca
14.222(6)
6.056(3)
29.774(15)
90
C15H11FN2Se
317.22
monoclinic
P21/c
14.888(8)
14.385(7)
6.002(3)
97.699(13)
1273.9(11)
4
β
U/A3
1047.4(6)
4
3.56
2564(2)
8
2.92
Z
µ [mm]–1
8.82
3.25
6.71
2.95
Reflections collected
Independent reflections
Rint
8630
2678
0.120
0.094
7127
2266
0.103
0.075
7030
2152
0.101
0.048
7733
2277
0.217
0.098
15423
2582
0.049
0.045
8122
2610
0.161
0.086
R(F2)Ͼ2σ (F2)
wR2 [IϾ2σ(I)]
0.273
0.252
0.114
0.308
0.088
0.227
1
J(H,H) = 8.5 Hz, 2 H, ArH], 7.75 [d, J(H,H) = 8.5 Hz, 2 H, ArH],
1600 (vs), 1576 (s), 1561 (s), 1461 (s), 1264 (s), 706 (m) cm–1. H
7.62 [d, J(H,H) = 8.5 Hz, 2 H, ArH] ppm. 13C NMR ([D6]DMSO): NMR ([D6]DMSO): δ = 10.58 (s, 2 H, NH), 7.91 (m, 3 H, ArH),
δ = 165.5 (C=O), 165.4 (C=O), 137.4, 132.2, 132.1, 131.8, 130.1,
7.77 (m, 2 H, ArH), 7.55 (m, 4 H, ArH) ppm. 13C NMR ([D6]-
130.0, 129.3, 126.3 ppm. MS (ES+): m/z = 377 [M + Na]+. MS DMSO): δ = 166.4 (C=O), 165.6 (C=O), 133.0, 132.5, 132.2, 130.1,
(ES–): m/z = 353 [M – H]+.
129.9, 129.1, 128.0, 126.3 ppm. MS (CI): = 319 [M + H]+.
NЈ-Benzoyl-4-fluorobenzohydrazide (1h): white solid (81%,
2.06 g); m.p. 228–230 °C. Selected IR (KBr): ν = 3209 (s), 3011 (s),
NЈ-Benzoylnicotinohydrazide (1c): A white solid (77%, 1.85 g); m.p.
A
232–234 °C. Selected IR (KBr): ν = 3201 (m), 3003 (m), 1631 (s),
˜
˜
1537 (s), 1295 (s), 874 (m), 698 (s) cm–1. H NMR ([D6]DMSO): δ 1674 (s), 1635 (vs), 1605 (s), 1538 (s), 1504 (s), 1283 (s), 1240 (s),
1
= 10.69 (s, 2 H, NH), 9.09 (s, 1 H, PyH), 8.80 (d, 1 H, PyH), 8.29
(d, 1 H, PyH), 7.94 (m, 2 H, ArH), 7.57 (m, 4 H, PyH and ArH)
1160 (m), 849 (m), 688 (m), 594 (m), 541 (m) cm–1. 1H NMR ([D6]-
DMSO): δ = 10.57 (s, 2 H, NH), 8.02 (m, 2 H, ArH), 7.95 (m, 2
ppm. 13C NMR ([D6]DMSO): δ = 166.3 (C=O), 165.0 (C=O), H, ArH), 7.56 (m, 3 H, ArH), 7.38 (m, 2 H, ArH) ppm. 13C NMR
153.1, 149.0, 135.8, 133.0, 132.5, 129.1, 128.9, 128.0, 124.3 ppm.
([D6]DMSO): δ = 166.4 (C=O), 165.4 (C=O), 163.0, 133.1, 132.5,
139.7, 129.1, 128.0, 116.3, 116.0 ppm. MS (ES+): m/z = 281 [M +
Na]+. MS (ES–): m/z = 257 [M – H]+.
MS (CI): m/z = 242 [M + H]+.
NЈ-(4-Methoxybenzoyl)nicotinohydrazide (1d): A white solid (82%,
2.21 g); m.p. 126–128 °C. Selected IR (KBr): ν = 3203 (m), 3003
NЈ-Benzoylthiophen-2-carbohydrazide (1i): A white solid (70%,
˜
(m), 1632 (s), 1605 (s), 1503 (s), 1258 (s), 1175 (m), 1026 (m), 846 1.72 g); m.p. 102–104 °C. Selected IR (KBr): ν = 3210 (m), 3020
˜
(w), 704 (w) cm–1. 1H NMR ([D6]DMSO): δ = 10.66 (s, 2 H, NH),
9.10 (s, 1 H, PyH), 8.79 (d, 1 H, PyH), 8.30 (d, 1 H, PyH), 7.93
(m, 2 H, ArH), 7.58 (m, 1 H, PyH), 7.07 (m, 2 H, ArH), 3.84 (s, 3
(m), 1715 (m), 1652 (s), 1536 (s), 1270 (s), 709 (m) cm–1. 1H NMR
([D6]DMSO): δ = 9.80 (s, 2 H, NH), 9.81 (s, 2 H, NH), 9.00 (m, 3
H), 7.72 (m, 3 H), 7.13 (m, 2 H) ppm. 13C NMR ([D6]DMSO): δ
H, OCH3) ppm. 13C NMR ([D6]DMSO): δ = 165.9 (C=O), 165.1 = 161.7 (C=O), 139.0 (C=O), 130.9, 128.5, 128.0 ppm. MS (CI):
(C=O), 153.1, 149.0, 135.8, 129.9, 128.9, 125.1, 124.3, 114.4, 114.0,
m/z = 247 [M + H]+.
56.0 ppm. MS (CI): m/z = 272 [M + H]+.
Ethyl 2-Benzoylhydrazinecarboxylate (1j): A white paste (90%,
NЈ-Benzoyl-4-methylbenzohydrazide (1e):
A
white solid (63%,
1.85 g); Selected IR (KBr): ν = 3208 (m), 3021 (m), 1711 (s), 1650
˜
1.58 g); m.p. 219–221 °C. Selected IR (KBr): ν = 3202 (s), 3007 (s), (s), 1530 (m), 1326 (m), 1267 (s), 707 (s) cm–1. 1H NMR ([D6]-
˜
1631 (vs), 1578 (m), 1539 (s), 1489 (m), 1284 (s), 691 (m) cm–1. H
NMR ([D6]DMSO): δ = 10.45 (s, 2 H, NH), 7.93 [d, J(H,H) =
7.7 Hz, 2 H, ArH], 7.84 [d, J(H,H) = 7.4 Hz, 2 H, ArH], 7.55 (m,
DMSO): δ = 8.81 (s, 2 H, NH), 8.10 (m, 2 H, ArH), 7.80 (m, 1 H,
ArH), 7.48 (m, 2 H, ArH), 4.14 [q, J(H,H) = 7.2 Hz, 2 H, OCH2],
1.23 [t, J(H,H) = 7.2 Hz, 3 H, CH3] ppm. 13C NMR ([D6]DMSO):
1
3 H, ArH), 7.32 [d, J(H,H) = 7.4 Hz, 2 H, ArH], 2.38 (s, 3 H, CH3) δ = 171.1 (C=O), 167.3 (C=O), 133.7, 130.1, 127.4, 62.5, 14.2 ppm.
ppm. 13C NMR ([D6]DMSO): δ = 166.4 (C=O), 166.2 (C=O), MS (CI): m/z = 209 [M + H]+.
142.4, 133.3, 132.4, 130.4, 129.6, 129.1, 128.0, 21.6 ppm. MS (CI):
NЈ-Benzoylfuran-2-carbohydrazide (1k):
1.85 g); m.p. 208–210 °C. Selected IR (KBr): ν = 3198 (s), 1672
A white solid (81%,
m/z = 255 [M + H]+.
˜
NЈ-Benzoyl-4-chlorobenzohydrazide (1f):
A
white solid (67%,
(m), 1634 (vs), 1592 (m), 1580 (m), 1525 (m), 1471 (m), 1291 (s),
1.96 g); m.p. 224–226 °C. Selected IR (KBr): ν = 3195 (s), 3010 (w),
1221 (m), 1159 (m), 1010 (m), 846 (m), 754 (m), 703 (m), 689 (m),
˜
1
2843 (w), 1599 (vs), 1564 (s), 1498 (m), 1461 (s), 1266 (m), 1089 594 (m), 540 (m) cm–1. H NMR ([D6]DMSO): δ = 10.46 (s, 2 H,
(m), 1010 (m), 849 (m), 710 (m), 687 (m), 647 (m), 454 (m) cm–1. NH), 7.95 (m, 3 H, ArH), 7.55 (m, 3 H, ArH&FurH), 7.28 (d, 1
1H NMR ([D6]DMSO): δ = 10.60 (s, 2 H, NH), 7.94 (m, 5 H, H, FurH), 6.69 (t, 1 H, FurH) ppm. 13C NMR ([D6]DMSO): δ =
ArH), 7.55 (m, 4 H, ArH) ppm. 13C NMR ([D6]DMSO): δ = 166.4
166.4 (C=O), 157.9 (C=O), 146.9, 146.4, 133.0, 132.5, 129.1, 128.0,
(C=O), 165.4 (C=O), 137.3, 133.1, 132.5, 131.9, 130.0, 129.2, 129.1, 115.2, 112.5 ppm. MS (ES+): m/z = 253 [M + Na]+. MS (ES–): m/z
128.0 ppm. MS (ES+): m/z = 297 [M + Na]+. MS (ES–): m/z = 273
[M – H]+.
= 229 [M – H]+.
NЈ-(4-Methylbenzoyl)furan-2-carbohydrazide (1l): A white solid
NЈ-Benzoyl-4-bromobenzohydrazide (1g):
A
white solid (69%,
(65%, 1.57 g); m.p. 225–227 °C. Selected IR (KBr): ν = 3173 (m),
˜
2.18 g); m.p. 207–209 °C. Selected IR (KBr): ν = 3192 (s), 3009 (w),
3011 (m), 1673 (m), 1631 (vs), 1592 (m), 1527 (m), 1504 (m), 1471
˜
Eur. J. Org. Chem. 2009, 1612–1618
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1615

G. Hua, Y. Li, A. L. Fuller, A. M. Z. Slawin, J. D. Woollins
(m), 1286, 1217 (m), 1186 (m), 1120 (m), 1020 (m), 851 (m), 746 2 H, ArH], 7.05 [d, J(H,H) = 7.7 Hz, 2 H, ArH], 3.83 (s, 3 H,
FULL PAPER
1
(s), 595 (s), 540 (m) cm–1. H NMR ([D6]DMSO): δ = 10.37 (s, 2
OCH3) ppm. 13C NMR ([D6]DMSO): δ = 165.9 (C=O), 165.6
H, NH), 7.91 (d, 1 H, FurH), 7.81 [d, J(H,H) = 6.6 Hz, 2 H, ArH], (C=O), 162.6, 132.2, 130.1, 130.0, 126.2, 125.2, 114.3, 56.0 ppm.
7.31 [d, J(H,H) = 6.6 Hz, 2 H, ArH], 7.26 (d, 1 H, FurH), 6.68 (m,
1 H, FurH), 2.37 (s, 3 H, CH3) ppm. 13C NMR ([D6]DMSO): δ =
166.3 (C=O), 158.0 (C=O), 146.9, 146.3, 142.5, 130.2, 129.6, 128.1,
115.1, 112.4, 21.6 ppm. MS (ES+): m/z (%) = 267 [M + Na]+.
MS (ES+): m/z = 371 [M + Na]+.
General Procedure for the Synthesis of 2,5-Disubstituted 1,3,4-Selena-
diazoles 2a-t: A mixture of 1,2-diacylhydrazines (1.0 mmol) and
Woollins’ reagent (0.54 g, 1.0 mmol) in 20 mL of dry toluene was
refluxed for 7 h. The red suspension disappeared and a brown sus-
pension was formed along with some grey elemental selenium. Af-
ter cooling to room temperature the mixture was dried in vacuo to
remove toluene. The residue was then dissolved in dichloromethane
and purified by silica gel (1:5 ethyl acetate/dichloromethane as elu-
ent) to give the corresponding target product.
NЈ-(4-Bromobenzoyl)furan-2-carbohydrazide (1m): A white solid
(63%, 1.95 g); m.p. 191–193 °C. Selected IR (KBr): ν = 3167 (w),
˜
3004 (w), 1637 (vs), 1592 (s), 1520 (m), 1483 (m), 1289 (m), 1010
1
(m), 840 (m), 747 (m), 594 (m) cm–1. H NMR ([D6]DMSO): δ =
10.57 (s, 2 H, NH), 7.94 [d, J(H,H) = 10.2 Hz, 1 H, FurH], 7.85
[d, J(H,H) = 8.2 Hz, 2 H, ArH], 7.74 [d, J(H,H) = 8.2 Hz, 2 H,
ArH], 7.27 [d, J(H,H) = 10.2 Hz, 1 H, FurH], 6.69 (m, 1 H, FurH)
ppm. 13C NMR ([D6]DMSO): δ = 165.5 (C=O), 157.9 (C=O),
148.4, 146.4, 132.5, 132.2, 130.1, 126.3, 115.3, 112.5 ppm. MS
(ES+): m/z = 333 [M + Na]+. MS (ES–): m/z = 309 [M – H]+.
2,5-Diphenyl-1,3,4-selenadiazole (2a): A yellow solid (98%, 0.28 g);
m.p. 116–118 °C. Selected IR (KBr): ν = 3424 (s), 1438 (m), 1149
˜
(s), 933 (m), 691 (s), 543 (s) cm–1. 1H NMR (CD2Cl2): δ = 7.95 (m,
4 H, ArH), 7.50 (m, 6 H, ArH) ppm. 13C NMR (CD2Cl2): δ = 174.9
(C=N), 1431.2, 129.3, 128.7, 126.9 ppm. 77Se NMR (CD2Cl2): δ
= 687.13 ppm. MS (CI): m/z = 287 [M + H]+. C14H10N2Se (285.11):
calcd. C 58.98, H 3.54, N 9.83; found C 59.30, H 3.85, N 9.79.
4-Methoxy-NЈ-(4-methylbenzoyl)benzohydrazide (1n): A white solid
(69%, 1.94 g); m.p. 214–216 °C. Selected IR (KBr): ν = 3214 (s),
˜
3010 (w), 2844 (w), 1599 (vs), 1561 (m), 1512 (m), 1469 (m), 1440
(m), 1255 (s), 1177 (m), 1028 (m), 840 (m), 743 (m), 598 (m) cm–1.
1H NMR ([D6]DMSO): δ = 10.35 (s, 2 H, NH), 7.92 [d, J(H,H) =
8.5 Hz, 2 H, ArH], 7.83 [d, J(H,H) = 8.5 Hz, 2 H, ArH], 7.31 [d,
J(H,H) = 8.5 Hz, 2 H, ArH], 7.05 [d, J(H,H) = 8.5 Hz, 2 H, ArH],
3.85 (s, 3 H, OCH3), 2.37 (s, 3 H, CH3) ppm. 13C NMR ([D6]-
DMSO): δ = 166.4 (C=O), 165.9 (C=O), 162.6, 142.4, 130.4, 129.9,
129.6, 128.0, 125.3, 114.3, 56.0, 21.6 ppm. MS (ES+): m/z = 307 [M
+ Na]+.
2,5-Bis(4-bromophenyl)-1,3,4-selenadiazole (2b):
(75%, 0.33 g); m.p. 210 °C (dec.). Selected IR (KBr): ν = 3424 (w),
A yellow solid
˜
2921 (w), 1602 (s), 1544 (m), 1477 (vs), 1397 (m), 1266 (w), 1090
(s), 1072 (s), 1009 (s), 838 (s), 737 (s), 520 (m) cm–1. 1H NMR
(CD2Cl2): δ = 8.06 [d, J(H,H) = 8.5 Hz, 2 H, ArH], 7.98 [d, J(H,H)
= 8.5 Hz, 2 H, ArH], 7.67 [d, J(H,H) = 8.5 Hz, 2 H, ArH], 7.51 [d,
J(H,H) = 8.5 Hz, 2 H, ArH] ppm. 13C NMR (CD2Cl2): δ = 164.1
(C=N), 151.7 (C=N), 138.3, 132.6, 130.1, 129.9, 129.6, 128.4, 128.3,
126.7, 122.7 ppm. 77Se NMR (CD2Cl2): δ = 690.60 ppm. MS (CI):
m/z = 443 [M + H]+. C14H8Br2N2Se (442.91): calcd. C 37.96, H
1.82, N 6.32; found C 37.66, H 1.91, N 6.08.
NЈ-Benzoyl-4-methoxybenzohydrazide (1p): A white solid (77%,
2.07 g); m.p. 188–190 °C. Selected IR (KBr): ν = 3206 (s), 3005 (s),
˜
1632 (s), 1607 (s), 1542 (m), 1505 (s), 1260 (s), 1175 (m), 1031 (m),
1
842 (m), 691 (m) cm–1. H NMR ([D6]DMSO): δ = 10.42 (s, 2 H,
2-Phenyl-5-(pyridine-3-yl)-1,3,4-selenadiazole (2c): A greenish yel-
low solid (51%, 0.15 g); m.p. 90–92 °C. Selected IR (KBr): ν = 3424
˜
NH), 7.92 (m, 4 H, ArH), 7.55 (m, 3 H, ArH), 7.07 (m, 2 H, ArH),
3.41 (s, 3 H, OCH3) ppm. 13C NMR ([D6]DMSO): δ = 166.5
(C=O), 165.9 (C=O), 133.3, 132.4, 130.0, 129.1, 128.0, 125.3, 114.3,
56.0 (OCH3) ppm. MS (CI): m/z = 271 [M + H]+.
(s), 1454 (m), 1435 (m), 1127 (m), 1055 (m), 761 (m), 690 (s), 532
1
(s) cm–1. H NMR (CD2Cl2): δ = 8.38 (s, 1 H, PyH), 8.13 (d, 1 H,
PyH), 7.93 (m, 3 H, PyH & ArH), 7.57 (m, 4 H, ArH) ppm. 13C
NMR (CD2Cl2): δ = 149.5 (C=N), 147.6 (C=N), 137.3, 131.6,
4-Chloro-NЈ-(4-methylbenzoyl)benzohydrazide (1r): A white solid
129.4, 128.9, 127.0, 124.9 ppm. 77Se NMR (CD2Cl2):
δ =
(68%, 1.95 g); m.p. 255–256 °C. Selected IR (KBr): ν = 3193 (s),
˜
698.88 ppm. MS (CI): m/z = 287 [M + H]+. C13H9N3Se (286.10):
3014 (w), 1599 (vs), 1563 (s), 1511 (m), 1463 (s), 1267 (m), 1225
(m), 1090 (m), 1012 (m), 850 (m), 741 (m), 663 (m), 603 (m), 462
calcd. C 54.56, H 3.17, N 14.68; found C 54.10, H 3.61, N 14.57.
2-(4-Methoxyphenyl)-5-(pyridine-3-yl)-1,3,4-selenadiazole (2d):
yellow solid (58%, 0.18 g); m.p. 98–100 °C. Selected IR (KBr): ν =
A
1
(m) cm–1. H NMR ([D6]DMSO): δ = 10.53 (s, 2 H, NH), 7.94 [d,
˜
J(H,H) = 7.7 Hz, 2 H, ArH], 7.74 [d, J(H,H) = 7.2 Hz, 2 H, ArH],
7.61 [d, J(H,H) = 7.2 Hz, 2 H, ArH], 7.33 [d, J(H,H) = 7.7 Hz, 2
H, ArH], 2.38 (s, 3 H, CH3) ppm. 13C NMR ([D6]DMSO): δ =
166.3 (C=O), 165.4 (C=O), 142.5, 137.3, 131.9, 130.2, 130.0, 129.6,
129.3, 128.1, 21.6 ppm. MS (ES+): m/z = 311 [M + Na]+. MS (ES–):
m/z = 287 [M – H]+.
3425 (m), 3049 (m), 1454 (m), 1434 (s), 1140 (m), 1081 (m), 958
(m), 761 (m), 690 (s), 534 (s) cm–1. 1H NMR (CD2Cl2): δ = 9.54
(s, 1 H, PyH), 9.01 (d, 1 H, PyH), 8.88 (d, 1 H, PyH), 8.01 (m, 3
H, PyH & ArH), 7.47 (m, 4 H, PyH & ArH), 3.86 (s, 3 H, OCH3)
ppm. 13C NMR (CD2Cl2): δ = 144.0 (C=N), 142.6 (C=N), 132.0,
129.4, 129.0, 128.4, 128.2, 127.9, 127.2, 55.8 ppm. 77Se NMR
(CD2Cl2): δ = 714.61 ppm. MS (CI): m/z = 318 [M + H]+.
C14H12N3OSe (317.14): calcd. C 53.18, H 3.51, N 13.29; found C
53.51, H 3.61, N 13.57.
4-Fluoro-NЈ-(4-methylbenzoyl)benzohydrazide (1s): A white solid
(57%, 1.55 g); m.p. 224–225 °C. Selected IR (KBr): ν = 3202 (m),
˜
3013 (w), 1605 (vs), 1584 (s), 1511 (m), 1461 (s), 1267 (m), 1225
1
(m), 1155 (m), 851 (m), 742 (m), 661 (m), 600 (m) cm–1. H NMR
2-Phenyl-5-p-tolyl-1,3,4-selenadiazole (2e): A yellow solid (90%,
0.27 g); m.p. 102–104 °C. Selected IR (KBr): ν = 2918 (w), 1607
([D6]DMSO): δ = 10.49 (s, 2 H, NH), 8.01 [d, J(H,H) = 6.3 Hz, 2
H, ArH], 7.83 [d, J(H,H) = 6.3 Hz, 2 H, ArH], 7.34 (m, 4 H, ArH),
2.37 (s, 3 H, CH3) ppm. 13C NMR ([D6]DMSO): δ = 166.3 (C=O),
165.4 (C=O), 162.9, 142.5, 130.8, 130.7, 130.3, 129.6, 128.1, 116.3,
115.9, 21.6 ppm. MS (ES+): m/z = 295 [M + Na]+, 273 [M + H]+.
˜
(m), 1546 (m), 1494 (m), 1441 (s), 1258 (m), 1061 (s), 962 (m), 817
(s), 757 (m), 685 (s), 578 (m) cm–1. 1H NMR (CD2Cl2): δ = 8.12
[d, J(H,H) = 7.2 Hz, 2 H, ArH], 7.83 [d, J(H,H) = 7.9 Hz, 2 H,
ArH], 7.49 (m, 3 H, ArH), 7.27 [d, J(H,H) = 7.9 Hz, 2 H, ArH],
2.39 (s, 3 H, CH3) ppm. 13C NMR (CD2Cl2): δ = 164.8 (C=N),
164.4 (C=N), 141.9, 131.6, 131.0, 129.9, 129.2, 128.4, 126.8,
4-Bromo-NЈ-(4-methoxybenzoyl)benzohydrazide (1t): A white solid
(81%, 2.80 g); m.p. 240–242 °C. Selected IR (KBr): ν = 3209 (m),
˜
3009 (w), 1600 (vs), 1560 (m), 1467 (s), 1255 (s), 1178 (m), 1031 21.4 ppm. 77Se NMR (CD2Cl2): δ = 683.01 ppm. MS (CI): m/z =
1
(m), 847 (m), 744 (m), 609 (m) cm–1. H NMR ([D6]DMSO): δ =
301 [M + H]+. C15H12N2Se (300.02): calcd. C 60.21, H 4.04, N
9.36; found C 60.31, H 4.29, N 9.51.
10.54 (s, 2 H, NH), 7.90 (m, 4 H, ArH), 7.76 [d, J(H,H) = 7.7 Hz,
1616
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© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2009, 1612–1618

Novel 2,5-Disubstituted 1,3,4-Selenadiazoles
2-(4-Chlorophenyl)-5-phenyl-1,3,4-selenadiazole (2f): A yellow solid
= 299 [M + Na]+. C12H8N2OSe (275.08): calcd. C 52.38, H 2.93,
N 10.18; found C 52.34, H 2.81, N 10.27.
(97%, 0.31 g); m.p. 198–199 °C. Selected IR (KBr): ν = 3424 (w),
˜
1590 (m), 1494 (m), 1440 (vs), 1418 (s), 1238 (m), 1089 (s), 1062
(s), 1010 (m), 965 (m), 845 (m), 820 (m), 762 (s), 686 (m), 661 (m),
578 (m) cm–1. 1H NMR (CD2Cl2): δ = 7.95 (m, 4 H, ArH), 7.47
(m, 5 H, ArH) ppm. 13C NMR (CD2Cl2): δ = 136.9 (C=N), 133.1
(C=N), 131.7, 131.3, 129.9, 129.5, 129.3, 128.7 ppm. 77Se NMR
(CD2Cl2): δ = 688.61 ppm. MS (ESI+): m/z = 343 [M + Na]+.
C14H9ClN2Se (319.56): calcd. C 52.61, H 2.84, N 8.76; found C
52.56, H 2.49, N 8.49.
2-(Furan-2-yl)-5-p-tolyl-1,3,4-selenadiazole (2l):
(90%, 0.24 g); m.p. 98–100 °C. Selected IR (KBr): ν = 3449 (w),
A yellow solid
˜
3104 (w), 2896 (w), 1607 (m), 1492 (m), 1443 (s), 1261 (m), 1061
(m), 1017 (s), 880 (m), 819 (s), 754 (s), 596 (m), 558 (m) cm–1. H
1
NMR (CD2Cl2): δ = 7.79 (m, 3 H), 7.26 (m, 3 H), 6.61 (m, 1 H),
2.42 (s, 3 H, CH3) ppm. 13C NMR (CD2Cl2): δ = 174.1 (C=N),
163.0 (C=N), 145.8, 145.2, 141.9, 129.9, 128.5, 112.7, 110.7,
21.3 ppm. 77Se NMR (CD2Cl2): δ = 688.42 ppm. MS (ESI+): m/z
= 313 [M + Na]+. C13H10N2OSe (289.10): calcd. C 57.15, H 3.69,
N 10.25; found C 56.75, H 3.54, N 10.14.
2-(4-Bromophenyl)-5-phenyl-1,3,4-selenadiazole (2g):
A greenish
yellow solid (95%, 0.35 g); m.p. 90–92 °C. Selected IR (KBr): ν =
˜
3449 (w), 1583 (m), 1492 (m), 1439 (s), 1417 (m), 1256 (m), 1063
2-(4-Bromophenyl)-5-(furan-2-yl)-1,3,4-selenadiazole (2m): A yellow
1
(s), 824 (s), 760 (s), 688 (s), 577 (m) cm–1. H NMR (CD2Cl2): δ =
solid (96%, 0.34 g); m.p. 138–140 °C. Selected IR (KBr): ν = 3449
˜
7.94 (d, 2 H, ArH), 7.83 (d, 2 H, ArH), 7.62 (m, 2 H, ArH), 7.50
(d, 3 H, ArH) ppm. 13C NMR (CD2Cl2): δ = 164.8 (C=N), 164.0
(C=N), 132.5, 131.9, 131.3, 130.0, 129.3, 128.7, 128.3, 126.9 ppm.
77Se NMR (CD2Cl2): δ = 688.75 ppm. MS (CI): m/z = 365 [M +
H]+. C14H9BrN2Se (364.01): calcd. C 46.18, H 2.49, N 7.69; found
C 46.96, H 2.28, N 7.78.
(m), 2920 (w), 2848 (w), 1586 (m), 1489 (s), 1445 (s), 1391 (m),
1254 (m), 1217 (m), 1055 (m), 1018 (m), 879 (m), 815 (s), 743 (s),
591 (m), 554 (m) cm–1. 1H NMR (CD2Cl2): δ = 7.80 (d, 2 H, ArH),
7.61 (d, 2 H, ArH), 7.78 (d, 1 H, FurH), 7.19 (d, 1 H, FurH), 6.61
(m, 1 H, FurH) ppm. 13C NMR (CD2Cl2): δ = 172.7 (C=N), 163.8
(C=N), 146.1, 145.5, 132.5, 130.0, 128.4, 125.4, 112.9, 111.1 ppm.
77Se NMR (CD2Cl2): δ = 693.47 ppm. MS (CI): m/z = 355
[M + H]+. C12H7BrN2OSe (353.97): calcd. C 40.71, H 1.99, N 7.91;
found C 40.96, H 1.92, N 8.01.
2-(4-Fluorophenyl)-5-phenyl-1,3,4-selenadiazole (2h): A greenish yel-
low solid (91%, 0.28 g); m.p. 102–104 °C. Selected IR (KBr): ν =
˜
3427 (w), 3063 (w), 1606 (m), 1550 (m), 1495 (vs), 1445 (m), 1415
(m), 1234 (s), 1152 (m), 1072 (m), 844 (s), 734 (s), 687 (s), 616 (m),
523 (m) cm–1. 1H NMR (CD2Cl2): δ = 8.15 (d, 2 H, ArH), 7.96 (d,
2 H, ArH), 7.53 (m, 3 H, ArH), 7.25 (m, 2 H, ArH) ppm. 13C
NMR (CD2Cl2): δ = 166.3 (C=N), 163.8 (C=N), 131.8, 131.2,
130.7, 129.2, 128.7, 126.8, 117.2, 116.2 ppm. 77Se NMR (CD2Cl2):
δ = 686.62 ppm. MS (ESI+): m/z (%) = 327 [M + Na]+.
C14H9FN2Se (303.10): calcd. C 55.46, H 2.99, N 9.24; found C
55.56, H 2.93, N 9.17.
2-(4-Methoxyphenyl)-5-p-tolyl-1,3,4-selenadiazole (2n): A yellow so-
lid (90%, 0.29 g); m.p. 178–180 °C. Selected IR (KBr): ν = 3450
˜
(w), 2961 (w), 1603 (s), 1513 (m), 1452 (s), 1407 (m), 1307 (m),
1256 (vs), 1177 (m), 1065 (m), 1034 (m), 836 (s), 817 (s), 606 (m),
578 (m) cm–1. 1H NMR (CD2Cl2): δ = 7.85 (m, 4 H, ArH), 7.27
[d, J(H,H) = 7.7 Hz, 2 H, ArH], 6.96 [d, J(H,H) = 7.7 Hz, 2 H,
ArH], 3.85 (s, 3 H, OCH3), 2.39 (s, 3 H, CH3) ppm. 13C NMR
(CD2Cl2): δ = 174.0 (C=N), 162.0 (C=N), 141.7, 130.5, 130.2,
129.9, 128.5, 126.0, 114.5, 55.6, 21.3 ppm. 77Se NMR (CD2Cl2): δ
= 673.66 ppm. MS (ESI+): m/z = 353 [M + Na]+. C16H14N2OSe
(329.17): calcd. C 58.37, H 4.29, N 8.51; found C 58.51, H 3.86, N
8.19.
2-Phenyl-5-(thiophen-2-yl)-1,3,4-selenadiazole (2i):
A yellow oil
(92%, 0.31 g). Selected IR (KBr): ν = 3430 (w), 3060 (w), 1608 (m),
˜
1499 (s), 1447 (m), 1420 (m), 1240 (s), 1076 (m), 739 (s), 690 (s),
618 (m), 525 (m) cm–1. 1H NMR (CD2Cl2): δ = 7.94 (m, 1 H,
thiophen-H), 7.75–7.37 (m, 3 H, ArH), 7.03 (m, 2 H, ArH), 6.24
(m, 1 H, thiophen-H), 6.12 (m, 1 H, thiophen-H) ppm. 13C NMR
(CD2Cl2): δ = 166.6 (C=N), 164.0 (C=N), 131.3, 131.2, 130.8,
129.3, 128.7, 128.3, 127.6, 127.5, 127.1 ppm. 77Se NMR (CD2Cl2):
δ = 688.24 ppm. MS (CI): m/z = 341 [M + H]+. C12H8N2Se2
(337.94): calcd. C 42.63, H 2.39, N 8.28; found C 42.90, H 2.48, N
8.08.
2-(4-Methoxyphenyl)-5-phenyl-1,3,4-selenadiazole (2p): A yellow so-
lid (86%, 0.27 g); m.p. 130–132 °C. Selected IR (KBr): ν = 2936
˜
(w), 2831 (w), 1604 (s), 1513 (m), 1438 (s), 1253 (vs), 1178 (m),
1034 (m), 763 (m) cm–1. 1H NMR (CD2Cl2): δ = 7.91 (m, 4 H,
ArH), 7.48 (m, 3 H, ArH), 6.99 (m, 2 H, ArH), 3.85 (s, 3 H, OCH3)
ppm. 13C NMR (CD2Cl2): δ = 174.5 (C=N), 173.9 (C=N), 133.3,
131.0, 130.2, 129.2, 128.6, 126.3, 125.9, 114.6, 55.6 ppm. 77Se NMR
(CD2Cl2): δ = 677.36 ppm. MS (CI): m/z = 317 [M + H]+.
C15H12N2OSe (315.14): calcd. C 57.15, H 3.04, N 8.89; found C
56.54, H 3.62, N 8.94.
2-Ethoxy-5-phenyl-1,3,4-selenadiazole (2j): A yellow paste (99%,
0.25 g). Selected IR (KBr): ν = 3056 (w), 2926 (w), 1757 (s), 1719
˜
(s), 1690 (m), 1438 (m), 1369 (m), 1307 (m), 1281 (s), 1232 (s), 758
1
(m), 686 (s), 543 (m) cm–1. H NMR (CD2Cl2): δ = 8.14 (m, 2 H,
2-(4-Chlorophenyl)-5-p-tolyl-1,3,4-selenadiazole (2r): A yellow solid
ArH), 7.54 (m, 3 H, ArH), 4.17 (t, 2 H, OCH2), 1.25 (q, 3 H, CH3)
ppm. 13C NMR (CD2Cl2): δ = 135.6 (C=N), 134.4 (C=N), 133.0,
132.4, 132.2, 131.3, 130.8, 64.1, 13.8 ppm. 77Se NMR (CD2Cl2): δ
= 687.45 ppm. MS (CI): m/z = 255 [M + H]+. C10H10N2OSe
(253.07): calcd. C 47.44, H 3.98, N 11.07; found C 47.01, H 3.88,
N 10.93.
(83%, 0.27 g); m.p. 184–186 °C. Selected IR (KBr): ν = 3453 (w),
˜
3074 (w), 2914 (w), 1601 (m), 1588 (m), 1441 (s), 1431 (s), 1396
(m), 1261 (m), 1073 (m), 817 (vs), 577 (m), 470 (m) cm–1. 1H NMR
(CD2Cl2): δ = 8.05 (m, 4 H, ArH), 7.51 [d, J(H,H) = 6.9 Hz, 2 H,
ArH], 7.34 [d, J(H,H) = 6.9 Hz, 2 H, ArH], 2.48 (s, 3 H, CH3)
ppm. 13C NMR (CD2Cl2): δ = 164.9 (C=N), 163.6 (C=N), 142.7,
137.7, 129.9, 129.5, 128.6, 128.1, 126.8, 122.8, 21.4 ppm. 77Se NMR
(CD2Cl2): δ = 684.21 ppm. MS (ESI): m/z = 357 [M + Na]+.
C15H11ClN2Se (333.59): calcd. C 53.99, H 3.32, N 8.40; found C
54.06, H 3.28, N 8.78.
2-(Furan-2-yl)-5-phenyl-1,3,4-selenadiazole (2k):
A yellow solid
(82%, 0.23 g); m.p. 100–102 °C. Selected IR (KBr): ν = 3137 (m),
˜
1634 (m), 1582 (m), 1487 (s), 1453 (s), 1421 (m), 1259 (m), 1222
(m), 1058 (m), 1018 (s), 879 (s), 763 (vs), 750 (vs), 689 (vs), 658 (s),
588 (s), 557 (m) cm–1. 1H NMR (CD2Cl2): δ = 7.94 (m, 2 H, ArH), 2-(4-Fluorophenyl)-5-p-tolyl-1,3,4-selenadiazole (2s): A greenish yel-
7.64 (d, 1 H, FurH), 7.47 (m, 3 H, ArH), 7.17 (d, 1 H, FurH), 6.61
low solid (79%, 0.25 g); m.p. 149–151 °C. Selected IR (KBr): ν =
˜
(m, 1 H, FurH) ppm. 13C NMR (CD2Cl2): δ = 145.9 (C=N), 145.4 3062 (w), 2920 (w), 1607 (m), 1494 (vs), 1228 (s), 1158 (m), 1069
(C=N), 131.9, 131.2, 129.3, 128.7, 126.9, 114.0, 112.8, 112.2,
(m), 1012 (m), 963 (m), 846 (m), 818 (m), 741 (m), 638 (m), 500
1
110.9 ppm. 77Se NMR (CD2Cl2): δ = 692.12 ppm. MS (ESI+): m/z
(m) cm–1. H NMR (CD2Cl2): δ = 8.10 (m, 4 H, ArH), 7.27 (m, 4
Eur. J. Org. Chem. 2009, 1612–1618
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1617

G. Hua, Y. Li, A. L. Fuller, A. M. Z. Slawin, J. D. Woollins
FULL PAPER
H, ArH), 2.61 (s, 3 H, CH3) ppm. 13C NMR (CD2Cl2): δ = 166.6
(C=N), 163.0 (C=N), 142.6, 130.7, 129.9, 129.2, 128.6, 126.8, 116.6,
116.2, 21.4 ppm. 77Se NMR (CD2Cl2): δ = 682.36 ppm. MS (ESI+):
m/z = 341 [M + Na]+. C15H11FN2Se (317.13): calcd. C 56.79, H
3.50, N 8.83; found C 56.66, H 3.28, N 8.98.
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2-(4-Bromophenyl)-5-(4-methoxyphenyl)-1,3,4-selenadiazole (2t): A
yellow solid (75%, 0.30 g); m.p. 148–150 °C. Selected IR (KBr): ν
˜
= 2966 (w), 2838 (w), 1615 (s), 1494 (s), 1478 (m), 1307 (m), 1258
(s), 1126 (m), 1076 (m), 1029 (m), 1009 (m), 839 (s), 742 (s), 503
(m) cm–1. 1H NMR (CD2Cl2): δ = 8.03 (m, 4 H, ArH), 7.68 [d,
J(H,H) = 8.8 Hz, 2 H, ArH], 7.04 [d, J(H,H) = 8.8 Hz, 2 H, ArH],
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163.5 (C=N), 132.4, 130.3, 128.6, 128.2, 126.0, 123.2, 116.3, 114.6,
55.6 ppm. 77Se NMR (CD2Cl2): δ = 678.61 ppm. MS (CI): m/z =
395 [M + H]+. C15H11BrN2OSe (394.04): calcd. C 45.71, H 2.81,
N 7.11; found C 45.96, H 2.68, N 7.31.
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[22] Data for 2g: C14H9BrN2Se, FW = 364.10, space group P21, a
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98.610(8), λ = 90°, U = 629.00(17) Å3, Z = 2; µ = 6.14 mm–1,
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Received: January 7, 2009
Published Online: February 11, 2009
1618
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© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2009, 1612–1618