Synthesis and oxidative ring contraction of 1,5,3,7-dichalcogenadiazocanes. Novel formation of 1,2,4-diselenazolidines, 1,2,4-ditellurazolidines, and 1,2,3,4,5,7-pentathiazocanes

Article abstract of DOI:10.1246/bcsj.79.1913

1,5,3,7-Dithiadiazocanes, 1,5,3,7-diselenadiazocanes, and 1,5,3,7-ditelluradiazocanes were prepared from a primary amine, formalin, and H₂S, NaSeH, or NaTeH, respectively. Oxidation of 1,5,3,7- diselenadiazocanes and 1,5,3,7-ditelluradiazocanes using NBS efficiently afforded 1,2,4-diselenazolidines or 1,2,4-ditellurazolidines, respectively. In contrast, treatment of 1,5,3,7-dithiadiazocanes with bromine-elemental sulfur or disulfur dichloride (S₂Cl₂) afforded 1,2,3,4,5,7- pentathiazocanes. An unusual oxidative conversion of 1,5,3,7- dichalcogenadiazocanes into these products was assumed to proceed through in situ formation of 1,5,3,7-dichalcogenadiazabicyclo[3.3.0]octane-type dications.

Full text of DOI:10.1246/bcsj.79.1913

Ó 2006 The Chemical Society of Japan
Bull. Chem. Soc. Jpn. Vol. 79, No. 12, 1913–1925 (2006) 1913
Synthesis and Oxidative Ring Contraction of 1,5,3,7-Dichalcogena-
diazocanes. Novel Formation of 1,2,4-Diselenazolidines,
1,2,4-Ditellurazolidines, and 1,2,3,4,5,7-Pentathiazocanes
Yuji Takikawa,1 Yutaka Koyama,1 Takamasa Yoshida,1 Kenshiro Makino,1
Hiroki Shibuya,1 Kazuto Sato,1 Tatsuya Otsuka,1 Yuko Shibata,1 Yuki Onuma,1
ꢀ1
Shigenobu Aoyagi,1 Kazuaki Shimada, and Chizuko Kabuto2
1Department of Chemical Engineering, Faculty of Engineering, Iwate University, Morioka, Iwate 020-8551
2Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University,
Aramaki, Aoba-ku, Sendai, 980-8578
Received April 13, 2006; E-mail: shimada@iwate-u.ac.jp
1,5,3,7-Dithiadiazocanes, 1,5,3,7-diselenadiazocanes, and 1,5,3,7-ditelluradiazocanes were prepared from a pri-
mary amine, formalin, and H2S, NaSeH, or NaTeH, respectively. Oxidation of 1,5,3,7-diselenadiazocanes and 1,5,3,7-
ditelluradiazocanes using NBS efficiently afforded 1,2,4-diselenazolidines or 1,2,4-ditellurazolidines, respectively. In
contrast, treatment of 1,5,3,7-dithiadiazocanes with bromine-elemental sulfur or disulfur dichloride (S2Cl2) afforded
1,2,3,4,5,7-pentathiazocanes. An unusual oxidative conversion of 1,5,3,7-dichalcogenadiazocanes into these products
was assumed to proceed through in situ formation of 1,5,3,7-dichalcogenadiazabicyclo[3.3.0]octane-type dications.
Recently, several heterocycles containing heavy chalcogen
atoms are of great interest due to their structures, reactivities,
and their synthetic potentiality as novel precursors for various
useful heterocycles and new substrates for electroconductive
organic materials, and current studies have concentrated on
the synthesis and reactions of cyclic polychalcogenides.1,2
However, in spite of their potential applications, such as
antibacterial drugs, natural flavors, and industrial vulcanizing
agents, there are only a few reports on macrocyclic polysul-
fides because they are difficult to prepare and are labile in
the presence of various reagents.3–15 The lack of convenient
synthetic methods for cyclic polyselenides and polytellurides
has also impeded the structural and synthetic studies of these
compounds except for some limited cyclic diselenides and
ditellurides.16–26 During our studies on cyclic chalcogenoace-
tals, we have reported a variety of chemical conversions of
cyclic polychalcogenoacetals and polychalcogenoaminoacetals
including 1,3,5-triselenanes,27,28 5,6-dihydro-1,3,5-dithiazi-
nanes,29,30 6H-1,3,5-oxachalcogenazines,31,32 and 1,5,3,7-di-
chalcogenadiazocanes A (X ¼ S, Se, and Te).33–35 It was ex-
pected that oxidation of conformationally flexible eight-mem-
bered aminochalcogenoacetals A would undergo transannular
chalcogen–chalcogen interaction to give 1,5,3,7-dichalcogena-
diazabicyclo[3.3.0]octane-type dications B,36–51 which would
undergo further fragmentation to give five-membered cyclic
dichalcogenides C (X ¼ Se and Te) or the related macrocyclic
polysulfides via cyclic disulfides C (X ¼ S)35 by nucleophilic
attack on the methylene carbons of B.52–55 In this paper, we de-
scribe the oxidative ring contraction of 1,5,3,7-dichalcogena-
diazocanes A (X ¼ S, Se, and Te) to give 1,2,4-dichalcogena-
zolidines C (X ¼ Se and Te) or the novel cyclic polysulfides,
1,2,3,4,5,7-pentathiazocanes D (X ¼ S). An unusual oxidative
conversion of C (X ¼ Se and Te) into the corresponding per-
hydro-1,3,5-triazines is also reported in this paper (Scheme 1).
Results and Discussion
Preparation and Conformational Features of 1,5,3,7-
Dithiadiazocanes (1), 1,5,3,7-Diselenadiazocanes (2), and
1,5,3,7-Ditelluradiazocanes (3). 3,7-Dialkyl- and 3,7-diaryl-
1,5,3,7-dithiadiazocanes 1a–1g were prepared by the reaction
of a primary amine, formalin, and H2S gas according to the re-
ported methods.56–59 Compounds 1a–1g were stable toward air
and could be stored for a long time. In the 1H NMR spectra of
1a–1f, a broad singlet in the signals of 4.10–4.90 ppm regions
was observed. Lehn et al. have studied the conformational
analysis of 1,5,3,7-dithiadiazocane rings by using variable
temperature 1H NMR measurement, and they reported that
the conformational interconversion proceeded slowly at room
temperature and that the ꢀGz value for the interconver-
sion between the two preferred conformations, i.e., a crown
and a chair-boat conformation, is approximately 13.4–14.8
kcal molꢁ1 60 Grandjeans et al. also reported the X-ray crystal-
.
lographic study on 1f (R ¼ CH3), in which it was shown that
the 1,5,3,7-dithiadiazocane ring is in a crown-type conforma-
tion in the solid state and the atomic distance between the
61
˚
S-1 and S-5 atoms of 1f is 3.976 A.
1,5,3,7-Diselenadiazocanes (2a–2g) and 1,5,3,7-ditellura-
diazocanes (3a–3e) were synthesized by modifying Draguet’s
method,58 in which an ethanolic solution of a primary amine
was treated with formalin and NaSeH62 or NaTeH,63,64 respec-
tively. In the synthesis of 3, no byproducts originating from
NaTeH- or H2Te-induced reduction of formaldimines were
found,65–70 and 1,2,4-ditellurazolidines 6a–6e were obtained
as major byproducts involving tellurium due to further aerobic
Published on the web December 13, 2006; doi:10.1246/bcsj.79.1913

1914 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
1,5,3,7-Dichalcogenadiazocanes
X
X
[ O ]
X
X
X
X
Nu
R
N
N
R
R
N
N
R
R
N
A (X=S, Se, Te)
B
C
S
8
(X=S)
S
R
N
(S)n
S
D (n=3)
Scheme 1. Oxidative ring contraction of 1,5,3,7-dichalcogenadiazocanes A (X ¼ S, Se, and Te).
solution of 1,5,3,7-diselenadiazocane 2a (R ¼ C6H5) at ꢁ78
ꢂC, and the reaction mixture was stirred for 3 h under an Ar
atmosphere. After quenching the reaction with an aqueous
NaOH solution, the usual workup, and purification of the crude
products by column chromatography on silica gel, 4-phenyl-
1,2,4-diselenazolidine (5a) was obtained as stable reddish
brown prisms in 83% yield along with N-(anilinomethyl)suc-
cinimide 7a (85%).71 Other 1,5,3,7-diselenadiazocanes 2c,
2f, and 2g were also converted into the corresponding 1,2,4-
diselenazolidines 5 in high yields by treating with NBS in a
similar method as shown above. Treatment of 2 with other
oxidizing agents such as mCPBA and t-BuOOH, as well as
the treatment of an CH3CN solution of 2 with a catalytic
Fig. 1. ORTEP drawing of 1,5,3,7-diselenadiazocane 2a.
oxidation of 3 during workup and chromatographic purifica-
tion. All physical data, including MS, IR, 1H NMR, and
13C NMR spectra, were fully consistent with the structures of
2a–2g, and were also identical to the reported data. The struc-
ture of 2a (R ¼ C6H5) was determined by X-ray crystallo-
graphic analysis, and the ORTEP drawing of 2a is shown in
Fig. 1. The crystal data of 2a indicated that the eight-mem-
bered heterocyclic ring of 2 is in a crown-type conformation,
in which two selenium atoms were located close to each other
and the atomic distance between the two selenium atoms was
amount of CuCl2 2H2O (0.1 mol amt.) under an aerobic condi-
ꢃ
tion, was also effective for the conversion from 2 to 5. The
structures of 5 were confirmed by MS, IR, 1H NMR, 13C NMR
spectroscopies, and elemental analysis. The structure of 5c
(R = p-CH3OC6H4) was determined by X-ray crystallograph-
ic analysis, and the X-ray data showed a unique 1,2,4-diselena-
˚
zolidine ring system with a Se–Se bond (2.331 A) and a quasi-
axial p-methoxyphenyl substituent on the nitrogen atom. It is
worth noting that no intermolecular attractive interaction be-
tween the selenium atoms of different molecules of 5 was
observed in the crystal lattice. The ORTEP drawing of 5c is
shown in Fig. 2.
˚
3.858 A. The transannular atomic distance between the Se-1
and Se-5 atoms was thought to be small enough to cause a fac-
ile cationic interaction accompanied by minimal motion of the
atoms of the substrates 2 during the oxidation step.
However, attempts for structurally characterize 3a–3e by X-
ray crystallography were not successful due to their instability
In contrast with the selenium series, 1,5,3,7-ditelluradiazo-
canes 3 underwent facile oxidative ring contraction to give
the corresponding 1,2,4-ditellurazolidines (6) under rather mild
reaction conditions, for example, exposing to air, O2 gas, or
treating with an oxidizing agent (1.0 mol amt.) at ꢁ78 ꢂC or
at rt, etc., and the formation of perhydro-1,3,5-triazinanes (8)
was accompanied as major byproducts in each reaction. The
1
toward air and light. The H NMR and 13C NMR spectral pat-
terns of 3, measured at 25 ꢂC, were similar to those of sulfur
and selenium analogues, 1 (X ¼ S) and 2 (X ¼ Se), respec-
tively. In the dynamic 1H NMR spectrum of 3e (R ¼ p-FC6H4)
in toluene-d8 at ꢁ10 ꢂC, a couple of broad doublet signals
assigned to the gem-methylene protons were observed. The
signals coalesced at þ10 ꢂC, and no significant changes were
observed in the range of 20–80 ꢂC. Thus, the approximate
ꢀGz value for the conformational interconversion of 3e was
estimated to be 54.4 kJ molꢁ1 (¼13:0 kcal molꢁ1). The dy-
namic conformational feature of 3e was similar to those of
2a (R ¼ C6H5),33,36–51,56–59 and the crown conformation was
strongly suggested for the most preferred conformation of 3.
All the results from the syntheses of 1,5,3,7-dichalcogenadi-
azocanes 2 and 3 are summarized in Table 1.
1
physical data of the products including the MS, IR, H NMR,
and 13C NMR spectra as well as the elemental analysis data
were fully consistent with the structures of 6 and 8. The struc-
ture of 6e (R ¼ p-FC6H4) was determined by X-ray crystallo-
graphic analysis, and an ORTEP drawing of 6e is shown in
Fig. 3. It is worth noting that 6e possessed a slightly longer
˚
Te–Te bond (2.756 A) than those of the reported bond lengths
of the common acyclic dialkyl ditellurides. The UV–vis spec-
tra of 6 also had two characteristic absorptions at about 685
ꢀ
and 565 nm due to the n–ꢀ transition of Te–Te bonds,21,25
Oxidative Ring Contraction of 1,5,3,7-Diselenadiazo-
canes (2) and 1,5,3,7-Ditelluradiazocanes (3). A CH2Cl2 so-
lution of NBS (1.1 mol amt.) was added dropwise to a CH2Cl2
and all of the UV–vis spectral patterns of 6a–6e were also dif-
ferent from those of common dialkyl or diaryl ditellurides.
Actually, when a CH2Cl2 solution of 1,2,4-diselenazolidine

Y. Takikawa et al.
Table 1. Preparation of 1,5,3,7-Dichalcogenadiazocanes 1–3
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1915
X
X
X
H X or NaXH
2
N
R
R
N
+
R
N
R
NH2
X
Formalin
1 (X=S)
2 (X=Se)
3 (X=Te)
4 (X=S)
5 (X=Se)
6 (X=Te)
R
X (H2X)
X (NaXH)
Solvent
Yield/%a)
Temp
/ꢂC
Time
/min
1, 2, 3
4, 5, 6
C6H5
p-ClC6H4
S
S
S
S
S
—
—
—
—
—
—
Se
Se
Se
Se
Te
Te
Te
Te
Te
C2H5OH
C2H5OH
C2H5OH
C2H5OH
H2O
C2H5OH
C2H5OH
C2H5OH
C2H5OH
rt
rt
rt
rt
rt
rt
rt
rt
rt
rt
rt
rt
rt
rt
ꢁ10
1440
1440
1440
1440
120
1440
120
120
120
120
10
82 (1a)
63 (1b)
81 (1c)
79 (1d)
22 (1f)
52 (1g)
72 (2a)
89 (2c)
64 (2f)
92 (2g)
72 (3a)c)
59 (3b)c)
61 (3c)c)
62 (3d)c)
41 (3e)c)
0
0
0
0
0
0
0
0
p-CH3OC6H4
p-CH3C6H4
b)
CH3
c-C6H11
C6H5
p-CH3OC6H4
S
—
—
—
—
—
—
—
—
—
b)
CH3
c-C6H11
C6H5
0
0
C2H5OH
H2O
trace (6a)
15 (6b)
18 (6c)
13 (6d)
11 (6e)
p-ClC6H4
p-CH3OC6H4
p-CH3C6H4
p-FC6H4
C2H5OH/H2O
C2H5OH/H2O
C2H5OH/H2O
C2H5OH/H2O
10
10
10
10
a) Isolated yields based on the starting primary amines. b) CH3NH2 HCl was used in place of CH3NH2. c) Com-
ꢃ
pounds 3 were gradually converted into 6 during the usual workup and chromatographic purification on silica gel.
Fig. 2. ORTEP drawing of 1,2,4-diselenazolidine 5c.
Fig. 3. ORTEP drawing of 1,2,4-ditellurazolidine 6e.
5c was treated with NBS (1.1 mol amt.) at ꢁ78 ꢂC for 1 h under
an argon atmosphere, perhydro-1,3,5-triazine 8c (R = p-CH3-
OC6H4) and succinimide 7c (R ¼ p-CH3OC6H4) were ob-
tained in 63 and 4% yields, respectively, along with the extru-
sion of elemental selenium, while mCPBA oxidation of 1,2,4-
ditellurazolidine 6a (R ¼ C6H5) also gave 8a (R ¼ C6H5) in
35% yield.72,73 These results strongly indicated that com-
pounds 8 were afforded through the oxidation of 6 during
the reaction of 3 with oxidizing agents. However, all attempts
to trap or to detect directly the precursors of 8, such as N-aryl-
formaldimines, were not successful, and the reaction pathway
on the conversion of cyclic dichalcogenides 5 and 6 into per-
hydro-1,3,5-triazines 8 has not yet been clarified at this time.
All the results of oxidative ring contraction of 2 and 3 are
shown in Table 2.
dro-1,3,5-thiadiazines 1074,75 and insoluble polymeric products
11 in some cases. Yields of 9 were dramatically improved by
treating 1 with Br2–S8 or S2Cl2. However, the optimal amount
of S2Cl2 for the reactions was just 1.5 mol amt. for 1, and the
use of more than 2.0 molar amount of S2Cl2 mainly afforded
11. In contrast, treatment of 1 bearing alkyl substituents on
the N-3 and N-7 positions only gave a complex mixture. All
of the results of the conversion of 1 into 9 are summarized
in Table 3. The structure of 9a (R ¼ C6H5) was determined
by X-ray crystallographic analysis, and an ORTEP drawing
is shown in Fig. 4. Compound 9a possesses an eight-mem-
bered cyclic pentasulfide ring system with a crown-type con-
formation, which is quite similar to those of the reported
eight-membered polysulfides,61,76–86 such as 1,5,3,7-dithiadi-
azocane 1e, S8, S8O, and heptathiaphosphocanes.
Oxidation of 1,5,3,7-Dithiadiazocanes (1) by Using Br2-
Elemental Sulfur or Disulfur Dichloride. A CH2Cl2 solu-
tion of 1,5,3,7-dithiadiazocanes 1 bearing aromatic substitu-
ents at the N-3 and N-5 atoms was treated with Br2 (1.1
mol amt.) at ꢁ78 ꢂC, and in all cases 1,2,3,4,5,7-pentathiazo-
canes 9 were obtained in moderate yields along with perhy-
Interestingly, 1,2,4-dithiazolidines 4 were not found at all in
the crude products in the cases of the reaction of 1 with Br2,
Br2–S8, or S2Cl2 in contrast to the selenium and tellurium
analogues. Compounds 9 were unexpectedly stable in air at
rt and were unreactive toward various oxidizing agents, such
as mCPBA, aq. H2O2 solution, or CH3CO3H, even at elevated

1916 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
1,5,3,7-Dichalcogenadiazocanes
Table 2. Conversion of 1,5,3,7-Dichalcogenadiazocines (2, 3) into 1,2,4-Dichalcogenazolidines (5, 6)
R
N
O
X
X
Oxidizing Agent
X
X
N
R
R
N
R
N
RNH CH
N
+
2
+
N
N
R
R
O
2 (X=Se)
3 (X=Te)
5 (X=Se)
6 (X=Te)
7
8
Substrate
Yield/%a)
Reagent
(mol amt.)
Solvent
Temp
/ꢂC
Time
/h
R
X
2, 3
5, 6
7
8
C6H5
C6H5
C6H5
C6H5
C6H5
Se
Se
Se
Se
Se
Se
Se
Se
Se
Te
Te
Te
Te
Te
Te
Te
Te
2a
2a
2a
2a
2a
2c
2c
2f
2g
3a
3a
3a
3a
3b
3c
3d
3e
NBS (1.1)
mCPBA (1.1)
t-BuOOH (1.1)
CH2Cl2
CH2Cl2
CH2Cl2
CH3CN
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
ꢁ78
0
rt
rt
rt
ꢁ78
rt
ꢁ78
ꢁ78
rt
2
1
25
96
128
2
197
2
2
83 (5a)
80 (5a)
68 (5a)
54 (5a)
0c)
89 (5c)
88 (5c)
76 (5f)
54 (5g)
62 (6a)e)
72 (6a)
57 (6a)
61 (6a)
61 (6b)
62 (6c)
52 (6d)
64 (6e)
85 (7a)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
CuCl2 2H2O (0.1)b)
ꢃ
O2 gas (excess)
NBS (1.1)
p-CH3OC6H4
p-CH3OC6H4
CH3
c-C6H11
C6H5
C6H5
C6H5
C6H5
p-ClC6H4
p-CH3OC6H4
p-CH3C6H4
p-FC6H4
CuCl2 2H2O (0.1)d)
ꢃ
NBS (1.1)
NBS (1.1)
Air (excess)
O2 gas (excess)
NBS (1.1)
mCPBA (1.1)
NBS (1.1)
NBS (1.1)
3
0
9 (8a)
f)
rt
0.5
0.5
0.5
0.5
0.5
0.5
3
0
13 (7a)
—
ꢁ78
ꢁ78
ꢁ78
ꢁ78
ꢁ78
rt
0
—
—
—
—
f)
f)
f)
f)
0
0
0
0
0
NBS (1.1)
Air (excess)
12 (8e)
a) Isolated yields. b) The reaction was carried out in CH3CN under O2 atmosphere. c) 2a was quantitatively recovered.
d) Aerobic reaction condition. e) 3a was recovered in 27% yield. f) Not isolated.
Table 3. Oxidation of 1,5,3,7-Dithiadiazocanes 1
R
S
N
S
S
S
S
S
Reagent
Additive
R
N
S
R
N
N
R
+
+
N
N
S
S
S
R
R
n
1
9
10
11
Substrate
Yield/%a)
Reagent
(mol amt.)
Additive
(mol amt.)
Solvent
Temp
/ꢂC
Time
/min
R
1
9
10
11
C6H5
C6H5
C6H5
1a
1a
1a
1a
1b
1c
1d
1d
1g
Br2 (1.1)
S2Cl2 (1.5)
NBS (1.1)
mCPBA (1.1)
S2Cl2 (1.5)
S2Cl2 (1.5)
Br2 (1.1)
S8 (0.38)
b)
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
ꢁ78
ꢁ95
ꢁ78
ꢁ78
ꢁ95
ꢁ95
ꢁ78
ꢁ95
ꢁ95
60
300
360
360
420
300
10
54 (9a)
86 (9a)
18 (10a)
0
complex mixture
0
trace
—
—
—
C6H5
0c)
44 (10a)
17 (10b)
0
0
26 (10d)
0
0
0
b)
p-ClC6H4
p-CH3OC6H4
p-CH3C6H4
p-CH3C6H4
c-C6H11
—
—
S8 (0.38)
50 (9b)
31 (9c)
30 (9d)
66 (9d)
d)
e)
—
0
b)
S2Cl2 (1.5)
S2Cl2 (1.0)
—
—
300
120
b)
complex mixture
a) Isolated yields. b) An aqueous solution of Na2S 9H2O (2 mol amt.) and S8 (2 mol amt.) was used for the workup
ꢃ
procedure. c) Compound 1a was recovered in 16% yield. d) A 10% NaOH solution of S8 (2 mol amt.) was used for
the workup procedure. e) Insoluble polymeric byproduct 11 was mainly obtained.
temperature.78–80 The lack of reactivity of 9 toward oxidizing
agents essentially seemed similar to that of elemental sulfur,
and further investigation on the chemical behavior of 9 toward
various oxidants is required. In contrast, treatment of 9 with
nucleophiles, such as propylamine, NaCN, or PPh3, or reduc-
ing agents, such as NaBH4 or LiAlH4, gave a complex mix-
ture, and treating a CH2Cl2 solution of 9 with HCl (gas, ex-
cess) or Et2O BF3 (1.0 mol amt.) mainly afforded insoluble
ꢃ
solids (11). Further treatment of 9a with S2Cl2 (1.0 mol amt.)
at ꢁ78 ꢂC to rt also formed the similar polymeric products
11 and elemental sulfur.
Attempt for Direct Observation of Bicyclic Dichalcogena
Dications (B) by Using NMR. When a CD2Cl2 solution
of 1,5,3,7-dithiadiazocane 1a was treated with S2Cl2 (1.5

Y. Takikawa et al.
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1917
polysulfides 9 were mainly afforded as the thermodynamically
preferable products through thermal equilibration of the reac-
tion mixture in which intermediary cyclic disulfides 4, elemen-
tal sulfur, and several other cyclic and/or acyclic polysulfides
are involved.77 It is worth noting that the signals of 4a, 9a,
or 8a were not observed at all in the NMR spectra, which
suggested that these products were formed during the workup
procedure.
Fig. 4. ORTEP drawing of 1,2,3,4,5,7-pentathiazocane 9a.
In contrast, all attempts for the direct detection of the inter-
mediate of oxidation of 2 by NMR monitoring were unsuccess-
ful. When a CDCl3 solution of 2a was treated with t-BuOOH
(1.1 mol amt.) in an NMR tube and the reaction mixture was
monitored by NMR at 25 ꢂC, no significant signals correspond-
ing to the intermediary dications B were observed in the spec-
trum of the reaction mixture. In our case, the intermediates B
possess methylene groups adjacent to the cationic selenium
atoms. Thus, it was assumed that the fragmentation of B was
initiated by the attack of nucleophiles on the methylene car-
bons of B to give N-(anilinomethyl)succinimide derivatives
7.52–55,87 However, an alternative stepwise ring contraction
mechanism cannot be excluded.
1
13
H NMR (δ, CD Cl ) C NMR (δ, CD Cl )
2
2
2
2
S
C6H5
C6H5
N
N
4.82(br.s)
56.5(t)
S
1a
S Cl
2
2
- 50 °C
Cl
S
5.11(d), 5.16(d)
5.79(d), 5.82(d)
63.9(t), 71.5(t)
C6H5
N
N
C6H5
S
Cl or S Cl
2
E
Plausible Reaction Mechanism for Oxidative Ring Con-
traction of 1,5,3,7-Diselenadiazocanes (2), 1,5,3,7-Ditellura-
diazocanes (3), and 1,5,3,7-Dithiadiazocanes (1). In line
with Furukawa’s extensive works on the formation of cyclic
dichalcogena dications through oxidation of cyclic polychalco-
genides,41–50 diselena dications B (X ¼ Se) having a 1,5,3,7-
diselenadiazabicyclo[3.3.0]octane skeleton were expected to
be generated transiently in the first stage of oxidation of 2.
In our cases, the 1,5,3,7-diselenadiazocane ring in compounds
2 are highly flexible, and the crown-type conformation of the
rings, in which the two selenium atoms occupied the closed
positions, appears to be the most favorable. 1,5,3,7-Ditellura-
diazocanes 3 were more reactive toward oxidizing agents than
those of the selenium analogues 2 to form 1,2,4-ditellurazoli-
dines 6 via intermediary ditellura dications B (X ¼ Te). It is
noteworthy that the conversion of 3 into 6 via exposure to
air was much faster than that of selenium analogues 2 which
is attributed to the lower oxidation potential of tellurium atom
than that of the selenium atom and the conformational prefer-
ence of 3 for transannular Te–Te interaction induced by oxida-
tion of tellurium atom. On the other hand, the reaction of sulfur
analogues 1 with oxidizing agents, such as S2Cl2, initially
formed unsymmetrical sulfonium ion E, and E underwent
transannular S–S bond formation at higher temperatures to
form stable dithia dications B (X ¼ S). In other words, halo-
chalcogenonium cation E (X ¼ Se and Te) is formed in the
primary stage of the reactions and undergoes subsequent facile
ring closure to afford bicyclic dication species B (X ¼ Se and
Te) even at low temperature. Cationic species B were assumed
to be highly reactive toward nucleophilic agents, even H2O,
and to undergo ring fission to give 1,2,4-dichalcogenazolidines
5 (X ¼ Se) and 6 (X ¼ Te) through the attack of H2O on the
carbon atoms adjacent to the cationic chalcogen atoms in B.
However, dithia dications B (X ¼ S) were efficiently convert-
ed into 1,2,3,4,5,7-pentathiazocanes 9 in the presence of ele-
mental sulfur, and 1,2,4-dithiazolidines 4 was not found at
all in the reaction mixture. It was suggested that ring strain
and repulsive interaction between the lone pairs of the two
- Cl
R.T
S
S
C6H5
N
N
C6H5
5.68(br.s)
68.5(t)
B(X=S)
Scheme 2. Change in the chemical shifts of the methylene
proton signals and carbons signals through the 1H and
13C NMR monitoring of the reaction of 1,5,3,7-dithiadi-
azocane 1a (R ¼ C6H5) with S2Cl2 in CD2Cl2 at ꢁ50 ꢂC
to rt.
mol amt.) in an NMR tube at ꢁ50 ꢂC and the reaction was
1
monitored by using H NMR measurement, two pairs of AB-
type doublets (5.11 and 5.16 ppm, and 5.79 and 5.82 ppm, re-
spectively) and a broad singlet (5.68 ppm) appeared along with
several unidentified signals as soon as S2Cl2 was added in the
solution along with the disappearance of the original signals of
1a. Subsequently, the AB-type doublets gradually disappeared
along with the raising up of the measuring temperature. In con-
trast, the singlet signals remained unchanged even when the
temperature was raised up to 25 ꢂC. In the 13C NMR spectrum,
three triplet signals of the corresponding methylene carbons
(63.9, 71.5, and 68.5 ppm) were initially observed and only
the 68.5 ppm-signal remained unchanged at higher tempera-
tures. The significant downfield shifts of the methylene signals
in the H NMR and 13C NMR spectra of the reaction mixture
1
from those of starting 1a strongly suggested that the unsym-
metrical cyclic sulfonium ion E formed initially, and the ther-
mally stable secondary species was assumed to be a symmet-
rical bicyclic dithia dication B (X ¼ S). All the results of the
1H NMR and 13C NMR monitoring of the reaction of 1a with
S2Cl2 are summarized in Scheme 2. These results suggested
that 11 were afforded from 1 through a route involving oxida-
tive transannular S–S bond formation to form B (X ¼ S) and
the subsequent removal of the half part of B by the attack of
a nucleophile, such as H2O, during the usual workup process.
Especially, less-strained eight-membered crown-type cyclic

1918 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
1,5,3,7-Dichalcogenadiazocanes
R
R
+
N
N
X
H
R
N
N
R
X
(X=S)
- H CX
2
S
1 (X=S)
2 (X=Se)
3 (X=Te)
10
R
R
N
N
trimerization
Y
N
R
8
Y
X
X
H
O
N
O
O
HN
R
R
N
N
R
R
N
N
E (X=S, Se, Te)
F
O
7
- Y
[ O ]
(X=Se, Te)
- CH O
2
H O
2
S
S
X
S
X
X
S
Nu
8
R
N
N
R
S
R
N
R
N
X
S
(X=S)
4 (X=S)
5 (X=Se)
6 (X=Te)
B (X=S, Se, Te)
9
Scheme 3. Plausible formation of dichalcogena dications B (X ¼ S, Se, and Te) in the conversion of 1,5,3,7-dichalcogenadiazo-
canes 1–3 into 1,2,4-dichalcogenazolidines 5 and 6 or 1,2,3,4,5,7-pentathiazocanes 9.
neighboring sulfur atoms might reduce the thermal stability of
4 and these factors might be reduced by replacing the sulfur
Experimental
Instruments. The melting points were determined with a
1
atoms to selenium or tellurium atoms due to the much-larger
atomic radii of these heavier chalcogen atoms. Formation of
trace amount of perhydro-1,3,5-triazines 8 were also explained
by the in situ formation and trimerizaiton of N-arylformald-
imines F72,73 generated from the counterparts of B (X ¼ Se
and Te), but an additional or alternative pathway involving
the further oxidation of 4 and 5 is also possible.
In addition, small amounts of 5,6-dihydro-1,3,5-dithiazines
10 were formed along with 1,2,3,4,5,7-pentathiazocanes 9
through the reaction of 1 with S2Cl2. Our preliminary results
on the reactions of 1 with a few Lewis acids indicated that
the aminothioacetal moieties of 1 underwent acid-catalyzed
cleavage to give 10. Therefore, it was suggested that the for-
mation of 10 in these cases were also caused by the contami-
nation of trace amount of HCl in S2Cl2.
Buchi 535 micro-melting-point apparatus. H NMR spectra were
¨
recorded on a Hitachi R-22 (90 MHz) or a Bruker AC-400P
1
(400 MHz) spectrometer, and the chemical shifts of the H NMR
spectra are given in ꢁ relative to internal tetramethylsilane
(TMS). 13C NMR spectra were recorded on a Bruker AC-400P
spectrometer (100 MHz). 77Se NMR spectra were also recorded
on a Bruker AC-400P spectrometer (76 MHz). Mass spectra were
recorded on a Hitachi M-2000 mass spectrometer with electron-
impact ionization at 20 or 70 eV using a direct inlet system. IR
spectra were recorded for thin-film (neat) or KBr disks on a
JASCO FT/IR-7300 spectrometer. Elemental analyses were per-
formed using a Yanagimoto CHN corder MT-5.
Materials.
Column chromatography was performed using
silica gel (Merck, Cat. No. 7734 or 9385) without pretreatment. Di-
chloromethane (CH2Cl2), chloroform (CHCl3), and carbon tetra-
chloride (CCl4) were dried over P4O10 and were freshly distilled
before use. Benzene, hexane, acetonitrile, and triethylamine were
dried over calcium hydride (CaH2) and freshly distilled before
use. Diethyl ether and tetrahydrofuran (THF) were dried over lith-
ium aluminum hydride (LiAlH4) and were freshly distilled before
use. Ethanol and methanol were dried over anhydrous magnesium
sulfate (MgSO4), and were freshly distilled before use. All of the
substrates, reagents, and NMR solvents including aniline, p-chlo-
roaniline, p-methylaniline, p-methoxyaniline, p-fluoroaniline, cy-
All the plausible pathways of formation of the products
through the reactions of 1–3 with oxidizing agents are summa-
rized in Scheme 3.
Conclusion
We have found a novel synthesis and unusual oxidative ring
contraction of 1,5,3,7-dichalcogenadiazocanes 2 and 3 to af-
ford 1,2,4-dichalcogenazolidines 5 and 6 which are proposed
to form via dichalcogena dications B (X ¼ Se and Te). As
well, 1,5,3,7-dithiadiazocanes 1 were found to convert into
1,2,3,4,5,7-pentathiazocanes 9 through a similar pathway in-
volving the in situ formation of dithia dications B (X ¼ S).
Further attempts for the conversion of heterocycles 5, 6, and
9 into novel heterocyclic ring systems are in progress in our
laboratory.
clohexylamine, methylamine hydrochloride (CH3NH2 HCl), pro-
ꢃ
pylamine, 37% formalin, iron(II) sulfide (FeS), N-bromosuccin-
imide (NBS), bromine (Br2), t-butyl hydroperoxide, m-chloroper-
benzoic acid (mCPBA), elemental sulfur, elemental selenium,
elemental tellurium, disulfur dichloride (S2Cl2), boron trifluoride
diethyl ether complex (Et2O BF3), copper(II) chloride dihydrate
ꢃ

Y. Takikawa et al.
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1919
(CuCl2 2H2O), sodium metaperiodate (NaIO4), sodium cyanide
nium powder (4.738 g, 60.0 mmol) in ethanol (30 mL) at 0 ꢂC un-
der an Argon atmosphere, and the reaction mixture was warmed to
room temperature. The resulting NaSeH solution was then treated
with an ethanolic solution (10 mL) of 37% formalin (10 mL,
32.0 mmol) and subsequently with an ethanolic solution (40 mL)
of primary amine (20.0 mmol) for 2 h at room temperature under
an Ar atmosphere. The reaction was quenched with an excess
amount of water, and the insoluble solids were collected by suc-
tion filtration. The solids were washed with dichloromethane
and were purified by recrystallization from hexane–chloroform
to afford 1,5,3,7-diselenadiazocane 2 as colorless solids.
ꢃ
(NaCN), sodium tetrahydroborate (NaBH4), lithium tetrahydro-
aluminate (LiAlH4), triphenylphosphine, sodium metal, sodium
hydroxide, 37% aqueous hydrogen peroxide solution, acetic acid,
concentrated hydrochloric acid, deuteriochloroform (CDCl3), di-
chloromethane-d2 (CD2Cl2), and dimethyl sulfoxide-d6 (DMSO-
d6) were commercially available reagent grade, and were used
without purification.
General Procedure for the Preparation of 1,5,3,7-Dithiadi-
azocanes (1). H2S (gas) was treated with 37% formalin (10 mL,
132 mmol) by bubbling, and subsequently the reaction mixture
was treated with an ethanol solution (10 mL) of primary amine
(30 mmol) at room temperature for 24 h. The reaction was
quenched with an excess amount of water, and the reaction mix-
ture was filtered to obtain the insoluble solids. The crude solids
were then purified by recrystallization from ethyl acetate to afford
1,5,3,7-dithiadiazocanes 1 as colorless solids.
2a (R ¼ C6H5): Colorless needles, mp 184.6–185.8 ꢂC (lit.60
185 ꢂC); MS (m=z) 105 (PhNCH2; bp), 94 (CH2Se; 17%, 80Se); IR
(KBr) 1595, 1505, 1450, 1375, 1340, 1265, 1235, 1200, 1190,
1150, 1040, 1000, 890, 870, 845, 740, 690, 610 cmꢁ1 1H NMR
;
(CDCl3) ꢁ 5.10 (8H, br s), 6.70–7.35 (10H, m); 13C NMR (CDCl3)
ꢁ 51.3 (t), 115.0 (d), 119.8 (d), 129.6 (d), 143.3 (s). Calcd for
C16H18N2Se2: C, 48.50; H, 4.58; N, 7.07%. Found: C, 48.40; H,
4.51; N, 6.99%.
1a (R ¼ C6H5): Colorless plates, mp 179.0–182.0 ꢂC (lit.52–55
184.0–185.0 ꢂC); MS (m=z) 302 (Mþ; 21%), 105 (bp); IR (KBr)
3071, 3028, 3012, 2922, 1596, 1504, 1449, 1368, 1274, 1260,
2c (R ¼ p-CH3OC6H4):
Colorless needles, mp 170.5–
171.8 ꢂC; MS (m=z) 458 (Mþ; 8%, 80Se), 299 (bp), 229 (Mþ/2;
1217, 1204, 1157, 1004, 869, 753, 744 cmꢁ1
;
1H NMR (CDCl3)
ꢁ 4.82 (8H, br s), 6.55–7.55 (10H, m); 13C NMR (CDCl3) ꢁ 56.5
(t), 114.8 (d), 119.3 (d), 129.3 (d), 144.0 (s). Calcd for C16H18-
N2S2: C, 63.54; H, 6.00; N, 9.26%. Found: C, 63.53; H, 6.04;
N, 9.24%.
82%, 80Se); IR (KBr) 2940, 2830, 1500, 1440, 1330, 1040, 800
cmꢁ1 1H NMR (CDCl3) ꢁ 3.72 (6H, s), 5.06 (8H, br s), 6.71
;
(4H, br d, J ¼ 9:1 Hz), 6.82 (4H, br d, J ¼ 9:1 Hz); 13C NMR
(CDCl3) ꢁ 52.5 (t), 55.5 (q), 115.0 (d), 116.6 (d), 137.7 (s), 153.6
(s). Calcd for C18H22N2O2Se2: C, 47.39; H, 4.86; N, 6.14%.
Found: C, 47.45 H, 4.80; N, 5.98%.
1b (R ¼ p-ClC6H4): Colorless plates, mp 175.9–176.6 ꢂC;
MS (m=z) 370 (Mþ; 2%), 45 (bp); IR (KBr) 3043, 1593, 1496,
1449, 1378, 1279, 1209, 1162, 1002, 925, 876, 806, 771, 691,
2f (R ¼ CH3): Colorless needles, mp 157.0–158.0 ꢂC (lit.60
160 ꢂC); MS (m=z) 274 (Mþ; bp, 80Se), 214 (CH3N(CH2Se)2;
55%, 80Se), 94 (CH2Se; 80Se); IR (KBr) 2910, 2870, 1450,
619 cmꢁ1 1H NMR (CDCl3) ꢁ 4.81 (8H, br s), 6.78–6.86 (6H,
;
m), 7.21–7.27 (4H, m); 13C NMR (CDCl3) ꢁ 56.9 (t), 115.9 (d),
124.7 (s), 129.2 (d), 142.3 (s). Calcd for C16H16Cl2N2S2: C,
51.75; H, 4.34; N, 7.54%. Found: C, 52.06; H, 4.32; N, 7.62%.
1c (R ¼ p-CH3OC6H4): Colorless plates, mp 142.0–143.0
ꢂC; MS (m=z) 362 (Mþ; 5%), 135 (bp); IR (KBr) 2935, 1518,
1451, 1397, 1276, 1246, 1206, 1184, 1166, 1038, 1007, 926, 874,
1440, 1400, 1330, 1220, 1160, 1090, 1060, 910, 860, 820 cmꢁ1
;
1H NMR (CDCl3) ꢁ 2.33 (6H, s), 4.43 (4H, br s), 4.61 (4H, br s);
13C NMR (CDCl3) ꢁ 39.9 (t), 60.6 (q). Calcd for C6H14N2Se2: C,
26.48; H, 5.16; N, 10.30%. Found: C, 26.44; H, 5.16; N, 10.09%.
2g (R ¼ c-C6H11):
Colorless needles, mp 140.0–140.3 ꢂC
1
806 cmꢁ1; H NMR (CDCl3) ꢁ 3.74 (6H, s), 4.90 (8H, br s), 6.78
(lit.60 140 ꢂC); MS (m=z) 410 (Mþ; 1%, 80Se), 125 (c-C6H11N-
(CH2)2; 42%), 82 (C6H10; bp); IR (KBr) 2930, 2850, 1440, 1330,
1310, 1280, 1240, 1220, 1130, 1095, 1050, 1020, 850, 760, 650,
(4H, d, J ¼ 9:0 Hz), 6.84 (4H, d, J ¼ 9:0 Hz); 13C NMR (CDCl3)
ꢁ 55.7 (t), 57.4 (q), 114.7 (d), 116.6 (d), 138.4 (s), 153.4 (s). Calcd
for C18H22N2O2S2: C, 59.64; H, 6.12; N, 7.73%. Found: C, 59.41;
H, 6.10; N, 7.70%.
610 cmꢁ1 1H NMR (CDCl3) ꢁ 1.05–2.05 (20H, m), 2.74 (2H,
;
tt, J ¼ 10:0, 3.7 Hz), 4.27 (4H, br s), 5.01 (4H, br s); 13C NMR
(CDCl3) ꢁ 24.5 (t), 25.8 (t), 30.2 (t), 55.7 (d), 57.1 (t). Calcd for
C16H30N2Se2: C, 47.06; H, 7.40; N, 6.86%. Found: C, 46.84; H,
7.54; N, 6.75%.
1d (R ¼ p-CH3C6H4): Colorless plates, mp 155.2–156.8 ꢂC;
MS (m=z) 330 (Mþ; 9%), 46 (bp); IR (KBr) 3003, 2921, 1616,
1520, 1450, 1375, 1267, 1254, 1232, 1200, 1164, 1002, 914, 876,
794, 681, 654 cmꢁ1; 1H NMR (CDCl3) ꢁ 2.24 (6H, s), 4.83 (8H, br
s), 6.72 (4H, d, J ¼ 8:0 Hz), 7.07 (4H, d, J ¼ 8:0 Hz); 13C NMR
(CDCl3) ꢁ 20.5 (q), 57.0 (t), 114.9 (d), 117.9 (d), 129.9 (s), 141.9
(s). Calcd for C18H22N2S2: C, 65.41; H, 6.71; N, 8.48; S, 19.40%.
Found: C, 65.47; H, 6.68; N, 8.44; S, 19.41%.
General Procedure for the Preparation of 1,5,3,7-Ditellura-
diazocanes (3). An aqueous solution (20 mL) of NaBH4 (1.248 g,
33.0 mmol) was added dropwise to a suspension of elemental
tellurium powder (1.914 g, 15.0 mmol) in water (10 mL) at room
temperature under an Ar atmosphere. The resulting aqueous
NaTeH solution was then treated with an aqueous solution
(10 mL) of 37% formalin (5 mL, 16.0 mmol) and then with an etha-
nolic solution (10 mL) of a primary amine (5.00 mmol) for 10 min
at room temperature under an argon atmosphere. The reaction was
quenched with an excess amount of water, and the insoluble solids
were collected by suction filtration. The solids were washed with
water and then with dichloromethane. The crude solid was washed
again with hot benzene to remove the contaminated 1,2,4-ditellra-
zolidine 6 and was purified by recrystallization from chloroform to
afford 1,5,3,7-ditelluradiazocane 3 as yellowish green solids.
3a (R ¼ C6H5): Yellowish green crystals, mp 127.0–128.0 ꢂC
(dec.); MS (m=z) 379 (Mþ ꢁ PhN(CH2)2; 3%, 130Te), 119 (bp);
IR(KBr) 3062, 1594, 1502, 1451, 1375, 1372, 1260, 1201, 1166,
1f (R ¼ CH3): Colorless plates, mp 126.0–128.0 ꢂC (lit.61
127.0–130.0 ꢂC).
1g (R ¼ c-C6H11): Colorless plates, mp 105.5–107.5 ꢂC; MS
(m=z) 314 (Mþ: 6%), 46 (bp); IR (KBr) 2972, 2927, 2825, 1434,
1378, 1355, 1337, 1330, 1244, 1159, 1131, 1105, 1061, 936, 909,
1
874, 865, 764, 663 cmꢁ1; H NMR (CDCl3) ꢁ 1.10–1.22 (6H, m),
1.29–1.37 (4H, m), 1.58–1.60 (2H, m), 1.69–1.74 (4H, m), 1.90–
1.93 (4H, m), 2.78–3.02 (2H, m), 4.15 (4H, br s), 4.89 (4H, br s);
13C NMR (CDCl3) ꢁ 24.6 (t), 25.9 (t), 30.4 (t), 54.1 (d), 61.9 (t).
Calcd for C16H30N2S2: C, 61.10; H, 9.61; N, 8.91%. Found: C,
61.07; H, 9.49; N, 8.97%.
General Procedure for the Preparation of 1,5,3,7-Diselena-
diazocanes (2). An ethanolic solution (70 mL) of NaBH4 (4.540 g,
120 mmol) was added dropwise to a suspension of elemental sele-
993, 800, 751 cmꢁ1 1H NMR (CDCl3) ꢁ 5.12 (8H, br s), 6.60–
;

1920 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
Table 4. Crystal Data for 2a, 5c, 6e, and 9a
1,5,3,7-Dichalcogenadiazocanes
2a (R ¼ C6H5)
5c (R ¼ p-CH3OC6H4)
6e (R ¼ p-FC6H4)
9a (R ¼ C6H5)
Formula
C16H18N2Se2
396.25
C9H11NOSe2
307.11
C8H8FNTe2
392.36
C8H9NS5
279.47
Formula weight
Shape of crystal
Temperature/ꢂC
Crystal system
Space group
Colorless prism
22
Reddish brown prism
22
Dark green needle
22
tetragonal
I41=a (No. 88)
18.699(5)
Colorless prism
22
monoclinic
P21=c (No. 14)
13.876(1)
5.334(1)
21.200(2)
98.97(1)
1550.0(3)
4
monoclinic
P21=c (No. 14)
5.787(5)
9.993(3)
17.828(7)
94.68(5)
1027(1)
monoclinic
P21=c (No. 14)
13.533(3)
4.7633(9)
19.485(3)
110.15(1)
1179.1(4)
4
˚
a/A
˚
b/A
˚
c/A
11.820(5)
ꢄ/ꢂ
˚
V/A
3
4132(2)
16
2.522
Z value
4
1.985
Dcalcd/g cmꢁ3
ꢅ(Cu Kꢂ)/cmꢁ1
ꢅ(Mo Kꢂ)/cmꢁ1
R
1.69
60.45
1.574
87.29
70.84
0.039
0.056
56.10
0.027
0.027
0.032
0.046
0.065
0.067
Rw
7.25 (10H, m); 13C NMR (CDCl3) ꢁ 34.0 (t), 115.2 (d), 119.8 (d),
130.0 (d), 143.1 (s). Calcd for C16H18N2Te2: C, 38.94; H, 3.68; N,
5.68%. Found: C, 39.31; H, 3.79; N, 5.53%.
monochromated Cu Kꢂ radiation (ꢃ ¼ 1:5418 A). The crystal
˚
˚
˚
data are as follows: a ¼ 13:876ð1Þ A, b ¼ 5:334ð1Þ A, c ¼
ꢂ
3
˚
˚
21:200ð2Þ A, ꢄ ¼ 98:97ð1Þ , V ¼ 1550:0ð3Þ A , the space group
P21=c (No. 14), Z ¼ 4, Dcalcd ¼ 1:69 g cmꢁ3, ꢅ(Cu Kꢂ) = 60.45
cmꢁ1. The !-2ꢆ scan mode with a scan rate of 8ꢂ minꢁ1 (!) was
employed with a scan range of 1:40 þ 0:30 tan ꢆ. A total of unique
2762 reflections within 2ꢆ ¼ 126ꢂ were collected. The structure
was solved by a direct method and refined by a full-matrix
least-square method. All non-hydrogen atoms were refined aniso-
tropically and hydrogen atoms found in the successive D-Fourier
map were refined with the riding mode. The final cycle of refine-
ment was carried out using 2317 observed reflections within
Io > 3ꢀðIoÞ and 200 variable parameters converged to the final
R ¼ ꢁjjFoj ꢁ jFcjj=ꢁjFoj value of 0.032 and Rw ¼ ½ꢁwðjFoj ꢁ
3b (R ¼ p-ClC6H4): Yellowish green crystals, mp 141.0–
141.6 ꢂC (dec.); MS (m=z) 531 (Mþ; 35Cl; 0.1%, 130Te, 35Cl),
413 (Mþ ꢁ ArN(CH2)2; 2%, 130Te, 35Cl), 153 (ArN(CH2)2; bp,
35Cl); IR (KBr) 3064, 3040, 2999, 2943, 1594, 1496, 1453, 1375,
1320, 1254, 1196, 1164, 1133, 1121, 1086, 989, 807, 792 cmꢁ1
;
1H NMR (CDCl3) ꢁ 5.05 (8H, br s), 6.53 (4H, d, J ¼ 9:0 Hz),
7.19 (4H, d, J ¼ 9:0 Hz). Calcd for C16H16Cl2N2Te2: C, 34.17;
H, 2.87; N, 4.98%. Found: C, 34.53; H, 2.89; N, 5.06%.
3c (R ¼ p-CH3OC6H4): Yellowish green crystals, mp 110.0–
111.0 ꢂC (dec.); MS (m=z) 409 (Mþ ꢁ ArN(CH2)2; 12%, 130Te),
149 (ArN(CH2)2; bp); IR (KBr) 2991, 2945, 2827, 1580, 1509,
1460, 1374, 1336, 1226, 1207, 1176, 993 cmꢁ1; 1H NMR (CDCl3)
ꢁ 3.71 (6H, s), 5.11 (8H, br s), 6.57 (4H, d, J ¼ 9:1 Hz), 6.80
(4H, d, J ¼ 9:1 Hz); 13C NMR (CDCl3) ꢁ 35.7 (t), 55.6 (q), 115.5
(d), 116.4 (d), 137.4 (s), 153.5 (s). Calcd for C18H22N2O2Te2: C,
39.05; H, 4.01; N, 5.06%. Found: C, 38.73; H, 3.89; N, 5.23%.
3d (R ¼ p-CH3C6H4): Yellowish green crystals, mp 117.0–
118.0 ꢂC (dec.); MS (m=z) 526 (Mþ; 0.1%, 130Te), 91 (p-CH3-
C6H4; bp); IR (KBr) 2919, 1617, 1518, 1372, 1162, 1127, 993,
2
1=2
2
jFcjÞ =ꢁwFo
ꢅ
of 0.046 (Tables 4 and 5).
A Typical Procedure for Oxidation of 1,5,3,7-Diselenadiazo-
canes (2). A dichloromethane solution (40 mL) of NBS (196 mg,
1.10 mmol) was added dropwise to a dichloromethane solution
(150 mL) of 1,5,3,7-diselenadiazocane 2 (1.00 mmol) at ꢁ78 ꢂC
under a nitrogen atmosphere, and the reaction mixture was stirred
at ꢁ78 ꢂC for 2 h. The reaction was quenched with an excess
amount of 10% aqueous NaOH solution and was extracted with
dichloromethane. The organic layer was washed with water and
was dried over anhydrous Na2SO4 powder. After removing the
solvent in vacuo, the residual crude mixture, containing 1,2,4-di-
selenazolidine 5 and succinimide 7, was subjected to chromato-
graphic purification using silica gel. Recrystallization from di-
chloromethane–hexane gave 5 as dark red solids.
1
802 cmꢁ1; H NMR (CDCl3) ꢁ 2.10 (6H, s), 5.28 (8H, br s), 6.53
(4H, d, J ¼ 9:1 Hz), 7.00 (4H, d, J ¼ 9:1 Hz). Calcd for C18H22-
N2Te2: C, 41.45; H, 4.25; N, 5.37%. Found: C, 41.58; H, 4.26;
N, 5.04%.
3e (R ¼ p-FC6H4):
Yellowish green needles, mp 132.0–
132.3 ꢂC (dec.); MS (m=z) 534 (Mþ; 0.1%, 130Te), 397 (Mþ ꢁ
ArN(CH2)2; 1.5%, 130Te), 109 (FC6H4; bp); IR (KBr) 3051, 1595,
Oxidation of 1,5,3,7-Diselenadiazocane 2a Using Oxygen
Gas in the Presence of a Catalytic Amount of Copper(II)
Chloride. An acetonitrile solution (110 mL) of 1,5,3,7-diselena-
1509, 1457, 1374, 1255, 1234, 1201, 1172, 993, 812 cmꢁ1
;
1H NMR (DMSO-d6) ꢁ 5.28 (4H, br s), 5.50 (4H, br s), 6.73 (4H,
dd, J ¼ 9:2, 4.4 Hz), 7.11 (4H, t, J ¼ 8:8 Hz); 13C NMR (DMSO-
d6) ꢁ 33.2 (t), 115.9 (dd, JC{F ¼ 22:0 Hz, JC{H ¼ 18:0 Hz), 116.5
diazocane 2a (317 mg, 0.80 mmol) was treated with CuCl2 2H2O
ꢃ
(14 mg, 0.08 mmol), and an excess amount of oxygen gas was in-
troduced slowly with bubbling to the stirred reaction mixture at
room temperature for 4 days. The reaction was quenched with
an excess amount of water, and the reaction mixture was subjected
to the usual workup. After removing the solvent in vacuo, the
residual crude mixture was subjected to chromatographic purifi-
cation using silica gel. Recrystallization from dichloromethane–
hexane gave 5a in 54% yield as reddish brown needles.
(dd, JC{F ¼ 7:3 Hz, JC{H ¼ 3:0 Hz), 140.4 (s), 155.9 (d, JC{F
¼
235:4 Hz). Calcd for C16H16F2N2Te2: C, 36.29; H, 3.05; N,
5.29%. Found: C, 36.29; H, 3.36; N, 5.29%.
X-ray Crystallographic Analysis of 2a. A colorless prism of
C16H18N2Se2 having approximate dimensions of 0:25 ꢄ 0:30 ꢄ
0:30 mm3 was mounted on a glass fiber. All measurements were
made on a Rigaku automated four-cycle diffractometer (AFC5R),
equipped with a rotating anode (45 kV, 200 mA), using graphite-
Oxidation of 1,5,3,7-Diselenadiazocane 2c Using Air in the

Y. Takikawa et al.
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1921
˚
Table 5. Selected Bond Lengths (A), Bond Angles (deg), and Torsion Angles (deg) for 2a
˚
Bond lengths/A
Bond angles/deg
C(2)–Se(1)–C(3)
Torsion angles/dega)
Se(1)–C(2)–N(1)–C(1)
Se(1)–C(2)
2.002(4)
2.009(4)
1.986(4)
1.986(4)
1.425(4)
1.410(4)
1.403(4)
1.420(4)
1.428(4)
1.402(4)
98.7(2)
96.7(1)
ꢁ85.5(3)
77.7(3)
84.9(3)
ꢁ74.9(3)
87.3(3)
75.8(3)
Se(1)–C(3)
Se(2)–C(1)
Se(2)–C(4)
N(1)–C(1)
N(1)–C(2)
N(1)–C(5)
N(2)–C(3)
N(2)–C(4)
N(2)–C(11)
C(1)–Se(2)–C(4)
C(1)–N(1)–C(2)
C(1)–N(1)–C(5)
C(2)–N(1)–C(5)
C(3)–N(2)–C(4)
C(3)–N(2)–C(11)
C(4)–N(2)–C(11)
Se(2)–C(1)–N(1)
Se(1)–C(2)–N(1)
Se(1)–C(3)–N(2)
Se(2)–C(4)–N(2)
N(1)–C(5)–C(6)
N(1)–C(5)–C(10)
N(2)–C(11)–C(12)
N(2)–C(11)–C(16)
Se(1)–C(2)–N(1)–C(5)
Se(1)–C(3)–N(2)–C(4)
Se(1)–C(3)–N(2)–C(11)
Se(2)–C(1)–N(1)–C(2)
Se(2)–C(1)–N(1)–C(5)
Se(2)–C(4)–N(2)–C(3)
N(1)–C(1)–Se(2)–C(4)
N(1)–C(2)–Se(1)–C(3)
N(1)–C(5)–C(6)–C(7)
N(1)–C(5)–C(10)–C(9)
N(2)–C(3)–Se(1)–C(2)
N(2)–C(4)–Se(2)–C(1)
C(1)–N(1)–C(5)–C(6)
C(2)–N(1)–C(5)–C(6)
C(2)–N(1)–C(5)–C(10)
C(3)–N(2)–C(11)–C(12)
C(3)–N(2)–C(11)–C(16)
C(4)–N(2)–C(11)–C(12)
116.8(3)
120.5(3)
120.4(3)
117.0(3)
120.4(3)
119.4(3)
116.2(2)
118.4(2)
118.2(2)
116.5(2)
120.7(3)
121.8(3)
120.7(3)
122.1(3)
ꢁ86.7(3)
ꢁ100.4(3)
95.5(3)
ꢁ176.8(3)
176.3(3)
ꢁ95.2(3)
100.0(3)
170.7(3)
ꢁ171.9(3)
8.2(4)
165.1(3)
ꢁ16.5(4)
ꢁ175.8(3)
a) The sign is positive if when looking from atom 2 to atom 3 a clockwise motion of atom 1 would super-
impose it on atom 4.
Presence of a Catalytic Amount of Copper(II) Chloride. An
acetonitrile solution (90 mL) of 1,5,3,7-diselenadiazocane 2c
(319 mg, 0.80 mmol) was treated with CuCl2 2H2O (12 mg,
ꢁ 24.6 (t), 25.4 (t), 30.4 (t), 56.7 (d), 59.2 (t). Calcd for C8H15-
NSe2: C, 33.94; H, 5.34; N, 4.95%. Found: C, 33.30; H, 5.32;
N, 4.78%.
ꢃ
0.07 mmol), and the reaction mixture was stirred in air at room
temperature for 8 days. The reaction was quenched with an excess
amount of water, and the reaction mixture was subjected to the
usual workup. After removing the solvent in vacuo, the residual
crude mixture was subjected to chromatographic purification
using silica gel. Recrystallization from dichloromethane–hexane
gave pure 1,2,5-diselenazolidine 5c in 88% yield as reddish brown
needles.
7a (R ¼ C6H5): Colorless plates, mp 170.0–171.0 ꢂC (lit.68–70
171–172 ꢂC); MS (m=z) 204 (Mþ; 30%); IR (KBr) 3368, 1694,
;
1604, 1533, 1415, 1184, 1129, 1071, 938, 816 cmꢁ1 1H NMR
(CDCl3) ꢁ 2.65 (4H, s), 4.80 (1H, br s), 4.99 (2H, d, J ¼ 7:9 Hz),
6.78–6.80 (3H, m), 7.17–7.21 (2H, m). Calcd for C11H12N2O: C,
64.69; H, 5.92; N, 13.72%. Found: C, 64.44; H, 5.89; N, 13.73%.
General Procedure for Oxidation of 1,2,4-Diselenazolidines
(5) or 1,2,4-Ditellurazolidine 6a (R ¼ C6H5) Using NBS. A di-
chloromethane solution (30 mL) of N-bromosuccinimide (0.196 g,
1.10 mmol) was added dropwise to a dichloromethane solution
(100 mL) of 1,2,4-dichalcogenazolidine 5 or 6 (1.00 mmol) at ꢁ78
ꢂC under an argon atmosphere, and the reaction mixture was stir-
red at ꢁ78 ꢂC for 1 h. The reaction was quenched with an excess
amount of 10% aqueous NaOH solution, and was extracted with
dichloromethane. The organic layer was washed with water and
was dried over anhydrous Na2SO4 powder. After removing the
solvent in vacuo, the residual crude mixture, containing succin-
imide 7 and perhydro-1,3,5-triazine 8, was subjected to chromato-
graphic purification using silica gel. Recrystallization from etha-
nol gave 8 as colorless solids.
5a (R ¼ C6H5): Reddish brown prisms, mp 119.0–120.0 ꢂC
(dec.); MS (m=z) 279 (Mþ; 97%, 80Se), 275 (Mþ; bp, 78Se); IR
1
(KBr) 1580, 1485, 1350, 1170, 990, 600 cmꢁ1; H NMR (CDCl3)
ꢁ 5.02 (4H, s), 7.09–7.34 (5H, m). 13C NMR (CDCl3) ꢁ 57.4 (t),
118.8 (d), 124.7 (d), 129.2 (d), 144.8 (s). Calcd for C8H9NSe2:
C, 34.68; H, 3.27; N, 5.06%. Found: C, 34.77; H, 3.29; N, 4.81%.
5c (R ¼ p-CH3OC6H4): Reddish brown needles, mp 111.0–
112.0 ꢂC (dec.); MS (m=z) 309 (Mþ; 39%, 80Se), 147 (Mþ ꢁ Se2;
94%), 134 (Mþ ꢁ Se2 ꢁ CH2 ꢁ 1; bp); IR (KBr) 3042, 2998,
2965, 2839, 1500, 1440, 1350, 1295, 1245, 1030, 970, 830, 610
cmꢁ1 1H NMR (CDCl3) ꢁ 3.75 (3H, s), 4.97 (4H, s), 6.82 (2H,
;
d, J ¼ 8:0 Hz), 7.17 (2H, d, J ¼ 8:0 Hz); 13C NMR (CDCl3) ꢁ
55.9 (q), 59.6 (t), 114.9 (d), 121.2 (d), 139.0 (s), 157.6 (s). Calcd
for C9H11NOSe2: C, 35.21; H, 3.61; N, 4.56%. Found: C, 35.42;
H, 3.62; N, 4.61%.
8a (R ¼ C6H5):
Colorless needles, mp 140.0–140.5 ꢂC
(lit.72,73 140.0–141.0 ꢂC); MS (m=z) 315 (Mþ; 2%), 210 (Mþ ꢁ
C6H5NCH2; 20%), 118 (C6H5N(CH2)2; 12%); IR (KBr) 2942,
2847, 1598, 1499, 1442, 1334, 1163, 752 cmꢁ1; 1H NMR (CDCl3)
ꢁ 4.89 (6H, s), 6.84–7.23 (15H, m).
5f (R ¼ CH3): Reddish brown needles, mp 81.0–82.0 ꢂC;
MS (m=z) 217 (Mþ; 66%, 80Se), 57 (Mþ ꢁ Se2; bp); IR (KBr)
3010, 2960, 1457, 1438, 1407, 1355, 1308, 1178, 1118, 1077,
8e (R ¼ p-FC6H4): Colorless needles, mp 154.0–155.0 ꢂC;
MS (m=z) 370 (Mþ; 5%), 246 (Mþ ꢁ ArNCH2; 50%), 138 (ArN-
(CH2)2; 12%); IR (KBr) 2951, 1479, 1450, 1242, 1222, 1200,
1161, 715 cmꢁ1; 1H NMR (CDCl3) ꢁ 4.76 (6H, s), 6.90 (6H, t, J ¼
9:0 Hz), 6.97 (6H, dd, J ¼ 9:1, 4.6 Hz). Calcd for C21H18F3N3: C,
68.28; H, 4.91; N, 11.38%. Found: C, 68.21; H, 4.97; N, 11.33%.
A Typical Procedure for Oxidation of 1,5,3,7-Ditelluradi-
1
1051, 855 cmꢁ1; H NMR (CDCl3) ꢁ 2.14 (3H, s), 4.66 (4H, s);
13C NMR (CDCl3) ꢁ 41.2 (t), 64.6 (q). Calcd for C3H7NSe2: C,
16.76; H, 3.28; N, 6.51%. Found: C, 16.71; H, 3.27; N, 6.51%.
5g (R ¼ c-C6H11): Reddish brown needles, mp 68 ꢂC (dec.);
MS (m=z) 289 (Mþ; 6%, 80Se), 124 (Mþ ꢁ Se2 ꢁ 1; bp); IR (KBr)
3042, 2931, 2851, 1439, 1182, 1063, 920, 819 cmꢁ1 1H NMR
;
(CDCl3) ꢁ 1.10–2.10 (11H, m), 4.80 (4H, s); 13C NMR (CDCl3)
azocanes (3).
A dichloromethane solution (50 mL) of NBS

1922 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
1,5,3,7-Dichalcogenadiazocanes
(98 mg, 0.55 mmol) was added dropwise to a dichloromethane
solution (100 mL) of 1,5,3,7-ditelluradiazocane 3 (0.50 mmol) at
ꢁ78 ꢂC under an argon atmosphere, and the reaction mixture was
stirred at ꢁ78 ꢂC for 30 min. The reaction was quenched with an
excess amount of 10% aqueous NaOH solution, and was extracted
with dichloromethane. The organic layer was washed with water
and was dried over anhydrous Na2SO4 powder. After removing
the solvent in vacuo, the residual crude mixture, containing 1,2,4-
ditellurazolidine 6 and succinimide 7, was subjected to recrystal-
lization from dichloromethane–hexane gave pure 1,2,4-ditellura-
zolidine 6 as brownish green solids. The filtrate was subjected
to chromatographic purification using silica gel and the subse-
quent recrystallization from hexane–dichloromethane to afford
succinimide 7.
General Procedure for Aerobic Oxidation of 1,5,3,7-Ditel-
luradiazocanes (3). A dichloromethane solution (150 mL) of
1,5,3,7-ditelluradiazocane 3 (0.80 mmol) was stirred in air at room
temperature for 3 h. The reaction was then filtrated to remove the
precipitated elemental tellurium. After removing the solvent of
the filtrate in vacuo, the residual crude mixture was subjected to
recrystallization to give 1,2,4-ditellurazolidine 6 as brownish
green solids.
bon tetrachloride solution (20 mL) of bromine (Br2, 196 mg,
1.10 mmol) was added dropwise to a dichloromethane solution
(130 mL) of 1,5,3,7-dithiadiazocane 1 (1.50 mmol) and elemental
sulfur (144 mg, 0.56 mmol) at ꢁ78 ꢂC under an argon atmosphere,
and the reaction mixture was stirred at ꢁ78 ꢂC for 10–60 min. The
reaction was quenched with an excess amount of 10% aqueous
NaOH solution, and was extracted with dichloromethane. The
organic layer was washed with water and was dried over an-
hydrous sodium sulfate powder. After removing the solvent
in vacuo, the residual yellow solid was subjected to chromato-
graphic purification using silica gel to obtain 1,2,3,4,5,7-penta-
thiazocane 9 and perhydro-1,3,5-thiadiazine 8. Recrystallization
from ethanol gave pure 1,2,3,4,5,7-pentathiazocane 9 as pale yel-
low solids.
9a (R ¼ C6H5): Pale yellow needles, mp 123.0–124.0 ꢂC
(dec.); MS (m=z) 247 (Mþ ꢁ S; 4%), 215 (Mþ ꢁ S2; 5%), 183
(Mþ ꢁ S3; 68%), 119 (Mþ ꢁ S5; 80%), 91 (bp); IR (KBr) 3060,
3039, 3029, 1596, 1503, 1440, 1365, 1347, 1270, 1238 cmꢁ1
;
1H NMR (CDCl3) ꢁ 4.79 (2H, d, J ¼ 15:0 Hz), 5.70 (2H, d, J ¼
15:0 Hz), 6.60–7.50 (5H, m); 13C NMR (CDCl3) ꢁ 65.9 (dd),
113.8 (d), 120.5 (d), 129.9 (d), 141.9 (s). Calcd for C8H9NS5:
C, 34.38; H, 3.25; N, 5.10; S, 57.37%. Found: C, 34.33; H,
3.15; N, 5.03; S, 56.93%.
6a (R ¼ C6H5): Brownish green crystals, mp 104.0–104.5 ꢂC
(dec.); MS (m=z) 379 (Mþ; 9%, 130Te), 119 (Mþ ꢁ Te2; bp); IR
(KBr) 3045, 2962, 1597, 1498, 1371, 1249, 1132, 1002, 753, 682
9b (R ¼ p-ClC6H4): Pale yellow needles, mp 128.7–129.5
ꢂC; MS (m=z) 313 (Mþ; 4%), 281 (Mþ ꢁ S; 1%), 250 (Mþ ꢁ S2;
6%), 217 (Mþ ꢁ S3; 21%), 64 (S2; bp); IR (KBr) 2930, 2366,
cmꢁ1 1H NMR (CDCl3) ꢁ 5.37 (4H, br s), 6.90–7.50 (5H, m);
;
13C NMR (CDCl3) ꢁ 36.6 (t), 118.1 (d), 125.0 (d), 129.3 (d), 144.9
(s). Calcd for C8H9NTe2: C, 25.67; H, 2.40; N, 3.74%. Found: C,
25.17; H, 2.40; N, 3.51%.
1863, 1597, 1495, 1441, 1370, 1326, 1268, 1238, 890, 806 cmꢁ1
;
1H NMR (CDCl3) ꢁ 4.79 (2H, d, J ¼ 15:0 Hz), 5.62 (2H, d, J ¼
15:0 Hz), 6.67 (2H, d, J ¼ 9:0 Hz), 7.30 (2H, d, J ¼ 9:0 Hz);
13C NMR (CDCl3) ꢁ 65.6 (d), 114.9 (d), 125.8 (d), 129.7 (d),
140.4 (s). Calcd for C8H8ClNS5: C, 30.61; H, 2.57; N, 4.40%.
Found: C, 30.53; H, 2.65; N, 4.40%.
6b (R ¼ p-ClC6H4): Metallic green powder, mp 134.0–135.0
ꢂC (dec.); MS (m=z) 412 (Mþ; 4%, 130Te, 35Cl), 153 (Mþ ꢁ Te2;
bp); IR (KBr) 3088, 3069, 3054, 2972, 1589, 1493, 1457, 1440,
1360, 1312, 1243, 1165, 1131, 1092, 991, 863, 817, 791, 769
9c (R ¼ p-CH3OC6H4):
Pale yellow needles, mp 91.2–
1
cmꢁ1; H NMR (CDCl3) ꢁ 5.30 (4H, br s), 7.11 (2H, d, J ¼ 8:9
91.8 ꢂC (dec.); MS (m=z) 277 (Mþ ꢁ S; 0.2%), 245 (Mþ ꢁ S2;
2%), 213 (Mþ ꢁ S3; 68%), 135 (Mþ ꢁ S5; 90%), 64 (S2; bp); IR
(KBr) 3047, 2992, 2948, 2920, 2827, 1578, 1511, 1436, 1364,
Hz), 7.27 (2H, d, J ¼ 8:9 Hz). Calcd for C8H8ClNTe2: C, 23.50;
H, 1.97; N, 3.43%. Found: C, 23.35; H, 1.82; N, 3.06%.
6c (R ¼ p-CH3OC6H4): Metallic green plates, mp 111.0–
111.5 ꢂC (dec.); MS (m=z) 409 (Mþ; 0.9%, 130Te), 149 (Mþ ꢁ
Te2; bp); IR (KBr) 3044, 2952, 2932, 1611, 1510, 1470, 1392,
1247, 1182, 1127, 1036, 821 cmꢁ1; 1H NMR (CDCl3) ꢁ 3.76 (3H,
s), 5.32 (4H, br s), 6.84 (2H, d, J ¼ 9:1 Hz), 7.12 (2H, d, J ¼ 9:1
Hz); 13C NMR (CDCl3) ꢁ 38.5 (t), 55.4 (q), 114.5 (d), 119.7 (d),
137.4 (s), 157.3 (s). Calcd for C9H11NOTe2: C, 26.73; H, 2.74;
N, 3.46%. Found: C, 26.66; H, 2.74; N, 3.58%.
1274, 1249, 1207, 1186, 1143, 1045 cmꢁ1 1H NMR (CDCl3) ꢁ
;
3.78 (3H, s), 4.79 (2H, d, J ¼ 15:0 Hz), 5.66 (2H, d, J ¼ 15:0 Hz),
6.74 (2H, d, J ¼ 9:1 Hz), 6.92 (2H, d, J ¼ 9:1 Hz); 13C NMR
(CDCl3) ꢁ 55.6 (q), 66.7 (d), 115.4 (d), 136.0 (d), 154.2 (s). Calcd
for C9H11NOS5: C, 34.93; H, 3.58; N, 4.53%. Found: C, 35.21; H,
3.57; N, 4.40%.
9d (R ¼ p-CH3C6H4): Pale yellow needles, mp 135.0–136.0
ꢂC (dec.); MS (m=z) 293 (Mþ; 0.1%), 261 (Mþ ꢁ S; 0.1%), 229
(Mþ ꢁ S2; 15%), 197 (Mþ ꢁ S3; 39%), 133 (Mþ ꢁ S5; 45%), 105
(bp), 64 (S2; 66); IR (KBr) 2917, 2852, 1616, 1577, 1519, 1441,
6d (R ¼ p-CH3C6H4): Metallic green needles, mp 111.0–
112.0 ꢂC (dec.); MS (m=z) 393 (Mþ; 2%, 130Te), 133 (Mþ ꢁ Te2;
bp); IR (KBr) 2920, 1516, 1364, 1237, 1166, 1127, 991, 799
1367, 1267, 1235, 1206, 1195, 1152, 1032, 890 cmꢁ1 1H NMR
;
cmꢁ1
;
1H NMR (CDCl3) ꢁ 2.29 (3H, s), 5.34 (4H, br s), 7.05–
(CDCl3) ꢁ 2.29 (3H, s), 4.78 (2H, d, J ¼ 15:0 Hz), 5.68 (2H, d,
J ¼ 15:0 Hz), 6.69 (2H, d, J ¼ 8:3 Hz), 7.15 (2H, d, J ¼ 8:3 Hz);
13C NMR (CDCl3) ꢁ 20.2 (q), 66.1 (dd), 113.8 (d), 130.0 (d),
130.2 (d), 130.6 (s). Calcd for C9H11NS5: C, 36.83; H, 3.78; N,
4.77%. Found: C, 36.80; H, 3.76, N, 4.60%.
7.12 (4H, m); 13C NMR (CDCl3) ꢁ 20.8 (q), 37.4 (t), 117.9 (d),
129.9 (d), 134.8 (s), 141.4 (s). Calcd for C9H11NTe2: C, 27.83;
H, 2.85; N, 3.61%. Found: C, 27.35; H, 2.68; N, 3.43%.
6e (R ¼ p-FC6H4): Metallic dark green plates, mp 143.0–
144.0 ꢂC (dec.); MS (m=z) 397 (Mþ; 99%, 130Te), 260 (Te2; bp),
138 (Mþ ꢁ Te2; 69%), 110 (FC6H4N; 90%); IR (KBr) 3068,
10a (R ¼ C6H5): Colorless prisms, mp 103.0–105.0 ꢂC (lit.88
105 ꢂC); IR (KBr) 3025, 2918, 1600, 1579, 1497, 1446, 1351
3049, 1501, 1359, 1229, 1158, 1135, 1108, 1052, 990 cmꢁ1
;
cmꢁ1; H NMR (CDCl3) ꢁ 4.93 (4H, s), 5.17 (2H, s), 6.78–7.15
1
1H NMR (DMSO-d6) ꢁ 5.45 (4H, br s), 7.12–7.27 (4H, m);
13C NMR (DMSO-d6) ꢁ 38.2 (t), 115.6 (dd, JC{F ¼ 21:9 Hz,
JC{H ¼ 21:7 Hz), 119.4 (dd, JC{F ¼ 8:2 Hz, JC{H ¼ 4:0 Hz), 139.5
(s), 158.9 (d, JC{F ¼ 240:0 Hz). Calcd for C8H8FNTe2: C, 24.49;
H, 2.06; N, 3.57%. Found: C, 24.30; H, 2.34; N, 3.63%.
(10H, m).
10b (R ¼ p-ClC6H4): Colorless prisms, mp 149.7–150.6 ꢂC;
MS (m=z) 324 (Mþ; 11%), 185 (Mþ ꢁ CH2=NC6H4Cl; 32%),
139 (CH2=NC6H4Cl; bp), 111 (C6H4Cl; 31%); IR (KBr) 2927,
1600, 1589, 1492, 1234, 940, 562 cmꢁ1; 1H NMR (CDCl3) ꢁ 4.88
(4H, s), 5.11 (2H, s), 6.88 (4H, d, J ¼ 9:0 Hz), 7.08 (4H, d, J ¼
9:0 Hz); 13C NMR (CDCl3) ꢁ 55.8 (s), 69.9 (s), 119.1 (d), 125.8
General Procedure for Oxidation of 1,5,3,7-Dithiadiazocane
(1) Using Bromine in the Presence of Elemental Sulfur. A car-

Y. Takikawa et al.
Table 6. Selected Bond Lengths (A) and Bond Angles (deg) for 5c and 6e
Bond lengths for 5c Bond angles for 5c Bond length for 6e
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1923
˚
Bond angles for 6e
Se(1)–Se(2)
Se(1)–C(1)
Se(2)–C(2)
N(3)–C(1)
N(3)–C(2)
2.331(2)
Se(2)–Se(1)–C(1)
88.9(4)
90.2(3)
112(1)
116.9(9)
119(1)
Te(1)–Te(2)
Te(1)–C(1)
Te(2)–C(2)
N(1)–C(1)
N(1)–C(2)
N(1)–C(3)
2.7561(8)
2.263(8)
2.254(9)
1.404(9)
1.41(1)
Te(2)–Te(1)–C(1)
83.8(2)
85.9(2)
2.05(1)
2.07(1)
1.43(1)
1.37(1)
Se(1)–Se(2)–C(2)
C(1)–N(3)–C(2)
C(1)–N(3)–C(60)
C(2)–N(3)–C(60)
Se(1)–C(1)–N(3)
Se(2)–C(2)–N(3)
Te(1)–Te(2)–C(2)
C(1)–N(1)–C(2)
Te(1)–C(1)–N(1)
Te(2)–C(2)–N(1)
N(1)–C(3)–C(4)
N(1)–C(3)–C(8)
113.3(7)
112.2(5)
110.7(5)
120.9(6)
120.9(7)
108.2(7)
110.3(7)
1.422(8)
(s), 128.9 (d), 145.9 (s). Calcd for C15H14Cl2N2S: C, 55.39; H,
4.34; N, 8.61%. Found: C, 55.21; H, 4.32; N, 8.57%.
minimum peaks on the final difference Fourier map corresponds
to 0.61 and ꢁ0:45 eAꢁ1, respectively (Tables 4 and 6). Crystal-
˚
10d (R ¼ p-CH3C6H4): Colorless prisms, mp 96.1–97.6 ꢂC;
MS (m=z) 284 (Mþ; 16%), 165 (Mþ ꢁ CH2=NC6H4CH3; 18%),
119 (CH2=NC6H4CH3; bp), 91 (C6H4CH3; 63%); IR (KBr) 2916,
lographic data have been deposited at the CCDC, 12, Union
Road, Cambridge, CB2 1EZ, UK, and the copies can be obtained
on request, free of charge, by quoting the publication citation
and the deposition number CCDC 157641 (via http://www.
ccdc.cam.ac.uk/conts/retrieving.html or Fax: +44 1223 336033;
e-mail: deposit@ccdc.cam.ac.uk). The data are also deposited as
Document No. 06105 at the Office of the Editor of Bull. Chem.
Soc. Jpn.
The X-ray Crystallographic Analysis of 9a. A colorless
prism of C8H9NS5 having approximate dimensions of 0:30 ꢄ
0:20 ꢄ 0:20 mm3 was mounted on a glass fiber. All measurements
were made on a Rigaku AFC5R diffractometer, equipped with a
rotating anode (40 kV, 180 mA), using graphite-monochromated
1617, 1573, 1449, 1357, 1224, 1068, 928, 562 cmꢁ1 1H NMR
;
(CDCl3) ꢁ 2.21 (3H, s), 4.87 (4H, s), 5.04 (2H, s), 6.89 (4H, d,
J ¼ 8:5 Hz), 6.98 (4H, d, J ¼ 8:5 Hz); 13C NMR (CDCl3) ꢁ 20.4
(q), 54.3 (s), 70.1 (s), 118.0 (d), 129.5 (d), 129.8 (s), 145.4 (s).
Calcd for C17H20N2S: C, 71.79; H, 7.09; N, 9.85%. Found: C,
71.84; H, 7.09; N, 9.65%.
11a (R ¼ C6H5): Colorless solid. Calcd for C8H9NS5: C,
52.42; H, 4.95; N, 7.64%. Found: C, 52.97; H, 5.27; N, 7.87%.
X-ray Crystallographic Analysis of 5c. A reddish brown
prism of C9H11NOSe2 having approximate dimensions of 0:25 ꢄ
0:10 ꢄ 0:25 mm3 was mounted on a glass fiber. All measurements
were made on a Rigaku AFC5R diffractometer, equipped with
a rotating anode (45 kV, 200 mA), using graphite-monochro-
˚
Cu Kꢂ radiation (ꢃ ¼ 1:54178 A). The crystal data are as follows:
ꢂ
˚
a ¼ 13:533ð3Þ, b ¼ 4:7633ð9Þ, c ¼ 19:485ð3Þ A, ꢄ ¼ 110:15ð1Þ ,
3
˚
V ¼ 1179:1ð4Þ A , the space group P21=c (No. 14), Z ¼ 4,
mated Mo Kꢂ radiation (ꢃ ¼ 0:71069 A). The crystal data are
Dcalcd ¼ 1:574 g cmꢁ3, ꢅ(Cu Kꢂ) = 87.29 cmꢁ1. The !-2ꢆ scan
mode with a scan rate of 4ꢂ minꢁ1 (!) was employed with a scan
range of 1:30 þ 0:30 tan ꢆ. A total of unique 2542 reflections
within 2ꢆ ¼ 125:7ꢂ were collected. The structure was solved by
a direct method and refined by a full-matrix least-square method.
All non-hydrogen atoms were refined anisotropically and hydro-
gen atoms found in the successive D-Fourier map were refined
isotropically. The final cycle of refinement was carried out using
1716 observed reflections within Io > 3:00ꢀðIoÞ and 163 variable
parameters converged to the final R ¼ ꢁjjFoj ꢁ jFcjj=ꢁjFoj value
˚
˚
˚
˚
as follows: a ¼ 5:787ð5Þ A, b ¼ 9:993ð3Þ A, c ¼ 17:878ð7Þ A,
ꢂ
3
˚
ꢄ ¼ 94:68ð5Þ , V ¼ 1027ð1Þ A , the space group P21=c (No. 14),
Z ¼ 4, Dcalcd ¼ 1:985 g cmꢁ3, ꢅ(Mo Kꢂ) = 70.84 cmꢁ1. The !-
2ꢆ scan mode with a scan rate of 8ꢂ minꢁ1 (!) was employed with
a scan range of 1:00 þ 0:30 tan ꢆ. A total of unique 2889 reflec-
tions within 2ꢆ ¼ 55ꢂ were collected. The structure was solved
by a direct method and refined by a full-matrix least-square meth-
od. All non-hydrogen atoms were refined anisotropically and hy-
drogen atoms found in the successive D-Fourier map were refined
with the riding mode. The final cycle of refinement was carried out
using 1389 observed reflections within Io > 1:2ꢀðIoÞ and 132 var-
iable parameters converged to the final R ¼ ꢁjjFoj ꢁ jFcjj=ꢁjFoj
2
1=2
2
of 0.065 and Rw ¼ ½ꢁwðjFoj ꢁ jFcjÞ =ꢁwFo
ꢅ
of 0.067. The
maximum and minimum peaks on the final difference Fourier
map corresponds to 0.62 and ꢁ0:32 eAꢁ1, respectively (Tables 4
˚
2
1=2
2
value of 0.039 and Rw ¼ ½ꢁwðjFoj ꢁ jFcjÞ =ꢁwFo
ꢅ
of 0.056
and 7).
(Tables 4 and 6).
Attempts for mCPBA or Peracid Oxidation of 1,2,3,4,5,7-
Pentathiazocane 9a. A dichloromethane solution (100 mL) of
1,2,3,4,5,7-pentathiazocane 9a (279 mg, 1.00 mmol) was treated
with mCPBA (193 mg, 1.10 mmol) or acetic acid (66 mg, 1.1
mmol) and 34.5% aq. H2O2 solution (91 mg, 3.50 mmol) at rt,
and then the mixture was refluxed for 1 h. The reaction was
quenched with an excess amount of saturated aqueous Na2SO3
solution, and was extracted with dichloromethane. The organic
layer was washed with saturated NaHCO3 solution and with water
and was dried over anhydrous Na2SO4 powder. After removing
the solvent in vacuo, substrate 9a (263 mg, 94% yield in both
cases) was recovered.
X-ray Crystallographic Analysis of 6e. A dark plate crystal
of C8H8FNTe2 having approximate dimensions of 0:05 ꢄ 0:10 ꢄ
0:20 mm3 was mounted on a glass fiber. All measurements were
made on a Rigaku/MSC CCD diffractometer (50 kV, 40 mA), us-
˚
ing graphite-monochromated Mo Kꢂ radiation (ꢃ ¼ 0:71069 A).
˚
The crystal data are as follows: a ¼ 18:699ð5Þ A, c ¼ 11:820ð5Þ
3
˚
˚
A, V ¼ 4132ð2Þ A . the space group I41=a (No. 88), Z ¼ 16,
Dcalcd ¼ 2:522 g cmꢁ3, ꢅ(Mo Kꢂ) = 56.10 cmꢁ1. A sweep of
data was done using ! oscillation mode. A total of 13898 reflec-
tions within 2ꢆ ¼ 55ꢂ were collected, of which 2434 were unique
(Rint ¼ 0:034). The structure was solved by a direct method and
refined by a full-matrix least-square method. All non-hydrogen
atoms were refined anisotropically and hydrogen atoms found in
the successive D-Fourier map were refined isotropically. The final
cycle of refinement was carried out using 1354 observed reflec-
tions within Io > 3:00ꢀðIoÞ and 141 variable parameters con-
verged to the final R ¼ ꢁjjFoj ꢁ jFcjj=ꢁjFoj value of 0.027 and
This work was partially supported by Grant-in-Aid for
Scientific Research (No. 12650843) from the Ministry of
Education, Culture, Sports, Science and Technology. We thank
Ms. Yoriko Fujisawa in Iwate University for the elemental
analysis measurement.
2
1=2
2
Rw ¼ ½ꢁwðjFoj ꢁ jFcjÞ =ꢁwFo
ꢅ
of 0.027. The maximum and

1924 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
1,5,3,7-Dichalcogenadiazocanes
˚
Table 7. Selected Bond Lengths (A), Bond Angles (deg), Torsion Angles (deg), and Spacial Contacts (A) for 9a
˚
˚
Bond lengths/A
˚
Spacial contacts/A
Bond angles/deg
S(2)–S(1)–C(1)
Torsion angles/deg
S(1)–S(2)–S(3)–S(4)
C(1)–S(1)
1.845(8)
2.023(2)
2.046(2)
2.046(2)
2.032(2)
1.865(5)
1.409(6)
1.424(5)
1.398(6)
104.5(2)
107.87(8)
107.03(10)
108.26(9)
104.4(2)
118.4(4)
120.0(4)
121.5(3)
116.6(3)
ꢁ89.4(1)
104.0(4)
ꢁ72.1(5)
ꢁ99.1(4)
89.0(1)
S(1)–S(3)
S(1)–S(4)
S(1)–S(5)
S(2)–S(4)
S(2)–S(5)
S(3)–S(5)
3.289(2)
4.256(2)
4.267(2)
3.290(2)
4.264(2)
3.304(2)
S(1)–S(2)
S(2)–S(3)
S(3)–S(4)
S(4)–S(5)
S(5)–C(2)
C(2)–N(1)
C(1)–N(1)
N(1)–C(3)
S(1)–S(2)–S(3)
S(2)–S(3)–S(4)
S(3)–S(4)–S(5)
S(4)–S(5)–C(2)
C(1)–N(1)–C(2)
C(1)–N(1)–C(3)
C(2)–N(1)–C(3)
S(1)–C(1)–N(1)
S(1)–C(1)–N(1)–C(2)
S(1)–C(1)–N(1)–C(3)
S(2)–S(1)–C(1)–N(1)
S(2)–S(3)–S(4)–S(5)
S(3)–S(2)–S(1)–C(1)
S(3)–S(4)–S(5)–C(2)
S(4)–S(5)–C(2)–N(1)
S(3)–S(4)–S(5)–C(2)
S(4)–S(5)–C(2)–N(1)
S(5)–C(2)–N(1)–C(1)
S(5)–C(2)–N(1)–C(3)
92.1(2)
ꢁ91.9(2)
99.3(4)
ꢁ91.2(2)
99.3(4)
ꢁ104.3(4)
71.8(5)
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