Preparation and reactivities of novel (diacetoxyiodo)arenes bearing heteroaromatics

Full text of DOI:10.1021/jo001186n

J . Org. Chem. 2000, 65, 8391-8394
8391
(2a ), 3-(diacetoxyiodo)thiophene (2b ), N-tosyl-4-(diace-
toxyiodo)pyrrazole (2c), and N-trifluoromethanesulfonyl-
4-(diacetoxyiodo)pyrrazole (2d ), Figure 1], were prepared
using sodium perborate in acetic acid.4 X-ray analysis of
N-tosyl-4-(diacetoxyiodo)pyrrazole (2c) showed that the
structure adopted the same T-shaped structure as that
seen for (diacetoxyiodo)benzene.5 The thermal stability
of these novel trivalent iodine compounds was studied
in ClCD2CD2Cl in sealed tubes at about 120 °C by NMR.
The results showed that compounds 2d , 2b, and 2a
decomposed cleanly after 3 h, 7 h, and 21 h, respectively,
while 50% of the starting materials, compounds 1 and
2c, remained after 21 h. The main decomposition prod-
ucts were the corresponding iodoheteroaromatics, formed
through homolytic bond cleavage of the I-O bonds in
compounds 2. Then the reactivities for oxidation of
hydroquinones, the oxidative 1,2-rearrangement of ethyl
aryl ketones, iodination of aromatics, oxidation of diaryl
sulfides, the Hofmann rearrangement of amides, and
radical cyclization2k were examined, and the reactivities
were compared with that of (diacetoxyiodo)benzene, as
shown in Tables 1-6. In both oxidation of hydroquinones
and oxidative 1,2-rearrangement of ethyl aryl ketones,
compounds 2a -d showed the same reactivities as (di-
acetoxyiodo)benzene with high yields. However, in the
iodination of aromatics, compound 2d gave poor results,
though (diacetoxyiodo)benzene and compound 2c showed
good reactivity and compounds 2a and 2b showed moder-
ate reactivity. Probably, this result comes from the facts
that the ethyl acetate solution of compound 2d is not
homogeneous and that the oxidation potential of com-
pound 2d is high; in this case, the iodine was further
oxidized via an acylhypoiodite species, which is the real
iodination species of aromatics. As a result, iodination
of the aromatics did not occur effectively when using 2d .
On the other hand, in the oxidation of diphenyl sulfide
at 40 °C, compound 2d gave diphenyl sulfone mainly,
though other compounds, 1 and 2a -c, gave diphenyl
sulfoxide mainly. At room temperature (24 h), compound
2d also gave diphenyl sulfoxide alone in 96% yield.
Moreover, compounds 2a , 2c, and 2d gave ditolyl sulfone
in the oxidation of ditolyl sulfide, while compounds 1 and
2b gave ditolyl sulfoxide mainly under the same condi-
tions. In the Hofmann rearrangement of benzamide and
cinnamyl amide, the corresponding carbamates were
obtained in good yields with compounds 1, 2a , and 2b.
However, compound 2c showed the moderate reactivity,
and compound 2d gave poor results, because the metha-
nol solution of compound 2d were not homogeneous
again. In the radical cyclization of sulfonamides 14 via
the corresponding sulfonamidyl radical, in the presence
of iodine under the irradiation conditions with a tungsten
lamp, compounds 1 and 2a -c showed the same reactivi-
ties with high yields, though the ratio of compounds a
and b depends on compounds 1 or 2. Again the reactivity
of compound 2d decreased because of poor solubility of
compound 2d . In summary, compounds 2a -d have the
same reactivity as (diacetoxyiodo)benzene in the oxida-
P r ep a r a tion a n d Rea ctivities of Novel
(Dia cetoxyiod o)a r en es Bea r in g
Heter oa r om a tics
Hideo Togo,*,† Takahiro Nabana,† and
Kentaro Yamaguchi‡
Department of Chemistry, Faculty of Science, and
Chemical Analysis Center, Chiba University,
Yayoi-cho 1-33, Inage-ku, Chiba 263-8522 J apan
togo@scichem.s.chiba-u.ac.jp
Received August 4, 2000
Extensive study on hypervalent iodine compounds has
been carried out, and their uses in organic synthesis have
been gaining popularity.1 (Diacetoxyiodo)benzene has
been especially popular for oxidation of hydroquinones
and sulfides, R-hydroxylation of ketones, and oxidative
1,2-rearrangement of ketones, in organic synthesis.2
However, to our knowledge, the preparation and the
reactivities of (diacetoxyiodo)arenes containing hetero-
aromatics instead of a phenyl group have so far not been
studied, though the preparation of 3,5-dimethyl-4-[bis-
(trifluoroacetoxy)iodo]isoxazole and its reaction with
aromatics3a and the reactions of other organotrivalent
iodine compounds with heteroaromatics to form the
corresponding trivalent iodine compounds containing
heteroaromatics3 are known. Thus, we planned to pre-
pare (diacetoxyiodo)arenes by bonding heteroaromatics
to the iodine atom and compare the reactivities with that
of (diacetoxyiodo)benzene (1). Herein two types of (di-
acetoxyiodo)arenes, those containing π-excess heteroaro-
matics, such as thiophene, and π-deficient heteroaromat-
ics, such as pyrrazole [i.e., 2-(diacetoxyiodo)thiophene
† Department of Chemistry.
‡ Chemical Analysis Center.
(1) (a)Varvoglis A. Hypervalent Iodine in Organic Synthesis; Aca-
demic Press: San Diego, 1997. Recent reviews: (b) Ochiai, M. Rev.
Heteroatom Chem. 1989, 2, 92. (c) Moriarty, R. M.; Vaid, R. K.; Koser,
G. F. Synlett 1990, 365. (d) Moriarty, R. M.; Vaid, R. K. Synthesis 1990,
431. (e) Stang, P. J .; Angew. Chem., Int. Ed. Engl. 1992, 31, 274. (f)
Prakash, O.; Saini, N.; Sharma, P. K. Synlett 1994, 221. (g) Kitamura,
T. Yuki Gosei Kagaku Kyokaishi 1995, 53, 893. (h) Stang, P. J .;
Zhdankin, V. V. Chem. Rev. 1996, 96, 1123. (i) Umemoto, T. Chem.
Rev. 1996, 96, 1757. (j) Kita, Y.; Takada, T.; Tohma, H. Pure Appl.
Chem. 1996, 68, 627. (k) Togo, H.; Hoshina, Y.; Nogami, G.; Yokoyama,
M. Yuki Gosei Kagaku Kyokaishi 1997, 55, 90. (l) Varvoglis, A.
Tetrahedron 1997, 53, 1179. (m) Zhdankin, V. V. Rev. Heteroatom
Chem. 1997, 17, 133. (n) Kitamura, T.; Fujiwara, Y. Org. Prep. Proced.
Int. 1998, 29, 409. (o) Varvoglis, A.; Spyroudis, S. Synlett 1998, 221.
(p) Moriarty, R. M.; Prakash, O. Adv. Heterocycl. Chem. 1998, 69, 1.
(2) (a) Castrillon, J . P. A.; Szmant, H. H. J . Org. Chem. 1967, 32,
976. (b) Moriarty, R. M.; Hu, H. Tetrahedron Lett. 1981, 22, 2747. (c)
Moriarty, R. M.; Hu, H.; Gupta, S. C. Tetrahedron Lett. 1981, 22, 1283.
(d) Tamura, Y.; Shirouchi, Y.; Haruta, J . Synthesis 1984, 231. (e)
Tamura, Y.; Yakura, T.; Shirouchi, Y.; Haruta, J . Chem. Pharm. Bull.
1985, 33, 1097. (f) Pelter, A.; Elgendy, S. Tetrahedron Lett. 1988, 29,
677. (g) Singh, O. V. Tetrahedron Lett. 1990, 31, 3055. (h) Moriarty,
R. M.; Chany, C. J ., II; Vaid, R. K.; Prakash, O.; Tuladhar, S. M. J .
Org. Chem. 1993, 58, 2478. (i) Lee, J . C.; Cho, S. Y.; Cha, J . K.
Tetrahedron Lett. 1999, 40, 7675. (j) Togo, H.; Hoshina, Y.; Muraki,
T.; Nakayama, H.; Yokoyama, M. J . Org. Chem. 1999, 64, 5193. (k)
Togo, H.; Harada, Y.; Yokoyama, M. J . Org. Chem. 2000, 65, 926.
(3) (a) US Patent; Chem. Abstr. 1976, 84, 4936s. (b) Koser, G. K.;
Relenyi, A. G.; Kalos, A. N.; Rebrovic, L.; Wettach, R. H. J . Org. Chem.
1982, 47, 2487. (c) Carman, C. S.; Koser, G. F. J . Org. Chem. 1983,
48, 2534. (d) Margida, A. J .; Koser, G. F. J . Org. Chem. 1984, 49, 3643.
(e) Liu, J .-H.; Chan, H.-W.; Xue, F.; Wang, Q.-G.; Mak, T. C. W.; Wong,
H. N. C. J . Org. Chem. 1999, 64, 1630. (f) Carroll, M. A.; Pike, V. W.;
Widdowson, D. A. Tetrahedron Lett. 2000, 41, 5393.
(4) McKillop, A.; Kemp, D. Tetrahedron 1989, 45, 3299.
(5) Compound 2c: bond lengthes (Å) I-O 2.18, 2.12, I-C 2.06; bond
angles (deg) O-I-O 167.5, O-I-C 84.9, 82.7. Compound 1: bond
lengths (Å) I-O 2.14, 2.16, I-C 2.10; bond angles (deg) O-I-O 163.9,
O-I-C 81.8, 82.1.
10.1021/jo001186n CCC: $19.00 © 2000 American Chemical Society
Published on Web 11/01/2000

8392 J . Org. Chem., Vol. 65, No. 24, 2000
Notes
Ta ble 3. Iod in a tion of 1,3,5-Tr ia lk ylben zen es
yields (%)
1 or 2
R
8i
8ii
F igu r e 1. Novel (diacetoxyiodo)arenes bearing heteroaromat-
ics.
1
i-Pr
Me
i-Pr
Me
i-Pr
Me
i-Pr
Me
i-Pr
Me
90
0
0
98
0
21
0
0
0
21
0
0
Ta ble 1. Oxid a tion of Hyd r oqu in on es
2a
2b
2c
2d
50
73
33
96
80
74
0
52
1 or 2
R1
R2
yield (%)
Ta ble 4. Oxid a tion of Dia r yl Su lfid es
1
t-Bu
Me
t-Bu
Me
t-Bu
Me
t-Bu
Me
H
Me
H
Me
H
Me
H
Me
H
Me
99
92
96
97
99
79
99
89
93
99
2a
2b
2c
2d
t-Bu
Me
a
Reaction time was 70 min. for 3 (R1 ) Bu-t, R2 ) H). b Reaction
time was 50 min. for 3 (R1 ) R2 ) Me).
yields (%)
1 or 2
R
10
11
Ta ble 2. 1,2-Rea r r a n gem en t of Alk yl Ar yl Keton es
1
H
Me
H
Me
H
Me
H
Me
H
Me
93
95
86
9
82
55
85
7
0
4
14
84
0
37
15
85
74
95
2a
2b
2c
2d
1 or 2
R
yield (%)
1
Me
H
F
Me
H
F
Me
H
F
Me
H
F
92
87
81
85
79
73
97
94
88
95
91
88
96
90
93
26
0
2a
2b
2c
2d
Ta ble 5. Hofm a n n Rea r r a n gem en t
Me
H
F
1 or 2
yield (%)
tion of hydroquinones, oxidative 1,2-rearrangement of
ethyl aryl ketones, and radical cyclization, while com-
pound 2d has more powerful oxidizing ability toward
sulfides, though the iodination of aromatics and the
Hofmann rearrangement reaction with 2d did not work
because of poor solubility. Thus, these novel (diacetoxy-
iodo)arenes containing heteroromatics can be used as
synthetic reagents in organic synthesis similarly to
(diacetoxyiodo)benzene.
1
12i
12ii
12i
12ii
12i
12ii
12i
12ii
12i
12ii
87
80
87
85
92
98
82
43
30
0
2a
2b
2c
2d
downfield from TMS in δ units. J -Values are given in hertz. In
13C NMR spectra, p, s, t, and q means primary, secondary,
tertiary, and quaternary. Melting points were determined on an
electrothermal apparatus in open capillary tubes and are
uncorrected. Wakogel C-200 and Silica Gel 50 (Merck) were used
Exp er im en ta l Section
Gen er a l. 1H NMR spectra were recorded on 400 and 500 MHz
spectrometers and 13C NMR spectra were recorded on 100 and
125 MHz spectrometers. Chemical shifts are expressed in ppm

Notes
Ta ble 6. Ra d ica l Cycliza tion on to th e Ar om a tic Rin g
J . Org. Chem., Vol. 65, No. 24, 2000 8393
Gen er a l P r oced u r e for Iod in a tion . A mixture of aromatics
(0.5 mmol), (diacetoxyiodo)arene (0.9 mmol), and iodine (0.9
mmol) in dry ethyl acetate (5 mL) was stirred for 5 h at 60 °C
under dark conditions and an argon atmosphere. The resulting
solution was quenched with aq Na2SO3, and the solution was
extracted with chloroform twice. The extract was dried over
Na2SO4 and evaporated under reduced pressure; the residual
oil was purified by preparative TLC on silica gel using hexane.
Gen er a l P r oced u r e for Oxid a tion of Su lfid e. Sulfide (1
mmol) was added to (diacetoxyiodo)arene (2.0 mmol), in chlo-
roform (5 mL) containing 1% of water. The mixture was stirred
for 72 h at 40 °C under an argon atmosphere. Then the reaction
mixture was evaporated, and the residue was purified by
preparative TLC on silica gel (eluent: hexane/ethyl acetate )
5/1) to give pure sulfoxide and sulfone.
Gen er a l P r oced u r e for th e Hofm a n n Rea r r a n gem en t.
Amide (1 mmol) was added to the homogeneous solution of
methanol (50 mL) and KOH (2.5 mmol), and subsequently
(diacetoxyiodo)arene (1 mmol) was added to the solution. The
mixture was stirred for 15 min at 0 °C and then for 1 h at room
temperature under argon atmosphere. Then, the reaction mix-
ture was evaporated, and the residue was treated with pTLC
on silica gel (eluent: hexane: ethyl acetate ) 3:1) to give
carbamate ester.
1 or 2
R
yields (%) of 15 (a /b)
1
H
CH3
H
CH3
H
CH3
H
CH3
H
CH3
75 (19/66)
92 (0/92)
87 (61/26)
95 (25/70)
88 (42/46)
86 (0/86)
94 (94/0)
91 (34/57)
67 (67/0)
71 (59/12)
2a
2b
2c
2d
for column chromatography, Kieselgel 60 F254 (Merck) was used
for TLC, and Wakogel B-5F was used for pTLC.
Gen er a l P r oced u r e for th e P r ep a r a tion of Com p ou n d s
2. To the solution of iodoarene (10 mmol) in acetic acid (100 mL)
was added sodium perborate tetrahydrate (100 mmol) over 0.5
h. Then the solution was heated at 50-60 °C for 8-24 h under
argon atmosphere, until the starting iodoarene disappeared.
After the reaction, the solvent was removed. Water was added
to the residue, and the mixture was extracted with chloroform
for three times (30 mL × 3). The combined organic layer was
dried over Na2SO4. After the filtration, the solvent was removed,
and the residue was recrystallized from chloroform and hexane.
2-(Dia cetoxyiod o)th iop h en e 2a : mp 120-122 °C (decomp);
Gen er a l P r oced u r e for th e Ra d ica l Cycliza tion . (Diac-
etoxyiodo)arene (0.8 mmol) and iodine (0.5 mmol) were added
to a solution of amide (0.5 mmol) in 1,2-dichloroethane (5 mL).
The mixture was irradiated with a tungsten lamp (500 W) at
20-30 °C for 2 h under agon atmosphere. After the reaction,
the mixture was poured into a saturated aqueous sodium sulfite
solution and extracted with chloroform three times. The organic
layer was dried over sodium sulfate. After removal of the solvent,
the residue was treated with pTLC on silica gel (eluent: hexane:
ethyl acetate:chloroform ) 6:3:1) to give the cyclized product.
2,3,5-Tr im eth yl-1,4-ben zoqu in on e: mp 28-29 °C (lit. mp
29 °C6) IR (KBr) 3060, 2880, 1650, 1380 cm-1; 1H NMR (CDCl3)
δ ) 2.01(3H, q, J ) 1.1 Hz), 2.03 (3H, q, J ) 1.1 Hz), 2.04 (3H,
d, J ) 1.7 Hz), 6.56 (1H, q, J ) 1.7 Hz).
1
IR (KBr) 3100, 1640, 1560, 1270, 1010, 710, and 500 cm-1; H
NMR (CDCl3) δ ) 2.01 (6H, S), 7.14 (1H, dd, J ) 5.4 and 3.9
Hz), 7.64 (1H, dd, J ) 5.4 and 1.2 Hz), 7.78 (1H, dd, J ) 3.9 and
1.2 Hz); 13C NMR (CDCl3) δ ) 20.29 (p), 106.22 (q), 128.57 (t),
134.81 (t), 139.01 (t), 176.95 (q).
2,6-Di-ter t-bu tyl-1,4-ben zoqu in on e: mp 146-147 °C (lit.
mp 150-151 °C6); IR (KBr) 2870, 1650, 1360 cm-1
(CDCl3) δ ) 1.27 (18H, s), 6.48 (2H, s).
;
1H NMR
3-(Dia cetoxyiod o)th iop h en e 2b: mp 168-178 °C (decomp);
1
IR (KBr) 3100, 1640, 1590, 1290, 1010, 700, and 500 cm-1; H
Meth yl 2-p h en ylp r op a n oa te: bp 65 °C/2.5 mmHg (lit. bp
104-105 °C/18 mmHg2e); IR (neat) 2980, 1740, 1600, 1495, 1455,
1210, 1165 cm-1; 1H NMR (CDCl3) δ ) 1.50 (3H, d, J ) 7.2 Hz,
3.66 (3H, s), 3.73 (1H, q, J ) 7.2 Hz), 7.24-7.35 (5H, m).
Meth yl 2-(4-flu or op h en yl)p r op a n oa te: oil; IR (neat) 2980,
NMR (CDCl3) δ ) 2.02 (6H, s), 7.52 (1H, dd, J ) 5.2 and 1.3
Hz), 7.48 (1H, dd, J ) 5.2 and 3.0 Hz), 8.05 (1H, dd, J ) 3.0 and
1.3 Hz); 13C NMR (CDCl3) δ ) 20.29 (p), 106.42 (q), 128.14 (t),
133.58 (t), 133.58 (t), 176.53 (q). Elem. Anal. Found: C, 29.04;
H, 2.85%. Calcd for C8H9IO4S: C, 29.28; H, 2.76%.
2960, 1740, 1320 cm-1 1H NMR (CDCl3) δ) 1.48 (3H, d, J )
;
N-Tosyl-4-(d ia cetoxyiod o)p yr r a zole 2c: mp 183-193 °C
(decomp); IR (KBr) 3050, 1640, 1590, 1270, 1160, 1050, 930, and
7.2 Hz), 3.66 (3H, s), 3.71 (1H, q, J ) 7.2 Hz), 7.00 (2H, tt, J )
8.7 and 2.1 Hz), 7.26 (2H, ddt, J ) 8.7, 5.3 and 2.1 Hz); HRMS
(EI) found m/z 182.0740, calcd for C10H11FO2 182.0743.
Meth yl 2-(4-Meth ylp h en yl)p r op a n oa te: oil; IR (neat) 2955,
500 cm-1 1H NMR (CDCl3) δ ) 2.05 (6H, s), 2.46 (3H, s),7.40
;
(2H, d, J ) 8.2 Hz), 7.97 (1H, s), 7.97 (2H, d, J ) 8.2 Hz), 8.50
(1H, s); 13C NMR (CDCl3) δ ) 20.24 (p), 21.79 (p). 90.56 (q),
128.77 (t), 130.33 (t), 132.65 (q), 135.08 (t), 145.96 (t), 147.09
(q), 176.93 (q). Elem. Anal. Found: C, 35.59; H, 3.22; N, 5.90%.
Calcd for C14H15IN2O6S: C, 36.06; H, 3.24; N, 6.01%.
1740, 1515, 1460, 1205, 1165 cm-1 1H NMR (CDCl3) δ) 1.48
;
(3H, d, J ) 7.2 Hz), 2.33 (3H, s), 3.65 (3H, s), 3.69 (1H, q, J )
7.2 Hz), 7.13 (2H, d, J ) 8.1 Hz), 7.19 (2H, d, J ) 8.1 Hz); HRMS
(EI) found m/z 178.0997, calcd for C11H14O2 178.0994.
1-Iod o-2,4,6-tr iisop r op ylben zen e: oil; bp ) 115 °C/2.5
mmHg (lit. bp 173-175 °C/28 mmHg7a); IR (neat) 2950, 1565,
1460, and 740 cm-1;1H NMR (CDCl3) δ ) 1.24 (12H, d, J ) 6.8
Hz), 1.25 (6H, d, J ) 7.0 Hz), 2.87 (1H, sept, J ) 7.0 Hz), 3.39
(2H, sept, J ) 7.0 Hz), 6.95 (2H, s); 13C NMR (CDCl3) δ ) 23.43
(p), 23.98 (p), 33.88 (t,), 39.26 (t), 105.71 (q), 122.07, (t), 148.83
(q), 150.77 (q); MS (EI) Found: M+ ) 330. Calcd for C15H22I: M
) 330.
N-Tr iflu or om et h a n esu lfon yl-4-(d ia cet oxyiod o)p yr r a -
zole 2d : mp 122-124 °C (decomp); IR (KBr) 3130, 1640, 1560,
1415, 1300, 1190, 1160, 1040, 730, and 500 cm-1;1H NMR
(CDCl3) δ ) 2.03 (6H, s), 8.06 (2H, s); 13C NMR (CDCl3) δ )
20.33 (p), 89.17 (q), 138.74 (t), 176.78 (q).
Gen er a l P r oced u r e for Oxid a tion of Hyd r oqu in on e.
Hydroquinone (1 mmol) was added to (diacetoxyiodo)arene (1.3
mmol) in methanol (5 mL). The mixture was stirred for 2 h at
room temperature under an argon atmosphere. Then, the
reaction mixture was evaporated, and the residue was purified
by preparative TLC on silica gel (eluent: hexane/ethyl acetate
) 5/1) to give a pure quinone.
Gen er a l P r oced u r e for 1,2-Rea r r a n gem en t of Alk yl Ar yl
Keton es. Sulfuric acid (2 mmol) was added dropwise to a
solution of (diacetoxyiodo)arene (1.2 mmol) and propiophenone
(1.0 mmol) in 3 mL of trimethyl orthoformate at 0 °C. The
reaction mixture was stirred for 2 h at 60 °C under an argon
atmosphere. Then the reaction mixture was poured into water
and extracted with chloroform twice. The combined organic layer
was dried over Na2SO4. After the filtration, the solvent was
evaporated under reduced pressure, and the residue was purified
by preparative TLC on silica gel.
Diiod om esitylen e: mp 79.0-80.3 °C (lit. mp 82 °C 7b); IR
(KBr) 2975, 1440, 1375, and 860 cm-1 1H NMR (CDCl3) δ )
;
2.42 (6H, s), 2.92 (3H, s), 7.00 (1H, s); MS (EI) Found: M+
)
372. Calcd for C9H10I2: M ) 372.
Iod om esitylen e: mp 30-31 °C (lit. mp 30.5-31 °C 7a); IR
(KBr) 2975, 1440, 1373, and 860 cm-1 1H NMR (CDCl3) δ )
;
2.24 (3H, s), 2.42 (6H, s), 6.89 (2H, s); MS (EI) Found: M+
)
246. Calcd for C9H11I: M ) 246.
(6) a) Mckillop, A.; Swann, B. P.; Taylor, E. C. Tetrahedron 1970,
26, 4031. (b) Pelter, A.; Elgendy, S. Tetrahedron Lett. 1988, 29, 677.
(7) (a) Suzuki, H.; Sugiyama, T.; Goto, R. Bull. Chem. Soc. J pn.
1964, 37, 1858. (b) Kajigaeshi, S.; Kakinami, T.; Morikawa, M.; Tanaka,
T.; Fujisaki, S.; Okamoto, T. Bull. Chem. Soc. J pn. 1989, 62, 439.

8394 J . Org. Chem., Vol. 65, No. 24, 2000
Notes
Di(p-tolyl) su lfoxid e: mp 91 °C (lit. mp 92 °C8); d i(p-tolyl)
su lfon e: mp 156 °C (lit. mp 158 °C 8); d ip h en yl su lfoxid e:
mp 70 °C (lit. mp 70 °C8); d ip h en yl su lfon e: mp 126 °C (lit.
mp 127 °C8).
(3H, s), 3.30 (2H, t, J ) 6.8 Hz), 3.38 (2H, t, J ) 6.8 Hz), 6.82
(1H, s), 7.57 (1H, s); 13C NMR (CDCl3) δ ) 26.95 (s), 27.89 (p),
31.86 (p), 45.31 (s), 93.21 (q), 118.45 (t), 122.07 (q), 139.06 (t),
141.07 (q), 141.31 (q); MS (EI) M+ 337. Anal. Calcd for C10H12
-
INO2S: C, 35.62; H, 3.59; N, 4.15. Found: C, 35.67; H, 3.45; N,
3.99.
Meth yl N-p h en ylca r ba m a te: mp 44-45 °C (lit. mp 47-48
°C9); m eth yl (E)-N-(2-p h en yleth en yl)ca r ba m a te: mp 115-
116 °C (lit. mp119 °C9).
N-Met h yl-7-m et h yl-3,4-d ih yd r o-2,1-b en zot h ia zin e 2,2-
d ioxid e: mp 79.0-81.0 °C; IR (KBr) 3000, 2940, 1620, 1570,
N-Meth yl-3,4-d ih yd r o-2,1-ben zoth ia zin e 2,2-d ioxid e: mp
77.0-79.0 °C; IR (KBr) 2980, 2940, 1580, 1490, 1330, 1170 cm-1
;
1330, 1160 cm-1 1H NMR (CDCl3) δ ) 2.34 (3H, s), 3.29 (3H,
;
1H NMR (CDCl3) δ ) 3.30 (3H, s), 3.33 (2H, t, J ) 6.9 Hz), 3.44
(2H, t, J ) 6.9 Hz), 6.96 (1H, dd, J ) 8.0, 1.0 Hz), 7.05 (1H, t,d
s), 3.29-3.34 (2H, m), 3.40 (2H, t, J ) 7.3 Hz), 6.77 (1H, s), 6.86
(1H, m), 7.04 (1H, d, J ) 7.7 Hz); 13C NMR (CDCl3) δ ) 26.95
(s), 27.89 (p), 31.86 (p), 45.31 (s), 93.21 (q), 118.45 (t), 122.07
(q), 139.06 (t), 141.07 (q), 141.31 (q); HRMS (EI) m/z 211.0674,
calcd for C10H13NO2S 211.0667.
J ) 7.6, 1.0 Hz), 7.16 (1H, dd, J ) 7.6, 1.2 Hz), 7.27 (1H, m); 13
C
NMR (CDCl3) δ ) 27.90 (s), 31.97(p), 45.55 (s), 117.47 (t), 122.82
(q), 123.14 (t), 127.88 (t), 129.30 (t), 141.14 (q); MS (EI) M+ 197.
Anal. Calcd for C9H11NO2S: C, 54.80; H, 5.62; N, 7.10. Found:
C, 54.74; H, 5.52; N, 7.07.
Ack n ow led gm en t. Financial support from a Grant-
in-Aid for Scientific Research (No. 08554031) from the
Ministry of Education, Science, Culture of J apan, Fut-
aba Electronics Memorial Foundation, and The Re-
search Center of Taiho Phamaceutical Co. are gratefully
acknowledged. We thank Ms. Ritsuko Hara for the
measurements of MS(EI) and Dr. Hiroko Seki and Ms.
Yukiko Hiramoto for elemental analysis in the Chemical
Analysis Center of Chiba University.
N-Met h yl-6-iod o-3,4-d ih yd r o-2,1-b en zot h ia zin e 2,2-d i-
oxid e: mp 139.0-141.0 °C; IR (KBr) 2940, 1590, 1560, 1320,
1
1100 cm-1; H NMR (CDCl3) δ ) 3.26 (3H, s), 3.32 (2H, t, J )
7.1 Hz), 3.40 (2H, t, J ) 7.1 Hz), 6.70 (1H, d, J ) 8.8 Hz), 7.49
(1H, d, J ) 2.0 Hz), 7.55 (1H, dd, J ) 8.8, 2.0 Hz); 13C NMR
(CDCl3) δ ) 27.51 (s), 31.74 (p), 45.27 (s), 86.24 (q), 119.16 (t),
125.03 (q), 136.73 (t), 137.89 (t), 141.06 (q); MS (EI) M+ 323.
Anal. Calcd for C9H10INO2S: C, 33.45; H, 3.12; N, 4.33. Found:
C, 33.55; H, 3.06; N, 4.27.
N-Met h yl-6-iod o-7-m et h yl-3,4-d ih yd r o-2,1-b en zot h ia z-
in e 2,2-d ioxid e: mp 138.0-139.0 °C; IR (KBr) 3000, 2940, 1600,
1
1
1550, 1330, 1160 cm-1; H NMR (CDCl3) δ ) 2.41 (3H, s), 3.27
Su p p or tin g In for m a tion Ava ila ble: Copies of H NMR
spectra for compounds 2a -d , 4, 6, 8, 10, 11, 13, and 15, and
X-ray data of compounds 1 and 2c. This material is available
free of charge via the Internet at http://pubs.acs.org.
(8) (a) Mckillop, A.; Swann, B. P.; Taylor, E. C. Tetrahedron 1970,
26, 4031. (b) Pelter, A.; Elgendy, S. Tetrahedron Lett. 1988, 29, 677.
(9) Rheinbold, H.; Giesbecht, E. J . Am. Chem. Soc. 1946, 68, 973.
(10) Moriarty, R. M.; Chany, C. J ., II; Vaid, R. K.; Prakash, O.;
Tuladhar, S. M. J . Org. Chem. 1993, 58, 2478.
J O001186N