1052 Bull. Chem. Soc. Jpn., 76, No. 5 (2003)
Five-Membered Trichalcogenaheterocycles
Anal. Calcd for C10H12O2S3: C, 46.13; H, 4.64%. Found: C,
46.29; H, 4.61%.
7-Isopropyl-4-methoxy-1,2,3-benzodithiaselenole 2-Oxide
for C10H12OS2Se: C, 41.23; H, 4.15%. Found: C, 41.52; H,
4.28%.
4-Isopropyl-7-methoxy-1,2,3-benzodithiaselenole (4c). Or-
ange oil; 1H NMR (400 MHz) ꢁ 1.23 (d, J ¼ 6:8 Hz, 6H,
CH(CH3)2), 2.77 (sept, J ¼ 6:8 Hz, 1H, CH(CH3)2), 3.84 (s,
3H, OCH3), 6.70 (d, J ¼ 8:4 Hz, 1H, ArH), 7.01 (d, J ¼ 8:4
Hz, 1H, ArH); 13C NMR (101 MHz) ꢁ 23.5, 38.0, 56.2, 110.8,
125.3, 130.1, 140.9, 154.7; 77Se NMR (76 MHz) ꢁ 624.1; IR (neat)
2960, 2835, 1579, 1470, 1433, 1278, 1090, 1031, 804 cmꢂ1; MS
(70 eV) m=z 292 (Mþ); Anal. Calcd for C10H12OS2Se: C, 41.23;
H, 4.15%. Found: C, 41.52; H, 4.12%.
ꢁ
1
(3b). Orange crystals; mp 70.5–71.0 C; H NMR (400 MHz) ꢁ
1.23 (d, J ¼ 6:8 Hz, 3H, CH(CH3)2), 1.34 (d, J ¼ 6:8 Hz, 3H,
CH(CH3)2), 3.09 (sept, J ¼ 6:8 Hz, 1H, CH(CH3)2), 3.90 (s,
3H, OCH3), 6.87 (d, J ¼ 8:3 Hz, 1H, ArH), 7.29 (d, J ¼ 8:3
Hz, 1H, ArH); 13C NMR (101 MHz) ꢁ 22.8, 23.6, 34.9, 56.3,
109.6, 125.3, 126.3, 139.0, 154.5; 77Se NMR (76 MHz) ꢁ
1152.3; IR (neat) 2961, 1581, 1557, 1464, 1265, 1222, 1115,
1040, 907, 463 cmꢂ1; MS (70 eV) m=z 308 (Mþ); Anal. Calcd
for C10H12O2S2Se: C, 39.09; H, 3.94%. Found: C, 39.18; H,
3.98%.
4-Isopropyl-7-methoxy-2,1,3-benzothiadiselenole (4d). Red
1
oil; H NMR (400 MHz) ꢁ 1.22 (d, J ¼ 6:8 Hz, 6H, CH(CH3)2),
4-Isopropyl-7-methoxy-1,2,3-benzodithiaselenole 2-Oxide
(3c). Yellow oil; 1H NMR (400 MHz) ꢁ 1.23 (d, J ¼ 6:8 Hz, 3H,
CH(CH3)2), 1.35 (d, J ¼ 6:8 Hz, 3H, CH(CH3)2), 2.77 (sept, J ¼
6:8 Hz, 1H, CH(CH3)2), 3.90 (s, 3H, OCH3), 6.90 (d, J ¼ 8:6 Hz,
1H, ArH), 7.25 (d, J ¼ 8:6 Hz, 1H, ArH); 13C NMR (101 MHz) ꢁ
22.9, 23.7, 37.9, 56.3, 110.2, 125.7, 127.4, 137.9, 139.1, 154.7;
77Se NMR (76 MHz) ꢁ 1149.0; IR (neat) 2960, 1578, 1461,
1430, 1286, 1105, 1030, 807 cmꢂ1; MS (70 eV) m=z 308 (Mþ);
Anal. Calcd for C10H12O2S2Se: C, 39.09; H, 3.94%. Found: C,
39.42; H, 3.91%.
2.83 (sept, J ¼ 6:8 Hz, 1H, CH(CH3)2), 3.82 (s, 3H, OCH3),
6.71 (d, J ¼ 8:4 Hz, 1H, ArH), 7.06 (d, J ¼ 8:4 Hz, 1H, ArH);
13C NMR (101 MHz) ꢁ 23.6, 38.0, 56.2, 110.6, 125.7, 129.0,
140.2, 141.7, 155.7; 77Se NMR (76 MHz) ꢁ 655.9, 645.4; IR (neat)
2959, 1578, 1464, 1432, 1278, 1078, 1030, 804 cmꢂ1; MS (70 eV)
m=z 340 (Mþ); Anal. Calcd for C10H12OSSe2: C, 35.52; H, 3.58%.
Found: C, 35.67; H, 3.34%.
General Procedure for the Synthesis of 4-Isopropyl-7-meth-
oxy-1,2,3-benzotrichalcogenoles 4e–h. To a solution of 4-iso-
propyl-7-methoxy-2,2-dimethyl-1,3,2-benzodithiastannole
(181 mg, 0.50 mmol) in THF (10 mL) was added seleninyl chlor-
(1a)
4-Isopropyl-7-methoxy-2,1,3-benzothiadiselenole 2-Oxide
ꢁ
1
ꢁ
(3d). Orange crystals; mp 63.0–64.0 C; H NMR (400 MHz) ꢁ
1.22 (d, J ¼ 6:8 Hz, 3H, CH(CH3)2), 1.35 (d, J ¼ 6:8 Hz, 3H,
CH(CH3)2), 2.85 (sept, J ¼ 6:8 Hz, 1H, CH(CH3)2), 3.89 (s,
3H, OCH3), 6.91 (d, J ¼ 8:6 Hz, 1H, ArH), 7.28 (d, J ¼ 8:6
Hz, 1H, ArH); 13C NMR (101 MHz) ꢁ 155.4, 141.1, 140.4,
129.3, 126.1, 110.0, 56.3, 37.9, 23.9, 23.0; 77Se NMR (76 MHz)
ꢁ 1159.3, 1156.4; IR (neat) 2960, 1578, 1461, 1430, 1286,
1264, 1105, 1030, 807 cmꢂ1; MS (70 eV) m=z 356 (Mþ); Anal.
Calcd for C10H12O2SSe2: C, 33.91; H, 3.41%. Found: C, 34.24;
H, 3.37%.
ide (0.042 mL, 0.60 mmol) in THF (6 mL) at ꢂ78 C. After 40
min at ꢂ78 ꢁC, the reaction mixture was treated with trimethylsi-
lyl trifluꢁoromethanesulfonate (0.11 ꢁmL, 0.6 mmol) in THF (2 mL)
at ꢂ78 C. After 30 min at ꢂ78 C, 0.1 M samarium(b) iodide
THF solution (12.0 mL, 1.2 mmol) was added at ꢂ78 ꢁC. The re-
sulting solution was stirred for 45 min at ꢂ78 ꢁC, then was stirred
for 90 min at room temperature, and then poured into water. The
organic layer was extracted with dichloromethane, washed with
sodium chloride solution, and dried over anhydrous magnesium
sulfate. The solution was concentrated in vacuo and purified by
column chromatography on silica gel with hexane as an eluent
to give 119 mg (0.41 mmol, 82%) of 4-isopropyl-7-methoxy-
1,3,2-benzodithiaselenole (4e) as a reddish brown oil: 1H NMR
(400 MHz) ꢁ 1.22 (d, J ¼ 6:8 Hz, 6H, CH(CH3)2), 3.09 (sept, J ¼
6:8 Hz, 1H, CH(CH3)2), 3.84 (s, 3H, OCH3), 6.60 (d, J ¼ 8:5 Hz,
1H, ArH), 6.93 (d, J ¼ 8:5 Hz, 1H, ArH); 13C NMR (101 MHz) ꢁ
23.2, 34.7, 56.1, 110.5, 125.2, 129.9, 138.5, 142.8, 154.7;
77Se NMR (76 MHz) ꢁ 701.3; IR (neat) 2963, 1712, 1577, 1468,
1432, 1275, 1039, 903 cmꢂ1; MS (70 eV) m=z 292 (Mþ); Anal.
Calcd for C10H12OS2Se: C, 41.23; H, 4.15%. Found: C, 41.03;
H, 4.16%.
General Procedure for the Synthesis of 4-Isopropyl-7-meth-
oxy-1,2,3-benzotrichalcogenoles 4a–d. To a solution of 1,2,3-
benzotrithiole 2-oxide 3a (87 mg, 0.33 mmol) and sodium iodide
(253 mg, 1.67 mmol) in THF (30 mL) and H2O (3.1 mL) was
ꢁ
added a 70% perchloric acid solution (4.0 mL) at 0 C. After 6
h at room temperature, the reaction mixture was neutralized with
aqueous sodium hydrogencarbonate solution and extracted with
dichloromethane. The organic layer was washed with aqueous so-
dium hydrogensulfite solution and dried over anhydrous magne-
sium sulfate. The solution was concentrated in vacuo and purified
by column chromatography on silica gel with tetrachloromethane
as an eluent to give 78 mg (0.32 mmol, 97%) of 1,2,3-benzo-
7-Isopropyl-4-methoxy-1,2,3-benzothiadiselenole (4f).
1
trithiole 4a as an orange oil: H NMR (400 MHz) ꢁ 1.23 (d, J ¼
Brown oil; 1H NMR (400 MHz) ꢁ 1.22 (d, J ¼ 6:8 Hz, 6H,
CH(CH3)2), 3.15 (sept, J ¼ 6:8 Hz, 1H, CH(CH3)2), 3.83 (s,
3H, OCH3), 6.61 (d, J ¼ 8:4 Hz, 1H, ArH), 7.00 (d, J ¼ 8:4
Hz, 1H, ArH); 13C NMR (101 MHz) ꢁ 23.4, 34.9, 56.1, 110.4,
125.7, 128.0, 139.4, 143.6, 155.5; 77Se NMR (76 MHz) ꢁ 568.9,
507.6 (JSe-Se ¼ 311 Hz); IR (neat) 2958, 1579, 1463, 1432,
1274, 1039, 802 cmꢂ1; MS (70 eV) m=z 340 (Mþ); HRMS m=z
Calcd for C10H12OSSe2: 339.8939. Found: 339.8950.
6:9 Hz, 6H, CH(CH3)2), 2.95 (sept, J ¼ 6:9 Hz, 1H, CH(CH3)2),
3.84 (s, 3H, OCH3), 6.65 (d, J ¼ 8:4 Hz, 1H, ArH), 6.97 (d, J ¼
8:4 Hz, 1H, ArH); 13C NMR (101 MHz) ꢁ 23.1, 35.0, 56.1, 110.4,
125.3, 137.5, 141.7, 153.9; IR (neat) 2960, 2836, 1582, 1473,
1435, 1279, 1236, 1094, 1039, 803, 580 cmꢂ1; MS (70 eV) m=z
244 (Mþ); Anal. Calcd for C10H12OS3: C, 49.15; H, 4.95%.
Found: C, 49.51; H, 4.97%.
7-Isopropyl-4-methoxy-1,2,3-benzodithiaselenole (4b).
4-Isopropyl-7-methoxy-1,2,3-benzothiadiselenole (4g).
Reddish brown oil; 1H NMR (400 MHz) ꢁ 1.22 (d, J ¼ 6:8 Hz,
6H, CH(CH3)2), 3.02 (sept, J ¼ 6:8 Hz, 1H, CH(CH3)2), 3.83
(s, 3H, OCH3), 6.66 (d, J ¼ 8:4 Hz, 1H, ArH), 7.03 (d, J ¼ 8:4
Hz, 1H, ArH); 13C NMR (101 MHz) ꢁ 23.3, 35.1, 56.1, 110.4,
125.7, 127.2, 138.3, 142.7, 155.0; 77Se NMR (76 MHz) ꢁ 633.6;
IR (neat) 2959, 2835, 1582, 1469, 1434, 1278, 1231, 1181,
1082, 1038, 803 cmꢂ1; MS (70 eV) m=z 292 (Mþ); Anal. Calcd
Reddish-brown oil; 1H NMR (400 MHz) ꢁ 1.23 (d, J ¼ 6:8 Hz,
6H, CH(CH3)2), 2.90 (sept, J ¼ 6:8 Hz, 1H, CH(CH3)2), 3.84
(s, 3H, OCH3), 6.66 (d, J ¼ 8:4 Hz, 1H, ArH), 6.97 (d, J ¼ 8:4
Hz, 1H, ArH); 13C NMR (101 MHz) ꢁ 23.5, 37.8, 56.2, 110.8,
125.2, 131.4, 140.0, 141.4, 155.6; 77Se NMR (76 MHz) ꢁ 581.8,
501.9 (JSe-Se ¼ 279 Hz); IR (neat) 2958, 1575, 1464, 1431,
1274, 1087, 1030, 804 cmꢂ1; MS (70 eV) m=z 340 (Mþ); HRMS