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12. (a) Zade, S. S.; Singh, H. B.; Butcher, R. J. Angew. Chem. 2004, 116, 4613. Angew.
Chem. Int. Ed. 2004, 43, 4513; (b) Zade, S. S.; Panda, S.; Singh, H. B.; Sunoj, R. B.;
Butcher, R. J. J. Org. Chem. 2005, 70, 3693.
13. (a) Singh, V. P.; Singh, H. B.; Butcher, R. J. Eur. J. Inorg. Chem. 2010, 637; (b)
Singh, V. P.; Singh, H. B.; Butcher, R. J. Chem. Commun. 2011, 7221; (c) Singh, V.
P.; Singh, H. B.; Butcher, R. J. Chem. Asian J. 2011, 6, 1431.
14. Osjda, M.; Kloc, K.; Mlochowski, J.; Piasecki, E.; Rybka, K. Pol. J. Chem. 2001, 75,
823.
15. Bhabak, K. P.; Mugesh, G. Chem. Eur. J. 2007, 13, 4594.
16. Selvakumar, K.; Singh, H. B.; Butcher, R. J. Chem. Eur. J. 2010, 16, 10576.
17. Selvakumar, K.; Singh, H. B. 1th Electronic Symposium on Selenium Chemistry,
18. Synthesis of 6: To a stirred solution of diselenide 5 (0.33 g, 0.50 mmol) in CHCl3
30 min at room temperature, the solvent was evaporated to give a pale yellow
precipitate, which was filtered and washed with ethyl acetate/petroleum ether
mixture (1:2). Yield (0.52 g, 56%); 1H NMR (CDCl3) d 11.97 (s, br, 1H), 8.23 (s,
br, 2H), 4.41 (t, br, 2H), 4.05 (s, 3H), 3.44 (t, br, 2H), 2.92 (s, 6H), 1.39(s, 9H); 13
C
NMR (CDCl3) 168.1, 167.6, 151.4, 139.8, 130.2, 129.7, 127.9, 123.7, 56.1, 53.7,
43.5, 39.4, 35.1, 31.5; 77Se NMR (CDCl3) d 908; FT-IR (KBr, cmꢂ1) 2950, 2716,
1679, 1638, 1448, 1364, 1344, 1287, 1257, 1056, 781, 588; ES-MS: m/z Calcd
for
C
17H25N2O3Se: 464. Found: 385 [MꢂBr]+(100%); Anal. Calcd for
C17H25N2O3Se: C, 43.98; H, 5.43; N, 6.03. Found: C, 44.03; H, 5.35; 6.23.
22. Synthesis of 10: To a stirred solution of diselenide 5 (0.33 g, 0.50 mmol) in
CHCl3 (25 mL) was added bromine (0.09 g, 0.58 mmol) at room temperature.
After the addition of bromine, the reaction mixture was stirred at room
temperature for 2 h. To this, a CHCl3 (10 mL) solution containing glycine
methyl ester hydrochloride (0.13 g, 1.0 mmol) and triethyl amine (0.14 mL,
1.0 mmol) was added rapidly. The stirring was continued for additional 30 min.
The reaction mixture was poured into water and the organic layer separated.
The organic layer was washed with 1 N HCl followed by twice with water. It
was dried over sodium sulfate and evaporated to give an off-white solid. The
crude solid was recrystallized from ethyl acetate and petroleum ether to afford
10 as a colorless solid. Yield (0.23 g, 60%); mp 215–220 °C (decomposes); 1H
NMR (CDCl3) d 8.32 (d, J = 2.0 Hz, 1H), 8.27 (d, J = 1.9 Hz, 1H), 4.60 (s, 2H), 4.13
(s, 3H), 3.79 (s, 3H), 1.49(s, 9H); 13C NMR (CDCl3) d 169.5, 168.3, 167.4, 151.1,
140.2, 130.3, 130.1, 128.1, 123.5, 53.6, 52.7, 45.4, 35.2, 31.6; 77Se NMR (CDCl3)
d 914; FT-IR (KBr, cmꢂ1) 2952, 1742, 1673, 1648, 1445, 1355, 1272, 1260, 1334,
1304, 1034, 1017, 781, 590; ES-MS: m/z Calcd for C17H25N2O3Se: 385. Found:
409 [M+Na]+(17%), 386 [M+H]+(100%); Anal. Calcd for C17H25N2O3Se: C, 50.01;
H, 4.98; N, 3.64. Found: C, 49.59; H, 5.13; N, 2.61.
(25 mL), was added bromine (30 lL, 0.09 g, 0.58 mmol) at room temperature.
The reaction mixture was stirred at room temperature for 2 h. To the above
was added Et3N (0.14 mL, 1.0 mmol) and ethylenediamine (0.03 mL,
0.51 mmol) in CHCl3 (5.0 mL). After the addition, the reaction was stirred at
room temperature for 30 min. The reaction mixture was poured into water and
was washed both with 1 N HCl, 5% aqueous NaHCO3 and water (twice). The
organic layer dried over sodium sulfate was evaporated to give a pale yellow
solid. It was recrystallized from ethyl acetate and petroleum ether (1:2)
mixture. Yield (0.19 g, 58%): mp >260 °C; 1H NMR (CDCl3) d 8.31 (d, J = 2.0 Hz,
2H). 8.24 (d, J = 2.0 Hz, 2H), 4.10 (s, 4H), 4.01 (s, 6H), 1.42 (s, 18H); 13C NMR
(CDCl3) d 168.2, 167.3, 151.0, 139.8, 130.2, 130.0, 128.8, 123.6, 53.5, 44.4, 35.2,
31.6; 77Se NMR (CDCl3) d 907; FT-IR (KBr, cmꢂ1) 2960, 1671, 1652, 1448, 1341,
1257, 1042, 781, 762, 589; ES-MS: m/z Calcd for C28H32N2O6Se2: 652. Found:
653 [M+H]+(100%); Anal. Calcd for C28H32N2O6Se2: C, 51.70; H, 4.96; N, 4.31.
Found: C, 49.56; H, 5.05; N, 4.40.
23. Synthesis of 11: Compound 11 was synthesized following the procedure
described for compound 8 using diselenide 5 (0.66 g, 1.0 mmol), Br2 (0.19 g,
1.2 mmol), CHCl3 (25 mL) and Et3N (0.28 mL, 2.0 mmol) and 2-
chloroethylamine (0.23 g, 2.0 mmol) in MeOH/CHCl3 (0.5 mL:4.5 mL). Yield
(0.46 g, 61%); 1H NMR(CDCl3) d 8.32 (d, J = 2.0 Hz, 1H), 8.27 (d, J = 2 Hz, 1H),
4.16 (t, J = 6.0 Hz, 2H), 4.07 (s, 3H), 3.82 (t, J = 6.0 Hz), 1.42 (s, 9H); 13C NMR
(CDCl3) d 168.2, 167.1, 151.1, 139.8, 130.1, 130.0, 128.5, 123.5, 53.5, 46.4, 43.2,
35.2, 31.6; 77Se NMR (CDCl3) d 909; FT-IR (KBr, cmꢂ1) 2956, 1674, 1637, 1445,
1346, 1293, 1263, 1202, 781, 592; ES-MS: m/z Calcd for C15H18ClNO3Se: 375.
Found: 376.01 [M+H]+(100%); Anal. Calcd for C15H18ClNO3Se: C, 48.08; H, 4.84;
N, 3.74. Found: C, 47.93; H, 3.92; N, 4.32.
19. Synthesis of 7: This compound was synthesized following the procedure
described for compound 6, using diselenide 5 (0.62 g, 1.0 mmol), Br2 (0.17 g,
1.1 mmol), CHCl3 (25 mL) and Et3N (0.28 mL, 2.0 mmol) and tris(2-
aminoethyl)amine in (0.1 mL, 0.67 mmol) CHCl3 (5.0 mL). Yield (0.22 g, 32%);
1H NMR (CDCl3) d 8.26 (d, J = 2.0 Hz, 3H), 8.21 (d, J = 1.6 Hz, 3H), 4.07 (t,
J = 6.4 Hz, 6H), 4.03 (s, 9H), 3.10 (t, J = 6.4 Hz, 6H), 1.39 (s, 27H); 13C NMR
(CDCl3) d 167.9, 167.0, 150.7, 140.1, 129.8, 129.6, 129.1, 123.6, 53.8, 53.3, 42.4,
35.1, 31.5; 77Se NMR (CDCl3) d 887; ES-MS: m/z calcd for C45H54N4O9Se3: 1032.
Found: 1033 [M+H]+(100%).
20. Synthesis of 8: To a stirred solution of diselenide 5 (0.33 g, 0.50 mmol) in CHCl3
(25 mL) was added bromine (30
l
L, 0.09 g, 0.58 mmol) at room temperature.
24. Synthesis of 16: To a methanolic solution of sodium methoxide, H2S was
bubbled for 15 min and to this compound 11 (0.30 g, 0.8 mmol) was added. The
reaction mixture was stirred at room temperature. Usual work-up of the
reaction mixture gave the desired compound. Yield (0.05 g, 18%); 1H
NMR(CDCl3) d 8.2 (d, J = 1.8 Hz, 1H), 7.94 (d, J = 2 Hz, 1H), 7.08 (t(br), 1H),
3.92 (q, J = 5.6 Hz, 2H), 3.82 (t, J = 6.0 Hz, 2H), 1.43 (s, 9H); 77Se NMR (DMSO-d6)
d 577; 13C NMR (CDCl3) d 196.4, 167.4, 151.0, 144.5, 134.6, 129.6, 127.8, 127.3,
43.7, 42.3, 35.2, 31.6; FT-IR (KBr, cmꢂ1) 3313, 2965, 1624, 1592, 1534, 1449,
1362, 1337, 1316, 1260, 1237, 1191, 1052, 837, 752, 573; ES-MS: m/z Calcd for
The reaction mixture was stirred at room temperature for 2 h. To the above
was added ethanolamine (0.15 mL, 0.15 g, 2.4 mmol). After the addition of
ethanolamine, the reaction mixture was stirred at room temperature for
30 min. The reaction mixture was poured into water and was washed both
with 1 N HCl, 5% aqueous NaHCO3 and water (twice). The organic layer dried
over sodium sulfate was evaporated to give
a pale yellow solid. It was
recrystallized from ethyl acetate and petroleum ether (1:2) mixture. Yield
(0.27 g, 73%): mp 160–162 °C; 1H NMR (CDCl3) d 8.30 (s, 1H), 8.25 (s, 1H), 4.04
(s, 3H), 4.03 (t, J = 4.4 Hz, 2H), 3.95 (t, J = 4.0 Hz, 2H), 1.42 (s, 9H); 13C NMR
(CDCl3) d 168.1, 167.8, 151.0, 140.1, 130.0, 129.8, 128.8, 123.5, 62.7, 53.5, 47.7,
35.1, 31.5; 77Se NMR (CDCl3) d 908; FT-IR (KBr, cmꢂ1) 3529, 3285, 2966, 2925,
2870, 1679, 1611, 1477, 1452, 1338, 1259, 1195, 1074, 998, 780, 590; ES-MS:
m/z Calcd for C15H19NO4Se: 357. Found: 358 [M+H]+(100%); Anal. Calcd for
C
15H19NO3SSe: 374.99. Found: 377.89 (100%).
25. Bachrach, S. M.; Demoin, D. W.; Luk, M.; Miller, J. V., Jr. J. Phys. Chem. A 2004,
108, 4040.
26. In our previous study we found that the presence of methyl ester function as a
donor group (Seꢀ ꢀ ꢀO secondary bonding interaction) in cyclic selenenate ester
or diselenides lowered their catalytic antioxidant activity.16 Similarly, the
compounds reported in this Letter do not show any significant activity in bio-
assay. However, all the ebselen analogs with amide as donor groups displayed
slightly better activity than ebselen.11 Therefore, we speculate that if the ester
groups are modified to the amide group, the antioxidant activity of such
compounds could be enhanced.
C15H19NO4Se: C, 50.57; H, 5.38; N, 3.93. Found: C, 49.78; H, 5.83; N, 4.33.
21. Synthesis of 9: This compound was synthesized using the procedure outlined
for compound 8. A stirred solution of diselenide 5 (0.66 g, 1.0 mmol) in 25 mL
of CHCl3 was treated with bromine (62 lL, 0.19 g, 1.2 mmol) at room
temperature. The reaction mixture was stirred for 2 h and to this was added
N,N0-dimethylethylenediamine (0.19 g, 0.24 mL, 2.2 mmol). After stirring for