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HETEROCYCLES, Vol. 75, No. 4, 2008
3-Butylbenzo[b]thiophene-2-carbonitrile (2c): a yellow oil; Rf 0.64 (1:5 AcOEt–hexane); IR (neat)
3061, 2214 cm–1; 1H NMR δ 0.97 (3H, t, J 7.3), 1.45 (2H, sextet, J 7.3), 1.69–1.77 (2H, m), 3.08 (2H, t,
J 7.8), 7.48 (1H, ddd, J 7.8, 7.3, 1.4), 7.52 (1H, ddd, J 7.8, 7.3, 1.4), 7.84 (2H, dd, J 7.8, 1.4); MS m/z
215 (M+, 35), 172 (100). Anal. Calcd for C13H13NS: C, 72.52; H, 6.09; N, 6.51. Found: C, 72.26; H,
6.10; N, 6.30.
(3-Butylbenzo[b]thiophen-2-yl)(phenyl)methanone (2d): a yellow oil; Rf 0.51 (1:5 AcOEt–hexane);
1
IR (neat) 3059, 1643 cm–1; H NMR δ 0.90 (3H, t, J 7.3), 1.38 (2H, sextet, J 7.3), 1.63–1.69 (2H, m),
3.09 (2H, t, J 7.8), 7.44–7.50 (4H, m), 7.60 (1H, tt, J 7.3, 1.4), 7.85 (1H, dd, J 7.3, 1.4), 7.88–7.91 (3H,
m); MS m/z 294 (M+, 27), 251 (100). Anal. Calcd for C19H18OS: C, 77.51; H, 6.16. Found: C, 77.33; H,
6.21.
1,1-Dimethylethyl 3-(1,1-Dimethylethyl)benzo[b]thiophene-2-carboxylate (2e): white powder; mp
1
123–125 ˚C (hexane–Et2O); IR (KBr disk) 3063, 1722 cm–1; H NMR δ 1.06 (9H, s), 1.44 (9H, s),
7.08–7.11 (2H, m), 7.21 (1H, ddd, J 7.8, 7.3, 1.4), 7.26 (1H, dd, J 7.8, 1.4); MS m/z 290 (M+, 26), 234
(100). Anal. Calcd for C17H22O2S: C, 70.31; H, 7.64. Found: C, 70.30; H, 7.69.
3-(1,1-Dimethylethyl)benzo[b]thiophene-2-carbonitrile (2f): pale-yellow powder; mp 72–74 ˚C
(hexane–Et2O); IR (KBr disk) 3060, 2208 cm–1; 1H NMR δ 1.70 (9H, s), 7.43 (1H, ddd, J 8.2, 7.3, 1.4),
7.48 (1H, ddd, J 8.2, 7.3, 1.4), 7.81 (1H, d, J 8.2), 8.19 (1H, d, J 8.2); MS m/z 215 (M+, 29), 200 (100).
Anal. Calcd for C13H13NS: C, 72.52; H, 6.09; N, 6.51. Found: C, 72.39; H, 6.26; N, 6.68.
3-Phenylbenzo[b]thiophene-2-carbonitrile (2g): white powder; mp 79–81 ˚C (hexane–Et2O) (lit.,9
78–81 ˚C). The IR and 1H NMR data for this product were identical to those reported previously.9
1,1-Dimethylethyl 3-(4-Chlorophenyl)benzo[b]thiophene-2-carboxylate (2h): white powder; mp
148–150 ˚C (hexane–Et2O); IR (KBr disk) 3061, 1690 cm–1; 1H NMR δ 1.40 (9H, s), 7.32 (2H, d, J 8.2),
7.34 (1H, ddd, J 7.8, 7.3, 1.4), 7.45–7.48 (4H, m), 7.87 (1H, dd, J 7.8, 1.4); MS m/z 344 (M+, 23), 288
(100). Anal. Calcd for C19H17ClO2S: C, 66.17; H, 4.97. Found: C, 66.14; H, 4.99.
3-(4-Chlorophenyl)benzo[b]thiophene-2-carbonitrile (2i): white powder; mp 162–163 ˚C
(hexane–Et2O); IR (KBr disk) 3072, 2216 cm–1; 1H NMR δ 7.49 (1H, dd, J 8.2, 7.3), 7.54–7.60 (5H, m),
7.81 (1H, d, J 8.2), 7.91 (1H, d, J 8.2); MS m/z 269 (M+, 100). Anal. Calcd for C15H8ClNS: C, 66.79; H,
2.99; N, 5.19. Found: C, 66.64; H, 2.93; N, 5.05.
[3-(4-Chlorophenyl)benzo[b]thiophen-2-yl](phenyl)methanone (2j): pale-yellow powder; mp 89–91
1
˚C (hexane–Et2O); IR (KBr disk) 3061, 1645 cm–1; H NMR δ 7.21–7.24 (6H, m), 7.40 (1H, t, J 7.3),
7.43 (1H, dd, J 8.2, 7.3), 7.52 (1H, dd, J 8.2, 7.3), 7.63 (2H, dd, J 8.2, 0.9), 7.71 (1H, d, J 8.2), 7.95 (1H,
d, J 8.2); MS m/z 348 (M+, 100). Anal. Calcd for C21H13ClOS: C, 72.30; H, 3.76; S, 9.19. Found: C,
72.23; H, 3.88; S, 9.46.
1,1-Dimethylethyl 3-(4-Methoxyphenyl)benzo[b]thiophene-2-carboxylate (2k): white powder; mp
121–123 ˚C (hexane–Et2O); IR (KBr disk) 3061, 1713 cm–1; 1H NMR δ 1.40 (9H, s), 3.88 (3H, s), 7.01