2-AMINOTHIOPHENE SYNTHESIS
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Table 3. Spectral data of synthesized products
Compound
Spectral data
Ethyl 2-amino-4,5-dimethylthiophene-3-
carboxylate (Table 1, entry 1)
1H NMR (CDCl3) d 1.29 (t, 3H, J ¼ 7.2 Hz), 2.20 (s,
3H), 2.36 (s, 3H), 4.30 (q, 2H, J ¼ 7.2 Hz), 6.99 (s,
2H); 13C NMR (CDCl3) d 9.8, 10.4, 14.1, 60.9, 112.9,
132.4, 134.9, 148.8, 165.7; IR (KBr) 1647, 3299,
3405 cmꢁ1. Anal. calcd. for C9H13NO2S: C, 54.25; H,
6.58; N, 7.03; S, 16.09. Found: C, 54.28; H, 6.60; N,
7.07; S, 16.07.
Ethyl 2-amino-5-methyl-4-phenylthiophene-3-
carboxylate (Table 1, entry 2)
1H NMR (CDCl3) d 1.31 (t, 3H, J ¼ 7.2 Hz), 1.99 (s,
3H), 4.33 (q, 2H, J ¼ 7.2 Hz), 6.83 (s, 2H), 7.41–7.52
(m, 5H); 13C NMR (CDCl3) d 12.3, 14.1, 60.2, 108.3,
127.5, 128.7, 129.2, 134.5, 136.1, 136.4, 159.9, 161.4;
IR (KBr) 1677, 3334, 3441 cmꢁ1. Anal. calcd. for
C14H15NO2S: C, 64.34; H, 5.79; N, 5.36; S, 12.27.
Found: C, 64.38; H, 5.81; N, 5.39; S, 12.29.
Ethyl 2-amino-4-phenylthiophene-3-carboxylate 1H NMR (CDCl3) d 1.28 (t, 3H, J ¼ 7.2 Hz), 4.30 (q,
(Table 1, entry 3)
2H, J ¼ 7.2 Hz), 6.39 (s, 1H), 6.91 (s, 2H), 7.40–7.53
(m, 5H); 13C NMR (CDCl3) d 14.4, 60.5, 105.1,
108.5, 127.7, 128.9, 129.6, 136.2, 143.6, 160.9, 164.8;
IR (KBr) 1670, 3332, 3440 cmꢁ1. Anal. calcd. for
C
13H13N O2S: C, 63.13; H, 5.30; N, 5.66; S, 12.97.
Found: C, 63.10; H, 5.28; N, 5.63; S, 12.92.
1H NMR (CDCl3) d 1.33 (t, 3H, J ¼ 7.2 Hz), 2.50 (s,
3H), 2.82 (s, 3H), 4.35 (q, 2H, J ¼ 7.2 Hz), 7.02 (s,
2H); 13C NMR (CDCl3) d 9.6, 14.5, 27.2, 60.6, 114.5,
142.8, 149.1, 161.4, 170.4, 191.1; IR (KBr) 1678,
3320, 3420 cmꢁ1. Anal. Calcd for C10H13NO3S: C,
52.85; H, 5.77; N, 6.16; S, 14.11. Found: C, 52.81; H,
5.73; N, 6.11; S, 14.09.
Ethyl 5-acetyl-2-amino-4-methylthiophene-3-
carboxylate (Table 1, entry 4)
Ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]-
thiophene-3-carboxylate (Table 1, entry 5)
1H NMR (CDCl3) d 1.33 (t, 3H, J ¼ 7.2 Hz), 1.73–1.75
(m, 4H), 2.46–2.48 (m, 2H), 2.69–2.71 (m, 2H), 4.25
(q, 2H, J ¼ 7.2 Hz), 6.01 (s, 2H); 13C NMR (CDCl3) d
14.5, 22.9, 23.3, 24.5, 27.0, 59.4, 105.5, 117.5, 132.4,
161.9, 166.6; IR (KBr) 1647, 3299, 3405 cmꢁ1. Anal.
calcd. for C11H15NO2S: C, 58.64; H, 6.71; N, 6.22; S,
14.23. Found: C, 58.68; H, 6.77; N, 6.28; S, 14.27.
1H NMR (CDCl3) d 2.20 (s, 3H), 2.35 (s, 3H), 6.87 (s,
2H); 13C NMR (CDCl3) d 9.5, 12.2, 83.3, 116.2,
2-Amino-4,5-dimethylthiophene-3-carbonitrile
(Table 1, entry 6)
117.1, 128.8, 149.7; IR (KBr) 2215, 3295, 3408 cmꢁ1
Anal. calcd. for C7H8N2S: C, 55.23; H, 5.30; N,
.
18.40; S, 21.07. Found: C, 55.28; H, 5.36; N, 18.46; S,
21.09.
2-Amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3- 1H NMR (CDCl3) d 1.69 (m, 4H), 2.33–2.39 (m, 4H),
carbonitrile (Table 1, entry 7)
6.92 (s, 2H); 13C NMR (CDCl3) d 22.1, 23.4, 24.1,
24.5, 88.4, 115.5, 120.7, 132.4, 161.1; IR (KBr) 2196,
3328, 3445 cmꢁ1. Anal. calcd. for C9H10N2S: C,
60.64; H, 5.65; N, 15.72; S, 17.99. Found: C, 60.69;
H, 5.67; N, 15.75; S, 18.02.
2-Amino-4-phenylthiophene-3-carbonitrile
(Table 1, entry 8)
1H NMR (CDCl3) d 6.96 (s, 2H), 7.14 (s, 1H),
7.43–7.54 (m, 5H); 13C NMR (CDCl3) d 79.8, 115.4,
127.7, 129.4, 129.9, 136.4, 139.1, 154.2; IR (KBr)
(Continued )