Arch. Pharm. Chem. Life Sci. 2009, 342, 394–404
Preparation of Potential Antituberculosis Agents
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3.9 Hz), 124.4 (q, J = 3.9 Hz), 124.3, (q, J = 272.9 Hz), 123.9, 121.7,
61.5, 33.5, 14.2.
Ethyl 4-(4-fluorobenzylsulfanyl)pyridine-2-carboxylate 8e
1
Yield: 61%; m.p.: 77–798C; IR (KBr) mmax (cm– 1) 1728 (C=O); H-
NMR (300 MHz, DMSO-d6) d (ppm): 8.48 (dd, J = 5.2 Hz, J = 1.1 Hz,
1H, H6), 7.86 (dd, J = 1.7 Hz, J = 1.1 Hz, 1H, H3), 7.56-7.47 (m, 2H,
H5, Ar-H), 7.36–7.32 (m, 1H, Ar-H), 7.20–7.13 (m, 2H, Ar-H), 4.44
(s, 2H, CH2), 4.31 (dq, J = 7.1 Hz, J = 1.7 Hz, 2H, CH2), 1.30 (dt, J =
7.1 Hz, J = 1.7 Hz, 3H, CH3); 13C-NMR (75 MHz, DMSO-d6) d (ppm):
164.7, 161,6 (d, J = 243.0 Hz), 150.0, 149.5, 147.7, 132.5 (d, J =
3.2 Hz), 131.1 (d, J = 8.3 Hz), 123.8, 121.6, 115.6 (d, J = 21.6 Hz),
61.5, 33.4, 14.3.
Ethyl 4-(4-trifluoromethylbenzylsulfanyl)pyridine-2-
carboxylate 8k
Yield: 68%; m.p. 84–868C; IR (KBr) mmax (cm– 1): 1728 (C=O), 1327
(CF3); 1H-NMR (300 MHz, DMSO-d6) d (ppm): 8.48 (dd, J = 5.2 Hz, J =
0.4 Hz, 1H, H6), 7.87 (dd, J = 1.2 Hz, J = 0.4 Hz, 1H, H3), 7.70–7.65
(m, 4H, Ar-H), 7.56 (dd, J = 5.2 Hz, J = 1.2 Hz, 1H, H5), 4.56 (s, 2H,
CH2), 4.31 (q, J = 7.1 Hz, 2H, CH2), 1.30 (t, J = 7.1 Hz, 3H, CH3);13C-
NMR (75 MHz, DMSO-d6) d (ppm): 164.6, 149.6, 149.5, 147.8,
141.5, 129.8, 128.2 (q, J = 31.8 Hz), 125.7 (q, J = 3.9 Hz), 124.3, (q, J
= 272.9 Hz), 123.8, 121.6, 61.5, 33.6, 14.2.
Ethyl 4-(3-bromobenzylsulfanyl)pyridine-2-carboxylate 8f
Yield: 80%; m.p.: 66–688C; IR (KBr) mmax (cm– 1): 1733 (C=O); 1H-
NMR (300 MHz, DMSO-d6) d (ppm): 8.47 (dd, J = 5.3 Hz, J = 0.5 Hz,
1H, H6), 7.86 (dd, J = 1.8 Hz, J = 0.5 Hz, 1H, H3), 7.67 (s, 1H, Ar-H),
7.54 (dd, J = 5.3 Hz, J = 1.8 Hz, 1H, H5), 7.46 (d, J = 7.8 Hz, 2H, Ar-H),
7.29 (t, J = 7.8 Hz, 1H, Ar-H), 4.45 (s, 2H, CH2), 4.31 (q, J = 7.1 Hz,
2H, CH2), 1.30 (t, J = 7.1 Hz, 3H, CH3); 13C-NMR (75 MHz, DMSO-d6)
d (ppm): 164.6, 149.7, 149.5, 147.8, 139.3, 131.8, 130.9, 130.5,
128.1, 123.8, 121.9, 121.6, 61.5, 33.5, 14.3.
Ethyl 4-(3-cyanobenzylsulfanyl)pyridine-2-carboxylate 8l
Yield: 66%; m.p.: 104-1068C; IR (KBr) mmax (cm– 1): 2230 (CN), 1735
(C=O); 1H-NMR (300 MHz, DMSO-d6) d (ppm): 8.48 (dd, J = 5.3 Hz, J
= 0.5 Hz, 1H, H6), 7.93 (s, 1H, Ar-H), 7.86 (dd, J = 1.9 Hz, J = 0.5 Hz,
1H, H3), 7.82–7.73 (m, 2H, Ar-H), 7.57–7.52 (m, 2H, H5, Ar-H), 4.51
(s, 2H, CH2), 4.31 (q, J = 7.1 Hz, 2H, CH2), 1.31 (t, J = 7.1 Hz, 3H,
CH3); 13C-NMR (75 MHz, DMSO-d6) d (ppm) 164.6, 149.5, 149.4,
147.8, 138.4, 133.9, 132.6, 131.5, 130.1, 123.8, 121.7, 118.7,
111.7, 61.5, 33.3, 14.3.
Ethyl 4-(4-bromobenzylsulfanyl)pyridine-2-carboxylate 8g
Yield: 83%; m.p.: 108–1108C; IR (KBr) mmax (cm– 1): 1730 (C=O); 1H-
NMR (300 MHz, DMSO-d6) d (ppm): 8.47 (dd, J = 5.3 Hz, J = 0.5 Hz,
1H, H6), 7.85 (dd, J = 1.9 Hz, J = 0.5 Hz, 1H, H3), 7.55–7.51 (m, 3H,
H5, Ar-H), 7.43–7.40 (m, 2H, Ar-H), 4.43 (s, 2H, CH2), 4.31 (q, J =
7.1 Hz, 2H, CH2), 1.30 (t, J = 7.1 Hz, 3H, CH3); 13C-NMR (75 MHz,
DMSO-d6) d (ppm): 164.6, 149.8, 149.5, 147.7, 135.9, 131.7, 131.2,
123.8, 121.6, 120.8, 61.5, 33.5, 14.3.
Ethyl 4-(3-methoxybenzylsulfanyl)pyridine-2-carboxylate
8m
Yield: 66%; m.p.: 73–758C; IR (KBr) mmax (cm– 1): 1714 (C=O), 1266
1
(OCH3), 1044 (OCH3); H-NMR (300 MHz, DMSO-d6) d (ppm) 8.47
Ethyl 4-(3-methylbenzylsulfanyl)pyridine-2-carboxylate
8h
(dd, J = 5.3 Hz, J = 0.5 Hz, 1H, H6), 7.87 (dd, J = 2.0 Hz, J = 0.5 Hz,
1H, H3), 7.54 (dd, J = 5.3 Hz, J = 2.0 Hz, 1H, H5), 7.24 (t, J = 8.1 Hz,
1H, Ar-H), 7.03–7.01 (m, 2H, Ar-H), 6.85–6.81 (m, 1H, Ar-H), 4.40
(s, 2H, CH2), 4.31 (q, J = 7.1 Hz, 2H, CH2), 3.72 (s, 3H, OCH3), 1.30 (t,
J = 7.1 Hz, 3H, CH3); 13C-NMR (75 MHz, DMSO-d6) d (ppm) 164.7,
159.5, 150.3, 149.4, 147.7, 137.8, 129.9, 123.7, 121.5, 121.2,
114.7, 113.1, 61.5, 55.2, 34.3, 14.3.
Yield: 63%; m.p.: 44–468C; IR (KBr) mmax (cm– 1): 1720 (C=O); 1H-
NMR (300 MHz, DMSO-d6) d (ppm): 8.47 (dd, J = 5.3 Hz, J = 0.6 Hz,
1H, H6), 7.87 (dd, J = 2.0 Hz, J = 0.6 Hz, 1H, H3), 7.53 (dd, J = 5.3 Hz,
J = 2.0 Hz, 1H, H5), 7.26–7.18 (m, 3H, Ar-H), 7.08–7.06 (m, 1H, Ar-
H), 4.38 (s, 2H, CH2), 4.31 (q, J = 7.1 Hz, 2H, CH2), 2.27 (s, 3H, CH3),
1.31 (t, J = 7.1 Hz, 3H, CH3); 13C-NMR (75 MHz, DMSO-d6) d (ppm):
164.7, 150.3, 149.4, 147.7, 138.0, 136.0, 129.7, 128.7, 128.3,
126.2, 123.7, 121.5, 61.5, 34.3, 21.1, 14.3.
Ethyl 4-(4-nitrobenzylsulfanyl)pyridine-2-carboxylate 8n
Yield: 72%; m.p.: 106–1078C; IR (KBr) mmax (cm– 1): 1733 (C=O),
1523 (NO2), 1349 (NO2);1H-NMR (300 MHz, DMSO-d6) d (ppm): 8.48
(dd, J = 5.3 Hz, J = 0.6 Hz, 1H, H6), 8.19 (d, J = 8.8 Hz, 2H, Ar-H), 7.87
(dd, J = 2.0 Hz, J = 0.6 Hz, 1H, H3), 7.73 (d, J = 8.8 Hz, 2H, Ar-H), 7.56
(ddd, J = 5.3 Hz, J = 2.0 Hz, J = 0.7 Hz, 1H, H5), 4.61 (s, 2H, CH2),
4.30 (dq, J = 7.1 Hz, J = 0.7 Hz, 2H, CH2), 1.30 (dt, J = 7.1 Hz, J =
0.7 Hz, 3H, CH3); 13C-NMR (75 MHz, DMSO-d6) d (ppm): 164.6,
149.6, 149.3, 147.8, 147.8, 147.0, 144.8, 130.3, 123.9, 121.8, 61.6,
33.5, 14.3.
Ethyl 4-(4-methylbenzylsulfanyl)pyridine-2-carboxylate 8i
Yield: 60%; m.p.: 75–778C; IR (KBr) mmax (cm– 1): 1722 (C=O); 1H-
NMR (300 MHz, DMSO-d6) d (ppm): 8.45 (dd, J = 5.3 Hz, J = 0.5 Hz,
1H, H6), 7.90 (dd, J = 2.0 Hz, J = 0.5 Hz, 1H, H3), 7.56 (dd, J = 5.3 Hz,
J = 2.0 Hz, 1H, H5), 7.33 (d, J = 7.9 Hz, 2H, Ar-H), 7.14 (d, J = 7.9 Hz,
2H, Ar-H), 4.39 (s, 2H, CH2), 4.31 (q, J = 7.1 Hzv, CH2), 2.25 (s, 3H,
CH3), 1.30 (t, J = 7.1 Hz, 3H, CH3); 13C-NMR (75 MHz, DMSO-d6) d
(ppm): 164.6, 150.4, 149.3, 147.8, 137.0, 132.9, 129.4, 129.0,
123.8, 121.6, 61.5, 34.0, 20.9, 14.3.
Ethyl 4-(3,5-dinitrobenzylsulfanyl)pyridine-2-carboxylate
Ethyl 4-(3-trifluoromethylbenzylsulfanyl)pyridine-2-
carboxylate 8j
8o
Yield: 72%; m.p.: 136–1388C; IR (KBr) mmax (cm– 1): 1726 (C=O),
1536 (NO2), 1339 (NO2);1H-NMR (300 MHz, DMSO-d6) d (ppm): 8.78
(d, J = 2.1 Hz, 2H, Ar-H), 8.70 (t, J = 2.1 Hz, 1H, Ar-H), 8.49 (dd, J =
5.3 Hz, J = 0.6 Hz, 1H, H6), 7.91 (dd, J = 2.0 Hz, J = 0.6 Hz, 1H, H3),
7.61 (ddd, J = 5.3 Hz, J = 2.0 Hz, J = 0.6 Hz, 1H, H5), 4.76 (s, 2H,
CH2), 4.31 (q, J = 7.1 Hz, 2H, CH2), 1.30 (t, J = 7.1 Hz, 3H, CH3); 13C-
NMR (75 MHz, DMSO-d6) d (ppm): 164.5, 149.7, 148.6, 148.3,
147.9, 141.8, 129.4, 124.0, 121.9, 117.9, 61.6, 32.6, 14.2.
Yield: 76%; m.p.: 45–478C; IR (KBr) mmax (cm– 1): 1716 (C=O), 1331
(CF3);1H-NMR (300 MHz, DMSO-d6) d (ppm): 8.48 (dd, J = 5.3 Hz, J =
0.5 Hz, 1H, H6), 7.88 (dd, J = 1.9 Hz, J = 0.5 Hz, 1H, H3), 7.83 (s, 1H,
Ar-H), 7.78–7.76 (m, 1H, Ar-H), 7.64–7.54 (m, 3H, H5, Ar-H), 4.56
(s, 2H, CH2), 4.31 (q, J = 7.1 Hz, 2H, CH2), 1.30 (t, J = 7.1 Hz, 3H,
CH3); 13C-NMR (75 MHz, DMSO-d6) d (ppm): 164.6, 149.6, 149.5,
147.8, 138.1, 133.2, 129.9, 129.4 (q, J = 31.8 Hz), 125.7 (q, J =
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