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M. Layek et al. / Tetrahedron 65 (2009) 4814–4819
5, flow: 1.0 mL/min, UV 220 nm, retention time 18.9 min; HRMS
4.15. 4-Chloro-1-(phenylsulfonyl)-2-(p-tolylethynyl)-1H-
pyrrolo[2,3-b]pyridine (3i)
(ESI): calcd for C18H16N2O3SCl (MþH)þ 375.0570, found 375.0575.
4.11. 5-(4-Chloro-1-(phenylsulfonyl)-1H-pyrrolo[2,3-
b]pyridin-2-yl)pent-4-yn-2-ol (3e)
This compound was obtained as yellow solid; mp 205 ꢀC; Rf (20%
acetone/n-hexane) 0.35; 1H NMR (DMSO-d6, 400 MHz)
d 8.40 (d,
J¼5.4 Hz, 1H), 8.10 (dd, J¼8.4 and 1.2 Hz, 2H), 7.54–7.72 (m, 5H),
This compound was obtained as white solid, mp 111–112 ꢀC; Rf
7.45 (d, J¼4.9 Hz,1H), 7.32 (d, J¼8.0 Hz, 2H), 7.17 (s,1H), 2.41 (s, 3H);
(30% acetone/n-hexane) 0.35; 1H NMR (DMSO-d6, 400 MHz)
d
8.39 (d,
13C NMR (DMSO-d6, 100 MHz)
d 24.5, 73.1, 97.8, 110.1 (2C), 118.2
J¼5.4 Hz, 1H), 8.09 (dd, J¼8.3 and 1.2 Hz, 2H), 7.72–7.61 (m, 3H), 7.48
(2C), 121.8, 121.9, 127.6 (2C), 128.8 (2C), 128.9 (2C), 130.7 (2C), 135.1,
135.5, 137.2, 144.3, 145.9; IR (cmꢂ1, KBr) 3118, 2210, 1383, 1183;
Mass (ES) m/z: 407 (Mþ1, 100%); HPLC 98.3%, column: Luna C 18
(150ꢁ4.6 mm), mobile phase A: 0.05% TFA in water; mobile phase
B: 0.05% TFA in acetonitrile, gradient (T/%B)¼0/5, 25/85, 30/95, 31/
5, flow: 1.0 mL/min, UV 220 nm, retention time 27.98 min; HRMS
(ESI): calcd for C22H15N2O2SCl (MþH)þ 407.0621, found 407.0621.
(d, J¼5.3 Hz,1H), 7.08 (s,1H), 4.94 (d, J¼4.4 Hz,1H), 3.94 (m,1H), 2.65
(m, 2H), 1.27 (d, J¼6.1 Hz, 3H); 13C NMR (DMSO-d6, 100 MHz)
d 22.8,
29.8, 64.9, 71.8, 99.0, 110.3, 119.8 (2C), 122.1, 127.2 (2C), 129.6 (2C),
134.8,134.9, 137.8,146.3,147.5; IR (cmꢂ1, KBr) 3436, 2925, 2233,1360,
1178; Mass (ES) m/z 375.0 (Mþ1, 100%); HPLC 97.9%, column: Luna C
18 (150ꢁ4.6 mm), mobile phase A: 0.05% TFA in water; mobile phase
B: 0.05% TFA in acetonitrile, gradient (T/%B)¼0/5, 25/85, 30/95, 31/5,
flow: 1.0 mL/min, UV 220 nm, retention time 19.5 min; HRMS (ESI):
calcd for C18H16N2O3SCl (MþH)þ 375.0570, found 375.0575.
4.16. 3-((4-Chloro-1-(phenylsulfonyl)-1H-pyrrolo[2,3-
b]pyridin-2-yl)ethynyl)aniline (3j)
4.12. 1-((4-Chloro-1-(phenylsulfonyl)-1H-pyrrolo[2,3-
b]pyridin-2-yl)ethynyl)cyclohexanol (3f)
This compound was obtained as light green solid; mp 190 ꢀC; Rf
(40% acetone/n-hexane) 0.3; 1H NMR (DMSO-d6, 400 MHz)
d 8.42
(d, J¼5.4 Hz, 1H), 8.08 (dd, J¼7.3 and 1.2 Hz, 2H), 7.73–7.64 (m, 3H),
7.51 (d, J¼5.4 Hz, 1H), 7.26 (s, 1H), 7.12 (t, J¼8.0 Hz, 1H), 6.86 (s, 1H),
6.79 (d, J¼7.6 Hz,1H), 6.68 (d, J¼8.1 Hz,1H), 5.32 (br s, 2H); 13C NMR
This compound was obtained as low melting brown solid; Rf
(30% acetone/n-hexane) 0.3; 1H NMR (DMSO-d6, 400 MHz) 8.41 (d,
J¼5.4 Hz, 1H), 8.08 (dd, J¼8.3 and 1.2 Hz, 2H), 7.73–7.63 (m, 3H),
7.49 (d, J¼5.3 Hz, 1H), 7.10 (s, 1H), 5.65 (s, 1H), 1.41–2.08 (m, 10H);
(DMSO-d6, 100 MHz)
d 78.2, 99.3, 110.7, 115.9 (2C), 118.8, 119.9,
120.0, 121.6 (2C),127.1 (2C),129.4, 129.8 (2C),134.9 (2C),135.1,137.7,
146.6, 147.8; IR (cmꢂ1, KBr) 3447, 3358, 3030, 2205,1377,1190; Mass
(ES) m/z: 408 (Mþ1, 100%); HPLC 97.6%, column: Luna C 18
(150ꢁ4.6 mm), mobile phase A: 0.05% TFA in water; mobile phase
B: 0.05% TFA in acetonitrile, gradient (T/%B)¼0/5, 25/85, 30/95, 31/
5, flow: 1.0 mL/min, UV 220 nm, retention time 18.2 min; HRMS
(ESI): calcd for C21H15N3O2SCl (MþH)þ 408.0574, found 408.0586.
13C NMR (DMSO-d6,100 MHz)
d 22.5 (2C), 24.6, 24.8, 67.0, 67.4, 72.8,
104.5, 110.7, 119.9 (2C), 121.6, 127.1 (2C), 129.7 (2C), 134.9 (2C), 137.8,
146.5, 147.6; IR (cmꢂ1, CHCl3) 3427, 3019, 2400, 2222, 1215;
Mass (ES) m/z 415.0 (Mþ1, 100%); HPLC 98.6%, column: Luna C 18
(150ꢁ4.6 mm), mobile phase A: 0.05% TFA in water; mobile phase B:
0.05% TFA in acetonitrile, gradient (T/%B)¼0/5, 25/85, 30/95, 31/5,
flow: 1.0 mL/min, UV 220 nm, retention time 23.1 min; HRMS (ESI):
calcd for C21H20N2O3SCl (MþH)þ 415.0883, found 415.0864.
4.17. Preparation of 4-phenyl-2-(phenylethynyl)-1-
(phenylsulfonyl)-1H-pyrrolo[2,3-b]pyridine (4)
4.13. 6-(4-Chloro-1-(phenylsulfonyl)-1H-pyrrolo[2,3-
b]pyridin-2-yl)hex-5-ynenitrile (3g)
A mixture of 3a (0.254 mmol), aq Cs2CO3 (1.0 mmol), PCy3
(0.012 mmol) and (PPh3)2PdCl2 (0.012 mmol) in 1,4-dioxane
(2.0 mL) was stirred for 10 min under nitrogen. Then phenyl bo-
ronic acid (0.381 mmol) was added and the mixture was stirred at
100 ꢀC for 1.0 h. After completion of the reaction, the mixture was
cooled to room temperature and extracted with ethyl acetate
(3ꢁ20 mL). The organic layers were collected, combined, washed
with saturated aq NaCl (2ꢁ5 mL), dried over anhydrous Na2SO4 and
concentrated under vacuum. The crude compound was purified by
column chromatography on silica gel using 30% ethyl acetate/
hexane to afford the desired product as white solid; mp 142 ꢀC; Rf
This compound was obtained as low melting brown solid; Rf
(20% acetone/n-hexane) 0.3; 1H NMR (DMSO-d6, 400 MHz) 8.39 (d,
J¼5.1 Hz,1H), 8.05 (dd, J¼8.4 and 1.2 Hz, 2H), 7.62–7.75 (m, 3H), 7.49
(d, J¼5.3 Hz, 1H), 7.14 (s, 1H), 2.40 (t, J¼7.0 Hz, 2H), 1.92 (t, J¼7.0 Hz,
2H), 1.75 (m, 2H); 13C NMR (DMSO-d6, 100 MHz)
d 17.6, 23.6, 23.7,
76.6, 98.9,110.8,119.8,119.9,120.1,121.7,127.2 (2C),129.7 (2C),134.9
(2C), 137.7, 146.5, 147.6; IR (cmꢂ1, KBr) 2924, 2247, 1186, 1215; Mass
(ES) m/z: 384.0 (Mþ1, 100%); HPLC 98.7%, column: Luna C 18
(150ꢁ4.6 mm), mobile phase A: 0.05% TFA in water; mobile phase B:
0.05% TFA in acetonitrile, gradient (T/%B)¼0/5, 25/85, 30/95, 31/5,
flow: 1.0 mL/min, UV 220 nm, retention time 21.8 min; HRMS (ESI):
calcd for C19H15N3O2SCl (MþH)þ 384.0574, found 384.0573.
(40% acetone/n-hexane) 0.3; 1H NMR (DMSO-d6, 400 MHz)
d 8.4 (d,
J¼5.6 Hz, 1H), 8.09 (m, 3H), 7.62–7.77 (m, 5H), 7.49 (d, J¼5.2 Hz,
2H), 7.10 (s, 1H), 5.0 (t, J¼5.6 Hz, 1H), 3.68 (m, 2H), 2.73 (t, J¼6.8 Hz,
2H); 13C NMR (DMSO-d6, 100 MHz)
d 23.8, 59.3, 71.7, 98.3, 112.0,
4.14. 4-Chloro-2-(phenylethynyl)-1-(phenylsulfonyl)-1H-
pyrrolo[2,3-b]pyridine (3h)
118.3, 118.6, 121.4, 127.2 (2C), 128.3 (2C), 129.0 (2C),129.5 (2C), 134.6
(2C), 136.2, 138.1, 141.6, 145.9, 145.8; IR (cmꢂ1, KBr) 3432, 3019,
2238, 1210; Mass (ES) m/z 403.0 (Mþ1, 100%); HPLC 98.1%, column:
Luna C 18 (150ꢁ4.6 mm), mobile phase A: 0.05% TFA in water;
mobile phase B: 0.05% TFA in acetonitrile, gradient (T/%B)¼0/5, 25/
85, 30/95, 31/5, flow: 1.0 mL/min, UV 220 nm, retention time
22.1 min; HRMS (ESI): calcd for C23H19N2O3S (MþH)þ 403.1116,
found 403.1132.
This compound was obtained as white solid, mp 165 ꢀC; Rf (20%
acetone/n-hexane) 0.3; 1H NMR (DMSO-d6, 400 MHz) 8.43 (d,
J¼5.4 Hz,1H), 8.10 (dd, J¼7.3and 1.5 Hz, 2H), 7.73–7.69 (m, 5H), 7.50–
7.56 (m, 4H), 7.32 (s, 1H); 13C NMR (DMSO-d6, 100 MHz)
d 74.6, 98.0,
111.2 (2C), 119.9 (2C), 121.1, 121.2, 127.1 (2C), 128.9 (2C), 129.8 (2C),
131.3 (2C),134.9,135.2,137.7,146.8,147.8; IR (cmꢂ1, KBr) 3428, 2096,
2400, 1638, 1196; Mass (ES) m/z: 393 (Mþ1, 100%); HPLC 97.7%,
column: Luna C 18 (150ꢁ4.6 mm), mobile phase A: 0.05% TFA in
water; mobile phase B: 0.05% TFA in acetonitrile, gradient (T/%B)¼0/
5, 25/85, 30/95, 31/5, flow: 1.0 mL/min, UV 220 nm, retention time
26.7 min; HRMS (ESI): calcd for C21H14N2O2SCl (MþH)þ 393.0465,
found 393.0459.
Acknowledgements
The authors thank Dr. V. Dahanukar and Mr. A. Mukherjee for
their encouragement and the analytical group for spectral data. Mr.
M.L. thanks CPS-DRL, Hyderabad, India for allowing him to pursue
this work as a part of his Ph.D. program.