The Journal of Organic Chemistry
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afforded 4l as a yellow powder (72.4 mg, 63%). Characterization data
was consistent with that reported in the literature:16 Rf = 0.79 (CH2Cl2,
100%); 1H NMR (300 MHz, CDCl3) δ 8.51 (d, J = 7.2 Hz, 1H), 7.97 (d,
J = 6.9 Hz, 1H), 7.58À7.49 (m, 2H), 7.39À7.27 (m, 2H), 7.11 (t, J = 7.8
Hz 1H), 7.04 (s, 1H); 6.76 (t, J = 6.9 Hz, 1H); 13C NMR (75 MHz,
CDCl3) δ 151.8, 141.5, 133.6, 133.1, 132.3, 131.2, 130.2, 129.3, 127.8,
124.2, 119.1, 112.9, 99.0; IR (neat) 3031, 1634, 1518, 1462, 1333, 1048,
724 cmÀ1; HRMS calcd for C13H10ClN2 [M + H]+ 229.0527, found
229.05273.
2-(2-Bromophenyl)pyrazolo[1,5-a]pyridine (4m). The title com-
pound was prepared according to general procedure 4 using 0.5 mmol
of 2s. Purification by column chromatography (CH2Cl2, 100%) afforded
4m as a yellow-brown powder (96.0 mg, 70%). Characterization data
was consistent with that reported in the literature:16 Rf = 0.39 (CH2Cl2/
hexanes, 9/1); mp 45À46 °C; 1H NMR (300 MHz, CDCl3,) δ 8.51 (d,
J = 6.9 Hz, 1H), 7.83 (d, J = 7.2 Hz, 1H), 7.73 (d, J = 8.1 Hz, 1H), 7.58 (d,
J = 8.4 Hz, 1H), 7.43 (t, J = 7.8 Hz, 1H), 7.27 (t, J = 8.1 Hz, 1H), 7.14 (t,
J = 8.1 Hz, 1H), 6.99 (s, 1H), 6.78 (t, J = 6.6 Hz, 1H); 13C NMR (75
MHz, CDCl3) δ 153.5, 141.5, 135.4, 134.5, 132.7, 130.5, 129.3, 128.3,
124.2, 123.3, 119.0, 112.8, 98.8. IR (neat) 3055, 1633, 1519, 1458, 1330,
1024, 755, 737, 726 cmÀ1; HRMS calcd for C13H10BrN2 [M + H]+
273.00219, found 273.00219.
2-(3-Bromophenyl)pyrazolo[1,5-a]pyridine (4n). The title compound
was prepared according to General Procedure 4 using 0.5 mmol of 2u.
Purification by column chromatography (hexanes/EtOAc, 1:1) afforded
4n as a yellow-brown powder (81.5 mg, 60%): Rf = 0.63 (CH2Cl2/
hexanes, 9/1); mp 126 °C; 1H NMR (300 MHz, CDCl3,) δ 8.46 (d, J =
7.0 Hz, 1H), 8.14 (s, 1H), 7.88 (d, J = 7.8 Hz, 1H), 7.52À7.48 (m, 2H),
7.31 (t, J = 7.9 Hz, 1H), 7.10 (t, J = 7.8 Hz, 1H), 6.76À6.72 (m, 2H); 13C
NMR (75 MHz, CDCl3) δ 152.8, 142.5, 136.2, 132.1, 131.1, 130.2,
129.3, 125.8, 124.5, 123.8, 118.9, 113.0, 94.8; IR (neat) 3045, 1633,
1519, 1465, 1330, 1068, 772, cmÀ1. HRMS calcd for C13H10BrN2 [M +
H]+ 273.00219, found 273.00234.
δ 8.51 (d, J = 7.2 Hz, 1H), 7.96À7.92 (m, 3H), 7.50À7.38 (m, 3H), 7.69
(s, 1H), 6.83 (d, J = 7.4 Hz, 1H); 13C NMR (75 MHz, CDCl3) δ 156.1,
140.8, 132.7, 130.2, 130.1, 129.8, 127.5, 125.3, 118.4, 112.5, 107.7, 97.7;
IR (neat) 3048, 2229, 1523, 1476, 1455, 1431, 1258, 753, 718 cmÀ1
HRMS calcd for C14H10N3 [M + H]+ 220.08692, found 220.08705.
;
3/6-Methyl-2-phenylpyrazolo[1,5-a]pyridine (5b). The title com-
pound was prepared according to general procedure 4 using 1.0 mmol
of 1c. Purification by column chromatography (CH2Cl2/hexanes, 9/1)
afforded 5b a beige powder (45 mg, 77%, inseparable mixture of prod-
ucts). Characterization data was consistent with that reported in the
literature:16 Rf = 0.43 (CH2Cl2, 100%); mp 121À129 °C; 1H NMR (300
MHz, CDCl3) δ 8.29 (s, 1H), 7.98 (d, J = 7.5 Hz, 2H), 7.52À7.34 (m,
4H), 6.94 (d, J = 8.4 Hz, 1H), 6.75 (s, 1H); 13C NMR (75 MHz, CDCl3)
δ 153.7, 143.7, 141.2, 134.4, 129.6, 129.0, 127.4, 123.2, 122.4, 118.0,
112.7, 94.1, 93.5, 18.8; IR (neat) 1507, 1438, 1318, 1027, 809, 761, 691 cmÀ1
;
HRMS calcd for C14H13N2 [M + H]+ 209.10732, found 209.10685.
3/6-Chloro-2-phenylpyrazolo[1,5-a]pyridine (5c). The title com-
pound was prepared according to general procedure 4 using 1.0 mmol
of 1d. Purification by column chromatography (CH2Cl2/hexanes, 9/1)
afforded 5c as a beige powder (45 mg, 77%): Rf = 0.43 (CH2Cl2, 100%);
mp 121À129 °C; 1H NMR (major, 300 MHz, CDCl3) δ 9.42 (m, 1H),
9.22À9.20 (m, 2H), 8.15 (m, 4H), 8.10À8.04 (m, 7H), 7.70À7.65 (m,
3H), 7.58À7.46 (m, 18H), 7.08À6.99 (m, 6H); 13C NMR (major, 75
MHz, CDCl3) δ 154.7, 141.6, 133.5, 129.7, 127.9, 127.4, 124.6, 123.4,
111.9, 94.9; IR (neat) 3069, 3030, 1630, 1533, 745 cmÀ1; HRMS calcd
for C13H10ClN2 [M + H]+ 229.05270, found 229.05282.
2-Phenylpyrazolo[1,5-a]isoquinoline (5d). The title compound was
prepared according to General Procedure 4 using 1.0 mmol of 1e.
Purification by chromatography (CH2Cl2/hexanes, 9/1) afforded 5d as
a beige powder (73.7 mg, 60%). Characterization data was consistent
with that reported in the literature:16 Rf = 0.84 (CH2Cl2, 100%); mp
117 °C; 1H NMR (300 MHz, CDCl3) δ 8.27 (d, J = 6.9 Hz, 1H), 8.12 (d,
J = 7.8 Hz, 1H), 8.03 (d, J = 6.3 Hz, 2H), 7.65 (d, J = 8.1 Hz, 1H),
7.62À7.47 (m, 4H), 7.44À7.37 (m, 1H), 7.29 (s, 1H), 6.98 (d, 1H); 13C
NMR (75 MHz, CDCl3) δ 153.9, 140.7, 134.0, 129.7, 129.2, 128.8,
128.5, 128.1, 127.2, 125.3, 124.6, 113.0, 95.4. IR (neat) 1537, 1460,
1360, 792, 756, 695 cmÀ1; HRMS calcd for C17H13N2 [M + H]+
245.10732, found 245.1067.
2-Phenylpyrazolo[1,5-a]quinoline (5e). The title compound was
prepared according to General Procedure 4 using 1.0 mmol of 1f.
Purification by column chromatography (CH2Cl2/hexanes, 9/1) af-
forded 5e a yellow powder (110.2 mg, 90%). Characterization data was
consistent with that reported in the literature:16 Rf = 0.81 (CH2Cl2,
100%); mp 92À95 °C; 1H NMR (300 MHz, CDCl3) δ 8.70 (d, J = 8.7
Hz, 1H), 8.07 (d, J = 8.1 Hz, 2H), 7.75 (m, 2H), 7.52À7.37 (m, 4H),
6.90 (s, 1H); 13C NMR (75 MHz, CDCl3) δ 153.7, 140.4, 135.8, 134.4,
130.2, 129.6, 129.2, 129.1, 128.2, 125.5, 124.0, 117.5, 116.4, 97.6; IR
(neat) 1732, 1603, 1454, 1392, 1812, 743, 679 cmÀ1; HRMS calcd for
C17H13N2 [M + H]+ 245.10732, found 245.10727.
(E)-Ethyl 2-(Pyrazolo[1,5-a]pyridin-2-yl)acrylate (4o). The title
compound was prepared according to general procedure 4 using 0.4
mmol of 2v. Purification by column chromatography (CH2Cl2/hexanes,
9/1) afforded 4o a light brown oil (42.1 mg, 49% yield). Characteriza-
tion data was consistent with that reported in the literature:16 Rf = 0.26
(CH2Cl2/hexanes, 95/5); 1H NMR (300 MHz, CDCl3) δ 8.41 (d, J =
7.1 Hz, 1H), 7.79 (d, J = 16.1 Hz, 1H), 7.50 (d, J = 8.9 Hz, 1H), 7.12 (d,
J = 7.0 Hz, 1H), 6.78 (t, J = 6.9 Hz, 1H), 6.67 (m, 2H), 4.28 (q, J = 7.1 Hz,
2H), 1.34 (t, J = 7.1 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ 167.6,
150.3, 142.1, 137.2, 129.3, 124.6, 122.1, 119.2, 113.7, 97.4, 61.4, 15.1; IR
(neat) 2980, 1711, 1650, 1634, 1299, 1269, 1173, 1034, 979 cmÀ1
;
HRMS calcd for C12H13N2O2 [M + H]+ 217.09715, found 217.09671.
2-(2-Phenylcyclopropyl)pyrazolo[1,5-a]pyridine (4p). The title
compound was prepared according to General Procedure 4 using
0.5 mmol of 2w. Purification by column chromatography (CH2Cl2/
hexanes, 9/1) afforded 4p as a light brown powder (73 mg, 62%).
Characterization data was consistent with that reported in the litera-
7-Methoxy-2-phenylpyrazolo[1,5-a]quinoline (5f). The title com-
pound was prepared according to general procedure 4 using 0.3244
mmol of 1g. Purification by chromatography (CH2Cl2/hexanes, 1:1)
afforded 5f as a yellow powder (30.3 mg, 69%): Rf = 0.65 (CH2Cl2/
1
ture:16 Rf = 0.26 (CH2Cl2/hexanes, 95/5); mp 53À55 °C; H NMR
(300 MHz, CDCl3) δ 8.371 (d, J = 7.5 Hz, 1H), 7.35 (d, J = 8.4 Hz, 1H),
7.34À7.29 (m, 2H), 7.22À7.17 (m, 3H), 7.04 (t, J = 7.8 Hz, 1H), 6.65
(t, J = 6.9 Hz, 1H), 6.28 (s, 1H), 2.49À2.36 (m, 2H), 1.69À1.62 (m,
1H), 1.55À1.48 (m, 1H); 13C NMR (75 MHz, CDCl3) δ 157.6, 143.0,
142.0, 129.2, 129.0, 126.7, 126.6, 124.1, 118.1, 111.7, 94.4, 28.4, 22.6,
19.3. IR (neat) 3027, 1724, 1632, 1520, 1493, 745, 695 cmÀ1; HRMS
calcd for C16H15N2 [M + H]+ 235.12297, found 235.12373.
1
hexanes, 1:1); mp 98À100 C; H NMR (300 MHz, CDCl3) δ 8.61
(d, J = 9.1 Hz, 1H), 8.06 (d, J = 7.7 Hz, 2H), 7.45 (m, 3H), 7.35À7.27
(m, 3H), 7.15 (m, 1H), 6.88 (s, 1H), 3.93 (s, 3H); 13C NMR (75 MHz,
CDCl3) δ 157.4, 153.2, 139.4. 134.4. 130.6, 129.5, 129.0, 127.1, 125.0,
119.3, 117.94, 117.93, 110.2, 97.2, 56.5; IR (neat) 3372, 2935, 1728,
1619, 1563, 1167, 760 cmÀ1; HRMS calcd for C18H15N2O [M + H]+
275.11789, found 275.11824.
2-Phenylpyrazolo[1,5-a]pyridine-5-carbonitrile (5a). The title com-
pound was prepared according to general procedure 4 using 1.0 mmol of
1b. Purification by column chromatography (CH2Cl2/hexanes, 95/5)
affored 5a as a yellow powder (67.4 mg, 62%). Characterization data
was consistent with that reported in the literature:16 Rf = 0.76
(CH2Cl2, 100%); mp 186À189 °C; 1H NMR (300 MHz, CDCl3)
2-Phenylpyrazolo[1,5-a]pyrazine (5g). The title compound was
prepared according to General Procedure 4 using 0.5 mmol of 1h. Puri-
fication by column chromatography (CH2Cl2/hexanes, 9/1) afforded
5g as a white powder (81.5 mg, 60%): Rf = 0.63 (CH2Cl2/hexanes, 1:1);
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dx.doi.org/10.1021/jo201303x |J. Org. Chem. 2011, 76, 8243–8261