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(2JC4–F = 19.5 Hz, pyridine C-4), 128.5 (Ph-1), 128.9 (Ph-2,6), 129.0
(3JC5–F = 6.2 Hz, pyridine C-5), 140.8 (1J = 190.1 Hz, C-3), 141.8
(2JC2–F = 7.4 Hz, pyridine C-2), 143.7 (4JC6–F = 5.2 Hz, pyridine C-
6), 154.5 (C-5), 158.2 (1JC3–F = 267.8 Hz, pyridine C-3), 158.7 (Ph-
4), 190.8 (3JCO–F = 4.4 Hz, CO).
13C NMR (75 MHz, CDCl3): d = 50.0 (1J = 140.8 Hz, JCH2–H2,6
=
4.6 Hz, CH2), 55.3 (1J = 143.9 Hz, OMe), 103.5 (2JC4–H3 = 10.7 Hz,
C-4), 114.2 (Ph-3,5), 122.2 (pyridine C-5), 127.0 (2JC1–CH2 = 4.6 Hz,
3JC1–H3,5 = 7.6 Hz, Ph-1), 128.0 (pyridine C-3), 129.7 (Ph-2,6),
139.2 (1J = 190.7 Hz, C-3), 143.5 (3JC4–H2 = 4.7 Hz, JC4–H6 = 6.7
3
Hz, pyridine C-4), 148.0 (1J = 183.3 Hz, 2JC6–H5 = 2.3 Hz, 3JC6–H2
=
MS: m/z (%) = 327 (16) [M+], 121 (100).
11.3 Hz, pyridine C-6), 150.8 (1J = 187.9 Hz, 3JC2–H6 = 11.5 Hz, py-
ridine C-2), 157.9 (3JC5–CH2 = 2.6 Hz, 3JC5–H3 = 4.6 Hz, C-5), 159.6
(Ph-4), 187.3 (CO).
Anal. Calcd for C17H14FN3O3: C, 62.38; H, 4.31; N, 12.84. Found:
C, 62.27; H, 4.37; N, 12.65.
15N NMR (50 MHz, CDCl3): d = –187.4 (N-1), –95.9 (N-2); pyri-
(3-Chloropyridin-4-yl)-(5-hydroxy-3-methyl-1-phenyl-1H-
pyrazol-4-yl)methanone (13a)
Yield: 40%; mp 168–172 °C (aq EtOH).
dine N-1 was not found.
MS: m/z (%) = 345 (3) [M + 2]+, 343 (8) [M+], 121 (100).
IR (KBr): 1660 (C=O) cm–1.
HRMS (EI): m/z [M]+ calcd for C17H14N3O335Cl: 343.0724; found:
343.0731.
1H NMR (500 MHz, DMSO-d6): d = 2.36 (s, 3 H, Me), 5.03 (br s,
1 H, OH), 7.26 (m, 1 H, Ph-4), 7.41 (d, 3JH5–H6 = 5.0 Hz, 1 H, pyri-
dine H-5), 7.43 (m, 2 H, Ph-3,5), 7.61 (m, 2 H, Ph-2,6), 8.59 (d,
3JH6–H5 = 5.0 Hz, 1 H, pyridine H-6), 8.70 (s, 1 H, pyridine H-2).
Compounds 7f, 8f, 9f, 10f, and 11f; General Procedure
Under anhyd conditions, a solution of the PMB-substituted conge-
ner of type c and TFA (3–5 mL per mmol) was stirred overnight at
70 °C. After removal of excess TFA under reduced pressure, the
residue was dried over solid KOH for 1 h. Then ice-cold Et2O–ace-
tone (2:1, 3–5 mL per mmol) was added and the resulting suspen-
sion was filtered and the solid was washed with cold Et2O to give
the unsubstituted parent compounds of type f.
13C NMR (125 MHz, DMSO-d6): d = 14.1 (Me), 103.4 (C-4), 120.8
(Ph-2,6), 122.3 (pyridine C-5), 126.0 (Ph-4), 127.1 (pyridine C-3),
129.1 (Ph-3,5), 136.3 (Ph-1), 147.8 (pyridine C-6), 148.2 (pyridine
C-4), 148.5 (pyridine C-2), 150.6 (C-3), 159.4 (C-5), 184.6 (CO).
15N NMR (50 MHz, DMSO-d6): d = –199.8 (N-1), –66.5 (pyridine
N-1); N-2 was not found.
NMR data are presented in Tables 2–5.
MS: m/z (%) = 315 (17) [M + 2]+, 313 (50) [M+], 278 (100), 201
(14).
Pyrazolo[4¢,3¢:5,6]pyrano[3,2-b]pyridin-4(1H)-one (7f)
Yield: 89%; beige powder; mp 290–295 °C.
IR (KBr): 3434, 3098, 2902, 1679, 1659 (C=O) cm–1.
MS: m/z (%) = 187 (100) [M+].
HRMS (EI): m/z [M]+ calcd for C9H5N3O2: 187.0382; found:
187.0378.
Anal. Calcd for C16H12ClN3O2·H2O: C, 57.93; H, 4.25; N, 12.67.
Found: C, 58.13; H, 4.25; N, 12.67.
(3-Chloropyridin-4-yl)(5-hydroxy-1-phenyl-1H-pyrazol-4-
yl)methanone (13b)
Yield: 72%; mp 162–163 °C (aq EtOH).
IR (KBr): 1645 (C=O) cm–1.
Pyrazolo[4¢,3¢:5,6]pyrano[3,2-c]pyridin-4(1H)-one (8f)
1H NMR (300 MHz, DMSO-d6): d = 7.33 (m, 1 H, Ph-4), 7.55 (d,
3JH5–H6 = 4.9 Hz, 1 H, pyridine H-5), 7.48 (m, 2 H, Ph-3,5), 7.50
(br s, 1 H, OH), 7.68 (s, 1 H, H-3), 7.70 (m, 2 H, Ph-2,6), 8.65 (d,
3JH6–H5 = 4.9 Hz, 1 H, pyridine H-6), 8.77 (s, 1 H, pyridine H-2).
Yield: 62%; off-white powder; mp 335 °C (EtOH–DMF).
IR (KBr): 3111, 2812, 2652, 1683, 1674 (C=O) cm–1.
MS: m/z (%) = 187 (100) [M+], 135 (25), 110 (25).
HRMS (EI): m/z [M]+ calcd for C9H5N3O2: 187.0382; found:
187.0378.
13C NMR (75 MHz, DMSO-d6): d = 105.0 (2JC4–H3 = 9.4 Hz, C-4),
121.9 (Ph-2,6), 122.5 (1J = 168.4 Hz, 2JC5–H6 = 9.6 Hz, 4JC5–H2 = 1.3
Hz, pyridine C-5), 126.7 (Ph-4), 127.0 (2JC3–H2 = 4.6 Hz, JC3–H5
=
3
Pyrazolo[4¢,3¢:5,6]pyrano[2,3-c]pyridin-4(1H)-one (9f)
Yield: 64%; beige powder; mp 323–327 °C (EtOH–DMF).
IR (KBr): 3093, 2788, 2667, 1672 (C=O) cm–1.
MS: m/z (%) = 187 (100) [M+].
6.6 Hz, 4JC3–H6 = 2.1 Hz, pyridine C-3), 129.0 (Ph-3,5), 137.3 (Ph-
1), 141.4 (1J = 189.5 Hz, C-3), 146.4 (2JC4–H5 = 0.6 Hz, 3JC4–H2 = 4.4
Hz, 3JC4–H6 = 6.7 Hz, pyridine C-4), 148.0 (1J = 183.5 Hz, 2JC6–H5
=
3
2.5 Hz, JC6–H2 = 11.0 Hz, pyridine C-6), 149.2 (1J = 187.8 Hz,
3JC2–H6 = 11.5 Hz, pyridine C-2), 156.3 (3JC5–H3 = 4.9 Hz, C-5),
183.6 (3JCO–H5 = 4.0 Hz, CO).
Anal. Calcd for C9H5N3O2: C, 57.76; H, 2.69; N, 22.45. Found: C,
57.88; H, 2.70; N, 22.34.
15N NMR (50 MHz, DMSO-d6): d = –182.0 (N-1), –63.0 (pyridine
N-1); N-2 was not found.
MS: m/z (%) = 301 (14) [M + 2]+, 299 (38) [M+], 264 (100), 140
Pyrazolo[4¢,3¢:5,6]pyrano[2,3-b]pyridin-4(1H)-one (10f)
Yield: 10%; grayish powder; mp 308–315 °C (EtOH–DMF).
(12).
IR (KBr): 3424, 3157, 2926, 1681, 1650 (C=O) cm–1.
Anal. Calcd for C15H10ClN3O2·0.15 H2O: C, 59.57; H, 3.43; N,
13.89. Found: C, 59.59; H, 3.37; N, 13.83.
MS: m/z (%) = 187 (100) [M+].
HRMS (EI): m/z [M]+ calcd for C9H5N3O2: 187.0382; found:
187.0385.
(3-Chloropyridin-4-yl)-[5-hydroxy-1-(4-methoxybenzyl)-1H-
pyrazol-4-yl]methanone (13c)
Pyrazolo[4¢,3¢:5,6]pyrano[2,3-b]quinolin-4(1H)-one (11f)
Yield: 83%; yellowish oil.
IR (KBr): 1652 (C=O) cm–1.
Yield: 11%; off-white powder; mp 315–321 °C (EtOH–DMF).
IR (KBr): 3460, 3102, 2915, 1682, 1675 (C=O) cm–1.
MS: m/z (%) = 237 (100) [M+], 153 (13).
1H NMR (300 MHz, CDCl3): d = 3.79 (s, 3 H, OMe), 5.12 (s, 2 H,
CH2), 6.88 (m, 2 H, Ph-3,5), 7.31 (m, 2 H, Ph-2,6), 7.33 (d, 3JH5–H6
=
5.0 Hz, 1 H, pyridine H-5), 7.35 (s, 1 H, H-3), 7.83 (br s, 1 H, OH),
8.63 (br d, 3JH6–H5 = 5.0 Hz, 1 H, pyridine H-6), 8.74 (br s, 1 H, py-
ridine H-2).
Anal. Calcd for C13H7N3O2·0.18 H2O: C, 64.93; H, 3.09; N, 17.48.
Found: C, 65.32; H, 3.24; N, 17.09.
Synthesis 2006, No. 24, 4219–4229 © Thieme Stuttgart · New York