Mendeleev Commun., 2002, 12(5), 200–201
Reactions of thiopyranoindazoles 2 were studied using tri-
This work was supported by the Russian Foundation for Basic
Research (grant no. 01-03-32261).
cyclic compound 2a as an example. Compound 2a was readily
and selectively oxidised with aqueous H2O2 in CF3COOH or
AcOH to sulfone 5a or sulfoxide 6a, respectively (Scheme 2).
The alkaline hydrolysis of compound 2a resulted in tricyclic
carboxylic acid 7a (Scheme 2).
References
Thus, starting from 1-aryl-3-formyl-4,6-dinitro-1H-indazoles
1, which in turn were prepared from TNT, we synthesised two
types of 14π-electron peri-annelated tricyclic heteroaromatic
systems: 1H-thiopyrano[4,3,2-cd]indazoles and 1,5-dihydro-
pyrazolo[3,4,5-de]cinnolines.
Note that 14π-electron peri-annelated heteroaromatic systems
containing two six-membered rings and one five-membered
ring are a rare type of heterocycles (e.g., see refs. 2, 3). As for
tricyclic systems prepared in this work, we failed to find pub-
lished procedures for the synthesis of such systems; only the
pharmacological properties of 1H-thiopyrano[4,3,2-cd]indazoles
with other substituents were reported previously.4
2 V. V. Mezheritskii and V. V. Tkachenko, in Adv. Heterocycl. Chem.,
1990, vol. 51, p. 1.
3 S. Tumkevicius, Liebigs Ann. Chem., 1995, 1703.
4 L. M. Werbel, E. F. Elslager and D. F. Worth, Adv. Pharmacol. Ther., Proc.
7th Int. Congr. Pharmacol., 1979, vol. 10, pp. 3–8 (Chem. Abstr., 1980,
92, 215).
The structure and composition of the prepared compounds
1
were supported by H NMR spectroscopy, electron-ionization
mass spectrometry (the formation of molecular ions was detected
in all cases), IR spectroscopy and elemental analysis.†
†
1H NMR spectra were measured on a Bruker AM-300 spectrometer
with TMS as a standard compound.
1
2a: 60% yield, mp 230–231 °C (CHCl3). H NMR (CDCl3) d: 4.0 (s,
3
3
3H, Me), 7.45 (t, 1H, Ph, JH–H 7.2 Hz), 7.6 (t, 2H, Ph, JH–H 7.2 Hz),
3
7.7 (s, 1H, Harom), 7.75 (d, 2H, Ph, JH–H 7.2 Hz), 7.95 (s, 1H, Harom),
8.15 (s, 1H, Harom).
2b: 77% yield, mp > 300 °C (CHCl3). 1H NMR (CDCl3) d: 3.95 (s, 3H,
Me), 7.55 (d, 2H, Harom, 3JH–H 8.8 Hz), 7.6 (d, 3H, Harom, 3JH–H 8.8 Hz),
7.95 (s, 1H, Harom), 8.1 (s, 1H, Harom).
3a: 74% yield, mp 260–261 °C. 1H NMR ([2H6]DMSO) d: 6.8 (t, 1H,
Ph), 7.0 (d, 2H, Ph), 7.2 (t, 2H, Ph), 7.6 (t, 1H, Ph), 7.7 (t, 2H, Ph), 7.85
(d, 2H, Ph), 8.2 (s, 1H, CH=N), 8.55 (s, 1H, Harom), 8.75 (s, 1H, Harom),
10.6 (s, 1H, NH).
3b: 61% yield, mp 267–269 °C. 1H NMR ([2H6]DMSO) d: 6.9 (m, 1H,
3
Ph), 7.1–7.3 (m, 4H, Ph), 7.7 (s, 1H, CH=N), 7.8 (d, 2H, Harom, JH–H
8.0 Hz), 8.05 (d, 2H, Harom, 3JH–H 8.0 Hz), 8.8 (s, 1H, Harom), 8.9 (s, 1H,
H
arom), 11.75 (s, 1H, NH).
4a: 47% yield, mp 257–259 °C. 1H NMR (CDCl3) d: 7.1 (s, 1H, Harom),
7.4–7.55 (m, 2H, Ph), 7.6–7.7 (m, 6H, Ph), 7.8 (d, 2H, Ph, 3JH–H 7.2 Hz),
7.9 (s, 1H, Harom), 8.1 (s, 1H, CH=N).
4b: 52% yield, mp 264–265 °C. 1H NMR ([2H6]DMSO) d: 6.95 (s,
1H, Harom), 7.5 (m, 1H, Ph), 7.6 (m, 6H, Ph), 8.9 (m, 3H, Ph, Harom), 8.2
(s, 1H, CH=N).
5a: 81% yield, mp 218–220 °C (CHCl3). 1H NMR ([2H6]DMSO) d:
4.0 (s, 3H, Me), 7.5–7.8 (m, 3H, Ph), 7.9 (d, 2H, Ph, 3JH–H 7.9 Hz), 8.55
(s, 1H, CH), 8.75 (s, 1H, Harom), 8.9 (s, 1H, Harom).
6a: 38% yield, mp 224–225 °C (CHCl3). 1H NMR ([2H6]DMSO) d:
4.0 (s, 3H, Me), 7.6–7.8 (m, 3H, Ph), 7.9 (d, 2H, Ph, 3JH–H 7.3 Hz), 8.05
(s, 1H, CH), 8.6 (s, 1H, Harom), 8.9 (s, 1H, Harom).
7a: 81% yield, mp 303–304 °C (CHCl3). 1H NMR ([2H6]DMSO) d:
7.45 (t, 1H, 3JH–H 6.7 Hz, Ph), 7.6 (t, 2H, Ph, 3JH–H 7.3 Hz, Ph), 7.8 (m,
3H, Ph, CH), 8.1 (s, 1H, Harom), 8.25 (s, 1H, Harom).
Received: 15th July 2002; Com. 02/1968
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