G. Singh et al. / Tetrahedron 58 (2002) 2471±2480
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3.5.7. 2-Chloro-9-methyl-quinolino[2,3-b]chroman-12-
one (8g). The title compound (8g) was obtained by treating
5d (313 mg, 1 mmol) with sulfuric acid as light green solid
(277 mg);(Found: C, 69.23;H, 3.53;N, 4.90. C 17H10NO2Cl
requires C, 69.05;H, 3.41;N, 4.74%); lmax (CH3CN): 385,
372, 317, 250, 207 nm; nmax (KBr): 1655, 1600, 1508,
1470 cm21; dH (200 MHz, CDCl3): 2.61 (s, 3H, CH3),
7.57 (d, 1H, J8.8 Hz), 7.72 (bd, 2H, J8.8 Hz), 7.83 (s,
1H, C10±H), 7.99 (d, 1H, J8.6 Hz, C3±H), 8.27 (d, 1H,
J2.5 Hz, C5±H), 9.16 (s, 1H, C11±H); m/z (%) 297
(M112, 0.2), 296 (M111, 0.3), 295 (M1, 3), 169 (100),
112 (29), 111 (41), 94 (22), 89 (31), 84 (35), 83 (46), 69
(48).
J8.2, 9.2 Hz, C9±H, C8±H), 8.16 (d, 1H, J9.2 Hz,
C7±H), 8.40 (dd, 1H, J8.0, 1.5 Hz, C1±H), 8.80 (br
d, 1H, J8.2 Hz, C12±H), 10.00 (s, 1H, C13±H); dC
(100 MHz, CDCl3): 115.37 (C13a), 118.53 (C4), 121.37
(C14a), 123.14 (CH), 123.83 (C12a0), 124.52 (CH),
126.77 (CH), 126.98 (CH), 127.86 (CH), 128.47 (CH),
129.15 (CH), 130.07 and 131.16 (C8a and C12a), 133.60
(CH), 135.67 (CH), 135.88 (CH), 150.93 (C6a), 156.11
(C4a), 158.25 (C5a), 178.08 (C14); m/z (%) 298 (M111,
1), 297 (M1, 5), 169 (100), 112 (30), 111 (41), 97 (29), 94
(28), 85 (25), 84 (35), 83 (48).
3.5.12. 2-Chlorobenzo( f )quinolino[2,3-b]chroman-14-
one (8l). The title compound (8l) was obtained by treating
5e (348 mg, 1 mmol) with sulfuric acid as golden yellow
solid. (323 mg);(Found: C, 72.56;H, 3.24;N, 4.34.
C20H10NO2Cl requires C, 72.41;H, 3.04;N, 4.22%); lmax
(CH3CN): 386.5, 367, 348.5, 290, 247 nm; nmax (KBr):
1656, 1604, 1480, 1465, 1410, 1381 cm21; dH (200 MHz,
CDCl3): 7.64±7.82 (m, 4H, arom.-Hs), 7.82±7.96 (m, 2H,
arom.-Hs), 8.16 (d, 1H, J9.2 Hz, arom.-H, C7±H), 8.34 (d,
1H, J1.5 Hz, C1±H), 8.78 (d, 1H, J8.0 Hz, C12±H),
9.96 (s, 1H, C13±H); m/z (%) 333 (M112, 7), 332
(M111, 4), 331 (M1, 10), 169 (100), 112 (28), 111 (46),
94 (22), 89 (31), 84 (33), 83 (46).
3.5.8. 2-Chloro-9-methoxy-quinolino[2,3-b]chroman-12-
one (8h). The title compound (8h) was obtained by
treating 5c (329 mg, 1 mmol) with sulfuric acid as light
green solid. (295 mg);(Found: C, 65.69;H, 3.37;N, 4.43.
C17H10NO3Cl requires C, 65.50;H, 3.23;N, 4.49%); lmax
(CH3CN): 400.5, 315, 307, 255, 211 nm; nmax (KBr):
1658 (sharp), 1602, 1560, 1509, 1470 cm21; dH (200
MHz, CDCl3): 3.91 (s, 3H, OCH3), 7.16±7.22 (m, 1H,
arom.-Hs), 7.53±7.48 (m, 2H, arom.-Hs), 7.66±7.62 (m,
1H, arom.-Hs), 7.92 (d, 1H, J8.5 Hz, C3±H), 8.22 (bs,
1H, C1±H), 9.08 (s, 1H, C11±H); m/z (%) 311 (M1, (2)),
169 (98), 112 (31), 111 (45), 94 (22), 89 (29), 70 (69), 69
(48), 59 (100).
3.5.13. 6-Chloro-1H-[1]-benzopyrano[2,3-c]pyrazole-4-
one (9). 6-Chloro-2-N-methylanilino-3-formyl-chromone
(4b, 313 mg, 1 mmol) was dissolved in hot aqueous aceto-
nitrile (80:20, 60 mL) and the hydrazine hydrate (50 mg,
1 mmol) was added to the above solution, and the contents
stirred overnight at room temperature. A yellow solid
(110 mg), practically insoluble in any solvent, separated
out, which was ®ltered off. The ®ltrate was concentrated
under vacuum to ,1/5 of its original volume and kept at
room temperature, when the title compound (9) separated
out as a white crystalline solid in a day, and was re-crystal-
lized from acetone (99 mg, 45%);mp 241±242 8C;(Found:
C, 54.26;H, 2.39;N, 12.93. C 10H5N2O2Cl requires C, 54.44;
H, 2.28;N, 12.70%); lmax (MeOH): 322, 265, 223 nm; nmax
(KBr): 3274, 1649, 1636, 1586, 1465 cm21; dH (300 MHz,
DMSO-d6): 7.49 (d, 1H, J8.9 Hz, C8±H), 7.64 (dd, 1H,
J8.9, 2.73 Hz, C7±H), 8.20 (d, 1H, J2.7 Hz, C5±H),
8.24 (s, 1H, C3±H), 13.57 (b, 1H, N±H); dC(75 MHz,
DMSO-d6): 105.30 (C3), 119.35 (C8), 123.01 (C4a),
125.59 (C5), 127.95 (C10), 128.33 (C6), 133.70 (C7),
153.80 (C8a), 161 (C2), 173 (C4); m/z (%) 222 (M112,
18), 221 (M111, 9), 220 (M1, 45), 171 (10), 167 (29),
149 (72), 112 (15), 83 (77), 71 (58), 58 (100).
3.5.9. 2-Chloro-7-methoxy-quinolino[2,3-b]chroman-12-
one (8i). The title compound (8i) was obtained by treating
5f (329 mg, 1 mmol) with sulfuric acid as light green solid
(299 mg);(Found: C, 65.66;H, 3.37;N, 4.56. C 17H10NO3Cl
requires C, 65.50;H, 3.23;N, 4.49%);
lmax (CH3CN):
392.5, 347.5, 317.5, 272, 235 nm; nmax (KBr): 1661, 1605,
1558, 1519, 1498, 1477 cm21; dH (200 MHz, CDCl3): 4.07
(s, 3H, OCH3), 7.12±7.19 (m, 1H, arom.-H), 7.42±7.68 (m,
4H, arom.-Hs), 8.22 (d, 1H, 2.8 Hz, C1±H), 9.17 (s, 1H,
C11±H); m/z (%) 312 (M111, 19), 311 (M1, 48), 169
(100), 112 (31), 111 (47), 89 (29), 84 (32), 83 (47), 69 (44).
3.5.10.
2,9-Dichloro-quinolino[2,3-b]chroman-12-one
(8j). The title compound (8j) was obtained by treating 5g
(333 mg, 1 mmol) with sulfuric acid, as light green solid.
(286 mg);(Found: C, 60.93;H, 2.41;N, 4.28. C 16H7NO2Cl2
requires C, 60.79;H, 2.23;N, 4.43%);
lmax (CH3CN):
370.5, 313, 304, 252, 207.5 nm; nmax (KBr): 1645, 1604,
1588, 1551, 1451, 1404, 1297 cm21; dH (200 MHz,
CDCl3): 7.36±7.21 (m, 2H, arom.-Hs), 7.52±7.41 (m, 3H,
arom.-Hs), 8.25 (d, 1H, J2.6 Hz, C1±H), 9.11 (s, 1H,
C11±H); m/z (%) 316 (M111, 1), 315 (M1, 2), 169 (92),
112 (29), 11 (45), 94 (22), 89 (29), 84 (36), 58 (100).
3.5.14. 3-Chloro-12H-[1]-benzopyrano[2,3-e]-1,5-benzo-
diazepine (10). Chromone (4b, 313 mg, 1 mmol) was
dissolved in re¯uxing aqueous acetonitrile (80:20) and the
solution of o-phenylenediamine (108 mg, 1 mmol) in aceto-
nitrile (4 mL) was added to the above re¯uxing solution.
The contents were re¯uxed for 6 h and cooled. A yellow
crystalline solid which separated out was ®ltered and
washed with little cold acetonitrile and re-crystallized
from hexane±CHCl3 (3:1), to obtain the title compound
(10, 278 mg, 94%);mp 273±274 8C;(Found: C, 64.89;H,
2.95;N, 9.32. C 16H9N2O2Cl requires C, 64.77;H, 3.06;N,
9.44%); lmax (MeOH): 406, 340, 302, 247 nm; nmax (KBr):
3315, 2960, 1663, 1641, 1602, 1581, 1564, 1499 cm21; dH
3.5.11. Benzo( f )quinolino[2,3-b]chroman-14-one (8k).
The title compound (8k) was obtained by treating 5l
(314 mg, 1 mmol) with sulfuric acid, as golden yellow
solid. (279 mg);(Found: C, 80.93;H, 3.62;N, 4.94.
C20H11NO2 requires C, 80.80;H, 3.73;N, 4.71%); lmax
(CH3CN): 384, 364.5, 346, 286, 278, 247.5, 219.5 nm;
nmax (KBr): 1664, 1645, 1610, 1445, 1404, 1310 cm21; dH
(400 MHz, CDCl3): 7.46 (ddd, 1H, J8.0, 7.4, 1.1 Hz,
C2±H), 7.67 (dd, 1H, J8.4, 1.1 Hz, C4±H), 7.71 (ddd,
1H, J8.4, 7.4, 1.5 Hz, C3±H), 7.80±7.84 (m, 2H, C10±
H, C11±H), 7.98 and 7.96 (overlapping doublets, 2H,