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Med Chem Res (2012) 21:1861–1868
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1221(C–O). Anal. calcd for C12H11N3O4 (261.24): C,
55.17; H, 4.24; N, 16.50. Found: C, 55.33; H, 3.78; N,
16.50%.
Dark orange solid. Yield of 35%, m.p. 209–210°C. H
NMR (DMSO-d6) d: 2.28 (s, 3H, CH3), 2.32 (s, 3H, CH3),
3.11(q, J = 5.7 and 5.5 Hz, 2H, CH2), 3.53 (q, J = 5.7 and
6.0 Hz, 2H, CH2), 4.59 (t, J = 5.5 and 5.4 Hz, OH, disap.
in D2O), 6.61 (t, J = 5.4 Hz, 1H, NH, disap. in D2O), 7.18
(s, 1H, H-8), 7.71 (s, 1H, H-5), 8.15 (s, 1H, CH), 8.57 (bs,
1H, NH2, disap. in D2O), 9.14 (bs, 1H, NH2, disap. in
D2O). IR (cm-1, KBr): 3267 (NH), 3201 (OH), 3123
(NH2), 1643 (C=O), 1607 (CH=N). Anal. calcd for
C14H17N3O3 (275.29): C, 61.08; H, 6.22; N, 15.26. Found:
C, 60.95; H, 6.04; N, 15.10%.
4-{N-[1-(2-Amino-4-oxo-chromen-3-yl)meth-(E)-
ylidene]hydrazino}benzoic acid (9d)
Recrystallisation from ethanol; light yellow solid. Yield:
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75%, m.p. 342–343°C. H NMR (DMSO-d6) d: 6.90 (d,
J = 8.7 Hz, 2H, H-2, H-3, phenyl), 7.39–7.46 (m, 2H, H-6,
H-8, chromone ring), 7.67–7.72 (m, 1H, H-7, chromone
ring), 7.79 (d, J = 8.7 Hz, 2H, H-5, H-6, phenyl),
8.00–8.03 (dd, J = 1.7 and 7.7 Hz, 1H, H-5, chromone
ring), 8.53 (s, 1H, CH), 8.89–9.04 (bd, 2H, NH2, disap. in
D2O), 10.62 (s, 1H, NH, disap. in D2O), 12.22 (bs, 1H,
COOH, disap. in D2O). IR (cm-1, KBr): 3254 (OH), 3140
(NH2), 1665 (C=O), 1598 (CH=N), 1274 (C–O). Anal.
calcd. for C17H13N3O4 (323.31): C, 63.16; H, 4.05; N,
13.00. Found: C, 63.03; H, 4.18; N, 12.66%.
2-Amino-6-chloro-3-[(2-hydroxyethyl)-
hydrazonomethyl]chromen-4-one (11e)
An equimolar mixture of 2-amino-6-chloro-3-for-
mylchromone (4) (0.45 mmol) and 2-hydroxyethylhydra-
zine (5e) in 25 ml of toluene was refluxed at 181°C for
36 h. The mixture was cooled at -15°C, and the obtained
solid was filtered off, washed in cold toluene, and crys-
tallized from chloroform.
2-Amino-3-[(2-hydroxyethyl)hydrazonomethyl]-
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Yield 45%, m.p. 210–211°C. H NMR (DMSO-d6) d:
chromen-4-one (9e)
3.12 (q, J = 5.5 and 5.3 Hz, 2H, CH2), 3.54 (q, J = 5.5
and 5.7 Hz, 2H, CH2), 4.60 (t, J = 5.3 Hz, 1H, OH, disap.
in D2O), 6.75 (bs, 1H, NH, disap. in D2O), 7.46 (d,
J = 8.9 Hz, 1H, H-8), 7.67 (dd, J = 2.6 Hz, 1H, H-7),
7.90 (d, J = 2.6 Hz, 1H, H-5), 8.12 (s, 1H, CH), 8.83 (bs,
1H, NH2, disap. in D2O), 9.30 (bs, 1H, NH2, disap. in
D2O). IR (cm-1, KBr): 3248(OH), 3071 (NH), 1647
(C=O), 1611 (CH=N), 1253 (C–O). Anal. calcd. for
C12H12N3O3Cl (281.70): C, 51.17; H, 4.29; N, 14.92.
Found: C, 51.32; H, 4.11; N, 14.61%.
2-Amino-3-formylchromone (2) (1.06 mmol) was added at
room temperature to a solution of 3.51 mmol 2-hydroxy-
ethylhydrazine (5e) in 30 ml of anhydrous EtOH and was
refluxed for 2 h. The solution was evaporated, and the
residue was treated with 20 ml of H2O. The solid product
was filtered off, washed in H2O, dried, and crystallized
from chloroform.
Light orange solid. Yield 75%, m.p. 166–168°C. 1H
NMR (DMSO-d6) d: 3.11 (q, J = 6.0 and 5.5 Hz, 2H,
CH2), 3.53 (q, J = 5.5 and 6.0 Hz, 2H, CH2), 4.60 (t,
J = 5.5 Hz, 1H, OH, disap. in D2O), 6.68 (t, J = 5.4 Hz,
1H, NH, disap. in D2O), 7.35–7.41 (m, 2H, H-6, H-8),
7.61–7.67 (m, 1H, H-7), 7.98 (dd, J = 1.4 and 7.7 Hz, 1H,
H-5), 8.15 (s, 1H, CH), 8.69 (bs, 1H, NH2, disap. in D2O),
9.22 (bs, 1H, NH2, disap. in D2O). IR (cm-1, KBr): 3271
(OH), 3115 (NH2), 1642 (C=O), 1605 (CH=N), 1266 (C–
O). Anal. calcd. for C12H13N3O3 (247.26): C, 58.29; H,
5.30; N, 16.99. Found: C, 58.30; H, 5.15; N, 16.75%.
2-Amino-3-(benzylhydrylidenehydrazonomethyl)-
chromen-4-one (12)
An equimolar mixture of 2-amino-3-formylchromone (2)
(1 mmol) and hydrazine 5f was refluxed in 30 ml of
anhydrous ethanol for 18 h. The solid was filtered off
and washed in cold acetone to give TLC pure com-
pounds. Recrystallisation from acetone; small pale yel-
low solid.
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2-Amino-6,7-dimethylo-3-[(2-hydroxyethyl)-
Yield 55%, m.p. 264–265°C. H NMR (DMSO-d6) d:
hydrazonomethyl]chromen-4-one (10e)
7.28–7.31 (m, 2H, phenyl), 7.36–7.54 (m, 6H, phenyl, 2H,
chromone), 7.64–7.71 (m, 2H, phenyl and 1H, chromone
ring), 7.99–8.02 (dd, J = 1.4 and 7.7 Hz, 1H, H-5, chro-
mone ring), 9.07 (s, 1H, CH=N), 9.09 (bs, 1H, NH2, disap.
2-Amino-6,7-dimethylchromone (3) (0.46 mmol) was
added at room temperature to a solution of 0.46 mmol
2-hydroxyethylhydrazine (5e) in anhydrous toluene, and
the reaction mixture was heated in an oil bath at 117°C for
24 h. Then toluene was removed in vacuum, and the resi-
due was crystallized from acetone.
in D2O), 9.13 (bs, 1H, NH2, disap. in D2O). IR (cm-1
,
KBr): 3415 (NH2), 1656 (C=O), 1611 (C=N), 1242 (C–O).
Anal. calcd. for C23H17N3O2 (367.41): C, 75.19; H, 4.66;
N, 11.44. Found: C, 75.20; H, 4.22; N, 11.59%.
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