H.S.A. ElZahabi, M.S. Nafie, D. Osman et al.
European Journal of Medicinal Chemistry 222 (2021) 113609
4.1.9. 6,8-Dibromo-2-(2-hydrazinylvinyl)quinazolin-4(3H)-one
(15)
(cmꢂ1): 3414, 3132 (NH), 3066 (CH arom.), 2966-2920 (CH aliph.),
1676 (C¼O),1631 (CH¼CH). 1H NMR (300 MHz, DMSO‑d6):
d 5.35 (d,
A mixture of compound 14 (0.37 gm, 1 mmol) and hydrazine
hydrate 99% (0.04 gm, 1 mmol) in absolute ethanol (20 mL) was
refluxed for 3 h where the product was then obtained by crystal-
lization from ethanol, Yellow precipitate, m.p. > 300 ꢃC, Yield, 66%,
IR (cmꢂ1): 3200 (NH2), 3132 (NH), 3059 (CH arom.), 2937 (CH
1H, J ¼ 8.1 Hz), 7.29e7.22 (m, 4H), 7.80 (dd, 1H, J ¼ 8.1, 12.5 Hz), 8.05
(d, 1H, J ¼ 2 Hz), 8.21 (d, 1H, J ¼ 2 Hz), 11.94 (d, 2H, J ¼ 12.5 Hz, 2NH,
D2O-exchangeable). 13C NMR (100 MHz, DSMO-d6):
d 29.96, 86.85,
115.49, 116.07, 120.10, 120.57, 128.19, 129.81, 130.64, 138.60, 138.93,
142.32, 143.75, 156.01, 159.28, 172.77. MS m/z: 455 (Mþ þ 2), 453
(Mþ). Anal. Calcd. for C16H10Br2ClN3O (456): C, 42.19; H, 2.21; N,
9.22, Found: C, 42.38; H, 2.08; N, 9.37.
aliph.), 1669 (C¼O). 1H NMR (400 MHz, DMSO‑d6):
d 4.60 (br s, 2H,
NH2, D2O-exchangeable), 5.20 (d, 1H, J ¼ 8 Hz), 7.68e7.73 (m, 1H),
8.13 (d, 1H, J ¼ 2.4 Hz), 8.23 (d, 1H, J ¼ 2.4 Hz), 12.15 (s, 1H, NH, D2O-
exchangeable), 12.60 (s, 1H, D2O-exchangeable). Anal. Calcd. For
4.1.10.6. 6,8-Dibromo-2-(2-(pyridin-2-ylamino)vinyl)quinazolin-
4(3H)-one (16f). Off white powder; Yield, 77%; m.p. 275 ꢃC, IR
(cmꢂ1): 3404, 3346 (NH), 3068 (CH arom.), 2933 (CH aliph.), 1685
C
10H8Br2N4O (360): C, 33.36; H, 2.24; N, 15.56, Found: C, 33.61; H,
2.32; N, 15.22.
(C¼O), 1622 (CH¼CH). 1H NMR (400 MHz, DMSO‑d6):
d 5.23 (d, 1H,
4.1.10. General method for synthesis of 6,8-dibromo-2-((E)-2-
(arylamino)vinyl)quinazolin-4(3H)-ones (16a-f)
A mixture of compound 14 (0.37 gm, 1 mmol) and the appro-
priate aniline (1 mmol) in ethanol was refluxed for 3 h to obtain the
compounds (16a-f).
J ¼ 8 Hz), 7.89e8.10 (m, 6H), 8.21 (d, 1H, J ¼ 2.4 Hz), 11.75 (s, 1H),
12.60 (s, 1H). MS m/z: 424 (Mþ þ 4), 423 (Mþ þ 3), 422 (Mþ þ 2),
peaks for bromine isotopes: (413, 411), (417, 415), (277, 275), (247,
245), (221, 219), (145, 143). Anal. Calcd. for C15H10Br2N4O (422): C,
42.68; H, 2.39; N, 13.27, Found: C, 42.92; H, 2.44; N, 13.43.
4.1.10.1. 6,8-Dibromo-2-(2-(phenylamino)vinyl)quinazolin-4(3H)-
one (16a). Yellow powder; Yield, 75%, m.p. > 300 ꢃC; IR (cmꢂ1):
3385 (NH), 3134 (NH), 3037 (CH arom.), 2922 (CH aliph.), 1664
4.1.11. 3-Amino-6,8-dibromo-2-methylquinazolin-4(3H)-one (17)
An equimolar mixture of compound 3 (0.319 gm, 1 mmol) and
hydrazine hydrate 99% (0.5 mL, 1 mmol) in 20 mL absolute ethanol
was refluxed for 12 h. Upon reaction completion, the mixture was
concentrated in vacuum where compound 17 was obtained as
white crystals upon recrystallization from ethanol and confirmed
(C¼O), 1669 (C¼C). 1H NMR (400 MHz, DMSO‑d6):
d 5.20 (d, 1H,
J ¼ 8.4 Hz), 7.03 (t, 1H, J ¼ 8 Hz), 7.30e7.39 (m, 4H), 7.83 (dd, J ¼ 8.4,
12.5 Hz, 1H), 8.10 (d, 1H, J ¼ 2.2 Hz), 8.32 (d, 1H, J ¼ 2.2 Hz), 11.65 (d,
1H, J ¼ 12.5 Hz), 12.25 (s, 1H, NH, D2O-exchangeable). MS m/z: 423
(Mþ þ 4), 421 (Mþ þ 2), 419 (Mþ). Anal. Calcd. for C16H11Br2N3O
(421): C, 45.64; H, 2.63; N, 9.98, Found: C, 45.78; H, 2.68; N, 10.14.
4.1.12. N'-(6,8-dibromo-2-methyl-4-oxoquinazolin-3(4H)-yl)-N,N-
dimethylformamidine (18)
4.1.10.2. 6,8-Dibromo-2-(2-(p-tolylamino)vinyl)quinazolin-4(3H)-
one (16b). Yellow powder, Yield, 70%, m.p. > 300 ꢃC; IR (cmꢂ1):
3446 (NH), 3132 (NH), 3051(CH arom.), 2970 (CH aliph.), 1672
Compound 17 (0.33 gm, 1 mmol) and DMF-DMA (1.2 mL,
1 mmol) were refluxed in xylene (10 mL) for 90 min. After cooling
and evaporating the solvent, large colourless needle crystals were
obtained. Yield, 77%; m.p. 170e172 ꢃC. IR (cmꢂ1): 3056 (CH arom.),
2934 (CH aliph.), 1668 (C¼O), 1622 (CH¼N). 1H NMR (300 MHz,
(C¼O), 1633 (C¼C). 1H NMR (400 MHz, DMSO‑d6):
d 2.26 (s, 3H),
5.15 (d,1H, J ¼ 8.4 Hz), 7.15 (d, 2H, J ¼ 8.8 Hz), 7.18 (d, 2H, J ¼ 8.8 Hz),
7.72 (dd, 1H, J ¼ 8.4, 1.5 Hz), 8.07 (d, 1H, J ¼ 2 Hz), 8.28 (d, 1H,
J ¼ 2 Hz), 11.61 (d, 1H, J ¼ 12.5 Hz), 12.18 (s, 1H). MS m/z (%): 437
(Mþ þ 4), 435 (Mþ þ 2), 433 (Mþ). Anal. Calcd. for C17H13Br2N3O
(435): C, 46.93; H, 3.01; N, 9.66, Found: C, 47.12; H, 3.05; N, 9.84.
DMSO‑d6):
d 2.48 (s, 3H), 2.96 (s, 6H), 7.90 (s, 1H), 8.04 (s, 1H), 8.15
(s, 1H). Mass m/z: 346 [Mþ þ 4 - N(CH3)2], 344 [Mþ þ 2 - N(CH3)2],
342 [Mþ ꢂ N(CH3)2], peaks for bromine isotopes: (290, 288), (278,
276), (263, 261), (225, 223), (196, 194), (155, 153). Anal. Calcd. for
C
12H12Br2N4O (388): C, 37.14; H, 3.12 N, 14.44, Found: C, 37.39, H,
4.1.10.3. 6,8-Dibromo-2-(2-((4-methoxyphenyl)amino)vinyl)quina-
zolin-4(3H)-one (16c). Yellow powder, Yield, 78%, m.p. > 300 ꢃC. IR
(cmꢂ1): 3400 (NH), 3132, 3048 (CH arom.), 2949 (CH aliph.), 1678
3.19, N, 14.47.
4.2. Biology
(C¼O), 1629 (CH¼CH). 1H NMR (400 MHz, DMSO‑d6):
d 3.72 (s, 3H),
5.11 (d, 1H, J ¼ 8.4 Hz), 6.93 (d, 2H, J ¼ 8.8 Hz), 7.23 (d, 2H,
J ¼ 8.8 Hz), 7.72 (dd, 1H, J ¼ 8.4, 12.5 Hz), 8.06 (d, 1H, J ¼ 2 Hz), 8.27
(d, 1H, J ¼ 2 Hz), 11.63 (d, 1H, J ¼ 12.5 Hz), 12.15 (s, 1H). MS m/z: 453
(Mþ þ 4), 451 (Mþ þ 2), 499 (Mþ). Anal. Calcd. for C17H13Br2N3O2
(451): C, 45.26; H, 2.9, N, 9.31, Found: C, 45.49; H, 2.9; N, 9.45.
4.2.1. Cytotoxic activity via SRB assay
MCF-7 human tumor cell line, (breast adenocarcinoma) was
grown as monolayer and routinely maintained in RPMI-1640 me-
dium supplemented with 5% heat inactivated FBS, 2 mM glutamine
and antibiotics (penicillin 100 U/ml, streptomycin 100 mg/ml), at
37 ꢃC in a humidified atmosphere containing 5% CO2. Exponentially
growing cells were obtained by plating 1.5 ꢄ 105 cells/ml for MCF-7
followed by 24 h of incubation. The effect of the vehicle solvent
(DMSO) on the growth of these cell lines was evaluated in all the
experiments by exposing untreated control cells to the maximum
concentration (0.5%) of DMSO used in each assay. The activity of the
compounds was evaluated using sulforhodamine B dye where cells
4.1.10.4. 6,8-Dibromo-2-(2-((4-(diethylamino)phenyl)amino)vinyl)
quinazolin-4(3H)-one
(16d). yellow
powder;
Yield,
80%,
m.p. > 300 ꢃC; IR (cmꢂ1): 3446 (NH), 3421 (NH), 3061 (CH arom.),
2972 (CH aliph.), 1683 (C¼O), 1627 (CH¼CH). 1H NMR (300 MHz,
DMSO‑d6):
d
1.06 (t, 6H, J ¼ 6.9 Hz), 3.3 (q, 4H, J ¼ 6.9 Hz), 5.06 (d,
1H, J ¼ 8.1 Hz), 6.69 (d, 2H, J ¼ 8.7 Hz), 7.13 (d, 2H, J ¼ 8.7 Hz), 7.68
(dd, 1H, J ¼ 8.1, 12.5 Hz), 8.05 (d, 1H, J ¼ 2.4 Hz), 8.25 (d,1H,
J ¼ 2.4 Hz), 11.68 (d, 1H, J ¼ 12.5 Hz, NH, D2O-exchangeable), 12.1 (s,
1H, NH D2O-exchangeable). MS m/z: 494 (Mþ þ 4), 492 (Mþ þ 2),
490 (Mþ), peaks for bromine isotopes: (449, 447), (238, 236), (195,
193), (93, 91). Anal. Calcd. for C20H20Br2N4O (492): C, 48.80; H, 4.10;
N, 11.38, Found: C, 49.03; H, 4.17; N, 11.61.
were treated with five different serial dilutions (up to 150 mM) of
the compounds for 48 h. Doxorubicin was used as a positive control
and tested in the same manner. The cytotoxicity of the compounds
were then determined using the SRB method as previously
described by Skehan et al. [53]. Similarly, compound 17 was tested
on the triple negative human tumor breast cancer cell MDA-MB-
231 and on the normal breast cell line MCF-10A.
4.1.10.5. 6,8-Dibromo-2-(2-((4-chlorophenyl)amino)vinyl)quinazo-
lin-4(3H)-one (16e). Yellow powder; Yield, 80%; m.p. > 300 ꢃC. IR
A-549 human lung cancer cell line were grown in DMEM sup-
plemented with 10% heat inactivated FBS, 50 units/ml of penicillin
13