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271
4.2.19. 8-Trifluoromethylquinazolin-4(3H)-one (19)
4.2.28. 2,5-Dimethylquinazolin-4(3H)-one (28)
3-Trifluoromethylanthranilic acid (1 g, 4.87 mmol) was used to
obtain 19 as yellowish white powder according to Scheme 1 (0.74 g,
6-Methylanthranilic acid (1 g, 6.62 mmol) was used to obtain 28
over two steps to yield white powder according to Scheme 2
(0.82 g, 71%); m.p. 248e251 ꢀC (lit. 257e258 ꢀC) [32]. 1H NMR
71%); m.p. 235e237 ꢀC [31]. 1H NMR (400 MHz, DMSO-d6)
d 12.63
(s, 1H), 8.39 (d, 1H, J ¼ 7.9 Hz) 8.27 (s, 1H), 8.20 (d, 1H, J ¼ 7.3 Hz),
(400 MHz, DMSO-d6)
(d, 1H, J ¼ 8.0 Hz), 7.17 (d, 1H, J ¼ 7.3 Hz), 2.75 (s, 3H), 2.29 (s, 3H).
d
11.97 (s, 1H), 7.57 (t, 1H, J ¼ 7.7 Hz), 7.36
7.65 (t, 1H, J ¼ 7.7 Hz).
4.2.20. 8-Methylquinazolin-4(3H)-one (20)
4.2.29. 2,6,8-Trimethylquinazolin-4(3H)-one (29)
3-Methylanthranilic acid (0.3 g, 1.98 mmol) was used to
obtain 20 as white crystals according to Scheme 1 (0.25 g,
78%); m.p. 249e252 ꢀC (lit. 247e249 ꢀC) [27]. 1H NMR
3,5-Dimethylanthranilic acid (1 g, 6.05 mol) was used to obtain
29 over two steps as white powder according to Scheme 2 (0.69 g,
60%); m.p. 263e265 ꢀC (lit. 266 ꢀC) [34]. 1H NMR (400 MHz, DMSO-
(400 MHz, DMSO-d6)
d
12.25 (s, 1H), 8.12 (s, 1H), 7.96 (s, 1H,
d6) d 11.86 (s, 1H), 7.42 (s, 1H), 7.32 (s, 1H), 2.28 (s, 3H), 2.14 (s, 3H),
J ¼ 7.8 Hz), 7.67 (d, 1H, J ¼ 7.2 Hz), 7.39 (t, 1H, J ¼ 7.6 Hz), 2.53
1.98 (s, 3H).
(s, 3H).
4.2.30. 8-Chloro-2-methylquinazolin-4(3H)-one (30)
4.2.21. 8-Nitroquinazolin-4(3H)-one (21)
3-Chloroanthranilic acid (1 g, 5.82 mmol) was used to obtain 30
over two steps as white crystals according to Scheme 2 (0.83 g,
3-Nitroanthranilic acid (1 g, 5.49 mmol) was used to obtain 21 as
yellow powder according to Scheme
1
(0.83 g, 79%); m.p.
73%); m.p. 247e250ꢀC [35]. 1H NMR (400 MHz, DMSO-d6)
d 12.43
240e244 ꢀC. (lit. 248e251 ꢀC) [27]. 1H NMR (400 MHz, DMSO-d6)
(s, 1H), 8.02 (d, 1H, J ¼ 7.6 Hz), 7.9 (d, 1H, J ¼ 7.2 Hz), 7.41 (t, 1H,
d
12.56 (s, 1H), 8.95 (s, 1H), 8.50 (d, 1H, J ¼ 7.8 Hz), 8.32 (m, 1H) 7.55
J ¼ 7.8 Hz), 2.39 (s, 3H); 13C NMR (100 MHz, DMSO-d6)
d 161.68,
(d, 1H, J ¼ 7.2 Hz).
155.96, 145.77, 134.87, 130.56, 126.60, 125.32, 122.82, 22.24.
4.2.22. 8-Aminoquinazolin-4(3H)-one (22)
4.2.31. 8-Amino-2-methylquinazolin-4(3H)-one (31)
8-Nitroquinazolin-4(3H)-one 21 (0.3 g, 1.56 mmol) was used to
obtain 22 as an off white powder according to Scheme 1 (0.18 g,
72%); m.p. 256e260 ꢀC (lit 261 ꢀC decomposed) [27]. 1H NMR
3-Nitroanthranilic acid (0.5 g, 2.74 mmol) was used to yield 31
after three steps as yellowish powder according to Scheme 2
(0.29 g, 60%); m.p. 226e230 ꢀC; 1H NMR (400 MHz, DMSO-d6)
(400 MHz, DMSO-d6)
d
12.09 (s, 1H), 7.97 (s, 1H), 7.22 (d, 1H,
d
12.04 (s, 1H), 7.19 (d, 1H, J ¼ 7.8 Hz), 7.11 (t, 1H, J ¼ 7.7 Hz), 6.93
J ¼ 6.5 Hz), 7.18 (t, 1H, J ¼ 7.7 Hz), 6.97 (d, 1H, J ¼ 7.4 Hz), 5.67
(d, 1H, J ¼ 7.6 Hz), 5.58 (bs, 2H), 2.35 (s, 3H); 13C NMR (100 MHz,
(bs, 2H); 13C NMR (100 MHz, DMSO-d6)
136.07, 127.66, 123.30, 116.04, 111.95.
d
161.53, 145.24, 142.84,
DMSO-d6) d 162.49, 151.77, 144.27, 136.47, 126.68, 121.19, 116.11,
112.19, 21.91; Anal. Calcd. for C9H9N3O1.3/5H2O: C, 58.12; H, 5.53; N,
22.59. Found: C, 58.34; H, 5.15; N, 22.26.
4.2.23. 6,7-Difluoroquinazolin-4(3H)-one (23)
4,5-Difluoroanthranilic acid (1 g, 5.77 mmol) was used to obtain
23 as tan powder according to Scheme 1 (0.77 g, 73%); m.p.
4.2.32. 2,8-Dimethylquinazolin-4(3H)-one (32)
3-Methylanthranilic acid (1 g, 6.61 mmol) was used to obtain 32
over two steps to yield white powder according to Scheme 2 (0.8 g,
69%); m.p. 250e252 ꢀC (lit. 252e253 ꢀC) [32]. 1H NMR (400 MHz,
252e255 ꢀC (lit. 257 ꢀC) [27]. 1H NMR (400 MHz, DMSO-d6)
d 12.27
(s, 1H), 8.07 (s, 1H), 7.96 (m, 1H), 7.69 (m, 1H).
DMSO-d6)
d
12.03 (s, 1H), 7.57 (t, 1H, J ¼ 7.7 Hz), 7.45 (d, 1H,
4.2.24. 6,8-Dimethylquinazolin-4(3H)-one (24)
J ¼ 8.0 Hz), 7.23 (d, 1H, J ¼ 7.3 Hz), 2.84 (s, 3H), 2.29 (s, 3H); 13C NMR
3,5-Dimethylanthranilic acid (1 g, 6.05 mmol) was used to
obtain 24 as white powder according to Scheme 1 (0.81 g, 77%);
m.p. 232e234 ꢀC (lit. 244e247 ꢀC) [31]. 1H NMR (400 MHz, DMSO-
(100 MHz, DMSO-d6) d 162.45, 153.50, 147.83, 135.04, 134.97,
125.60, 123.75, 120.93, 22.18, 17.74.
d6)
d
12.15 (s, 1H), 8.05 (s, 1H), 7.76 (s, 1H), 7.51 (s, 1H), 2.49 (s, 3H),
5. PARP-1 inhibition assay
2.39 (s, 3H).
Inhibitory action of the various quinazolin-4(3H)-one deriva-
tives towards PARP-1 was determined using the Universal Colori-
metric PARP Assay kit (Catalog # 4677-096-K; Trevigen, Inc.,
Gaithersburg, MD) according to the instructions provided by the
manufacturer. Stock solutions (1 mM) of the various test
compounds were made in dimethyl sulfoxide (DMSO) and were
then serially diluted to the required concentrations with distilled
4.2.25. 6,7-Dimethoxyquinazolin-4(3H)-one (25)
4,5-Dimethoxyanthranilic acid (1 g, 5.07 mmol) was used to
obtain 25 as off-white powder according to Scheme 1 (0.76 g, 73%);
m.p. 281e283 ꢀC (lit. 270 ꢀC) [27]. 1H NMR (400 MHz, DMSO-d6)
d
12.08 (s, 1H), 7.99 (s, 1H), 7.44 (s, 1H), 7.13 (s, 1H), 3.90 (s, 3H), 3.87
(s, 3H).
water. For the assay, to each strip well was added 50 mL/well of 1X
4.2.26. 5-Fluoro-2-methylquinazolin-4(3H)-one (26)
PARP buffer to rehydrate the histones and incubated at room
temperature for 30 min 1X PARP buffer was removed from the
wells by tapping the strip wells on clean paper towels. To each well,
6-Fluoroanthranilic acid (1 g, 6.44 mmol) was used to obtain 26
over two steps as tan crystals according to Scheme 2 (0.83 g, 72%);
m.p. 247e250 ꢀC (lit. 249e252 ꢀC) [32]. 1H NMR (400 MHz, DMSO-
10
(providing 0.5 U/well) was added, followed by a 10 min incubation.
Then 25 L of PARP Cocktail (consisting of biotinylated NAD, acti-
mL of the inhibitor solution and 15 mL of diluted PARP-1 enzyme
d6)
d
12.4 (s, 1H), 7.88 (d, 1H, J ¼ 7.8 Hz), 7.63 (t, 1H, J ¼ 8.9 Hz), 7.43
(m, 1H), 2.37 (s, 3H).
m
vated DNA in Tris-Cl pH 8.0, and EDTA) was added to each of the
wells. 3-AB was used as a positive control. The strip wells were
incubated at room temperature for 60 min. The strip wells were
4.2.27. 5-Chloro-2-methylquinazolin-4(3H)-one (27)
6-Chloroanthranilic acid (1 g, 5.84 mmol) was used to
obtain 27 over two steps to yield white powder according to
Scheme 2 (0.82 g, 72%); m.p. 246e247 ꢀC (lit. 288e290 ꢀC)
then washed 2X (200
ered saline (PBS: Na2HPO4, NaH2PO4, and NaCl), followed by 2X
with PBS (200 L/well). Then, 50 L of 500 times diluted Strep-HRP
mL/well) with 0.1% Triton in phosphate buff-
[33]. 1H NMR (400 MHz, DMSO-d6)
d
12.4 (s, 1H), 8.03
m
m
(d, 1H, J ¼ 7.9 Hz), 7.91 (d, 1H, J ¼ 7.8 Hz), 7.42 (t, 1H,
with blocking solution (1X) Strep Diluent was added to each well,
and the strips were further incubated at room temperature for
J ¼ 7.8 Hz), 2.39 (s, 3H).