Antitumor agents 281. Design, synthesis, and biological activity of substituted 4-amino-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one analogs (ATBO) as potent in vitro anticancer agents

Article abstract of DOI:10.1016/j.bmcl.2010.10.074

In our exploration of new biologically active chemical entities, we designed and synthesized a novel class of antitumor agents, substituted 4-amino-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (ATBO) analogs. We evaluated their cytotoxic activity against seven human tumor cell lines from different tissues, and established preliminary structure-activity relationships (SAR). All analogs, except 8, 9, and 25-27, displayed potent tumor cell growth inhibitory activity. Especially, compounds 15 and 33 with a 4-methoxyphenyl group at position C-4 were extremely potent with ED₅₀ values of 0.008-0.064 and 0.035-0.32 μM, respectively. Compound 15 was the most potent analog compared with structurally related neo-tanshinlactone (e.g., 1) and 4-amino-2H-benzo[h]chromen-2-one (ABO, e.g., 4) analogs, and thus merits further exploration as an anti-cancer drug candidate.

Full text of DOI:10.1016/j.bmcl.2010.10.074

Bioorganic & Medicinal Chemistry Letters 21 (2011) 546–549
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Antitumor agents 281. Design, synthesis, and biological activity of substituted
4-amino-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one analogs (ATBO)
as potent in vitro anticancer agents
Yizhou Dong a, Kyoko Nakagawa-Goto a, Chin-Yu Lai a, Susan L. Morris-Natschke a, Kenneth F. Bastow b,
Kuo-Hsiung Lee a,c,
⇑
a Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599-7568, USA
b Division of Medicinal Chemistry and Natural Products, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599-7568, USA
c Chinese Medicine Research and Development Center, China Medical University, Taichung, Taiwan
a r t i c l e i n f o
a b s t r a c t
Article history:
In our exploration of new biologically active chemical entities, we designed and synthesized a novel class
of antitumor agents, substituted 4-amino-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (ATBO) ana-
logs. We evaluated their cytotoxic activity against seven human tumor cell lines from different tissues,
and established preliminary structure–activity relationships (SAR). All analogs, except 8, 9, and 25–27,
displayed potent tumor cell growth inhibitory activity. Especially, compounds 15 and 33 with a
4-methoxyphenyl group at position C-4 were extremely potent with ED50 values of 0.008–0.064 and
Received 18 June 2010
Revised 14 October 2010
Accepted 15 October 2010
Available online 17 November 2010
Keywords:
0.035–0.32 lM, respectively. Compound 15 was the most potent analog compared with structurally
4-Amino-7,8,9,10-tetrahydro-2H-
benzo[h]chromen-2-ones (ATBO)
Cytotoxic activity
related neo-tanshinlactone (e.g., 1) and 4-amino-2H-benzo[h]chromen-2-one (ABO, e.g., 4) analogs, and
thus merits further exploration as an anti-cancer drug candidate.
Ó 2010 Elsevier Ltd. All rights reserved.
Neo-tanshinlactone
One of the most challenging areas of research in both industry
and academia is the discovery and development of new medi-
cines.1,2 In 2009, 103 new drugs were approved by the FDA’s
Center for Drug Evaluation and Research (CDER).3 Nineteen new
molecular entities (NMEs) and six biologics license applications
(BLAs) were filed among these approvals.3 The pharmaceutical
industry’s demand for new leads with new scaffolds has never
been greater.4 These facts prompted us to design and discover
new biologically active chemical entities.
Previously, our group successfully developed new cytotoxic
chemical entities, including neo-tanshinlactone (1, Fig. 1) and its
4-ethyl analog 2,5,6 for treating breast cancer, and these com-
pounds are now in extended preclinical study. Structural simplifi-
cation and optimization is a powerful tool for analog design and
lead exploration. For example, this strategy was applied to the nat-
ural product halichondrin B, a potent mitotic inhibitor, which led
to a new therapeutic medicine, eribulin mesylate.7 In our continu-
ous exploration of new chemical entities, we also designed and
developed several additional series of novel anticancer agents
according to this strategy. These agents include 2-(furan-2-yl)
naphthalen-1-ol (FNO),8 6-phenyl-4H-furo[3,2-c]pyran-4-one (AFPO),9
tetrahydronaphthalene-1-ol (TNO),10 and 4-amino-2H-benzo[h]-
chromen-2-one (ABO, 3, Fig. 1)11 analogs. Lead compounds showed
potent antitumor activity and different tumor tissue type selectiv-
ity. Braccio et al. first reported four compounds with the ABO scaf-
fold and their cytotoxic activity against Ehrlich ascites tumor
cells.12 We also designed and explored this scaffold based on our
studies of neo-tanshinlactone analogs (1 and 2). Compound 4
showed potent and broad antitumor activity compared with 1
and 2.11 Structure–activity relationship (SAR) studies on 3 indi-
cated that (1) secondary amine (R2 or R3 = H) is preferred over ter-
tiary amine (R2 and R3 – H), (2) bulky groups are favored at R2/R3
position, (3) 30-bromophenyl group can cause dramatic loss of
potency, and (4) hydrogen is better than an ethyl group at R1 posi-
tion. Our prior studies also suggested that a non-aromatic ring can
greatly affect the antitumor activity and cancer cell line selectiv-
ity.10 Consequently, we have now designed scaffold 5 with a
non-aromatic five- or six-membered A-ring ( Fig. 1). Different
amino (R2/R3) and A-ring (R1) substituents were incorporated to
establish SAR and identify potent analogs. This Letter reports the
design, synthesis, and biological activity of 4-amino-7,8,9,10-tetra-
hydro-2H-benzo[h]chromen-2-one, (ATBO) analogs.
All target compounds 8–27, 32, and 33 were synthesized from
the related 4-hydroxy compounds, 6, 28, and 29, respectively,
according to the methods reported before (Scheme 1). Chlorides
7, 30, and 31 were synthesized by treatment of 6, 28, and 29,
⇑
Corresponding author. Tel.: +1 919 962 0066; fax: +1 919 966 3893.
E-mail address: khlee@unc.edu (K.-H. Lee).
0960-894X/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2010.10.074

Y. Dong et al. / Bioorg. Med. Chem. Lett. 21 (2011) 546–549
547
O
O
O
C
OMe
O
O
O
O
B
O
C
4
D
O
4
NR2R3
NR2R3
n
N
A
B
A
A
H
R1
7
4
R
R1
3
5
4
R = Me: Neo-tanshinlatone (1)
R = Et: 4-Ethylneo-tanshinlatone (2)
Figure 1. Structures of neo-tanshinlactone (1), 4-ethyl neo-tanshinlactone (2), previously reported scaffold 3 and its analog 4, and newly designed scaffold 5.
respectively, with POCl3.11,12 Various amino derivatives, 8–27, 32,
and 33, were newly prepared by substitution reactions of 7, 30,
and 31 with different amines according to reported
procedures.12,13
All synthesized analogs 8–27, 32, and 33 were tested for
in vitro cytotoxic activity against a panel of human tumor cell lines
according to previously published methods (Table 1).8,14,15 Cell
lines included A549 (non small cell lung cancer), DU145 (prostate
cancer cell line), KB (nasopharyngeal carcinoma), KB-VIN (vincris-
tine-resistant MDR KB subline), MDA-MB-231 (estrogen receptor
negative breast cancer), SK-BR-3 (estrogen receptor negative,
HER2 over-expressing breast cancer), and ZR-75-1 (estrogen recep-
tor positive breast cancer).
reduced or no activity against all tested cell lines. These findings
suggested that a cyclic group is better than a linear group for cyto-
toxic activity, and a bulky amino group is favored. The tertiary
amines 25–27 were not active, regardless of cyclic or linear amino
groups; thus, a secondary amine is crucial for antitumor activity.
The above results are consistent with our previous studies for
ABO analogs.10 Interestingly, 8 and 9 showed unique selectivity
against ZR-75-1 compared with other cell lines tested, although
the inhibitory potency was only moderate. In addition, 11 with a
cyclohexyl group showed similar potency to 12 with a phenyl
group, which indicated that aromaticity of the amino substituent
is not an essential factor.
Regarding aromatic R2/R3 substituents, we explored different
groups at the 20, 30, and 40 positions. Generally, all aromatic deriv-
atives 12–24 showed significant cytotoxicity against the human
tumor cell lines tested. Among them, 40-MeO 15 was the most po-
tent analog against all tested tumor cell lines (ED50 values of
Regarding ATBO analogs with aliphatic R2/R3 amino substitu-
ents, 11 with a cyclohexyl group showed greater activity than
the methyl, propyl, and cyclopropyl derivatives 8–10. Analog 10
with a cyclopropyl group displayed tumor cell line selectivity
against KB, KB-VIN, and ZR-75-1, while 8 and 9 showed greatly
0.008–0.064
lM). It was 2- to 3-fold more potent than the related
O
O
O
O
O
O
b for 8-11,
Cl and 25-27
NR2R3
OH
a
n
n
n
c for 12-24
and 32-33
R1 R1
R1 R1
R1 R1
6: R1 = H, n = 1
28: R1 = H, n = 0
29: R1 = Me, n = 1
7: R1 = H, n = 1
30: R1 = H, n = 0
31: R1 = Me, n = 1
8-27: R1 = R2 = H, n = 1, see R3 below
32: R1 = R2 = H, n = 0, R3 = p-OMeC6H5
33: R1 = Me, R2 = H, n = 1, R3 = p-OMeC6H5
R3=
Me
10
8
9
11
1'
4'
OMe
F
Br
Me
Et
15, 32-33
17
24
14
16
13
12
OMe
Br
Me
Me
MeO
O
Br
21
23
20
22
19
18
O
O
O
O
O
N
N
N
O
26
27
25
Scheme 1. Reagents and conditions: (a) POCl3, Et3N, reflux, 1 h; (b) aliphatic amines, EtOH, reflux, 2 h; (c) aromatic amines, ethylene glycol, 160 °C, 1 h.

548
Y. Dong et al. / Bioorg. Med. Chem. Lett. 21 (2011) 546–549
Table 1
Cytotoxicity of 8–27, 32–33 against human tumor cell line panela
Compd
KB
>30
0.11 0.01
>30
KB-VIN
A549
DU145
SKBR-3
ZR-75-1
MDA-MB-231
1
4
8
>30
0.13 0.02
>30
>30
0.17 0.03
>30
>30
0.11 0.02
>30
0.95
0.13 0.01
>30
0.95
>30
0.025 0.003
>30
>30
>30
0.008 0.003
7.86 0.22
7.04 0.19
2.16 0.12
1.11 0.17
2.51 0.38
1.28 0.39
10.34 1.25
0.024 0.002
14.24 0.32
10.00 1.08
2.43 0.13
0.69 0.03
0.18 0.02
1.84 0.10
1.53 0.09
0.49 0.05
1.26 0.06
17.06 1.34
18.37 1.06
19.30 1.05
0.39 0.07
0.32 0.06
9
>30
>30
>30
>30
>30
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
32
33
2.24 0.26
1.23 0.12
1.15 0.43
0.91 0.29
0.16 0.03
0.037 0.005
1.04 0.26
0.63 0.16
0.80 0.20
0.87 0.21
0.20 0.06
0.24 0.02
0.22 0.05
0.83 0.05
0.48 0.16
20.44 3.80
>30
3.28 1.24
1.29 0.42
2.01 0.57
1.36 0.46
0.12 0.02
0.046 0.002
1.02 0.68
19.59 10.48
2.00 0.14
1.53 0.50
1.64 0.71
0.15 0.03
0.049 0.005
1.02 0.36
0.53 0.20
1.14 0.32
1.08 0.36
0.16 0.05
0.24 0.02
0.25 0.02
1.52 0.10
0.79 0.21
26.41 1.96
>30
8.37 2.22
1.21 0.01
1.35 0.69
1.52 0.69
0.16 0.02
0.038 0.005
0.96 0.38
0.51 0.20
2.43 1.32
0.81 0.23
0.11 0.03
0.15 0.04
0.22 0.06
1.29 0.33
0.50 0.11
15.86 1.29
>30
8.76 2.57
1.49 0.15
1.33 0.61
1.29 0.73
0.44 0.28
0.064 0.027
1.23 0.41
0.76 0.22
5.61 4.63
0.96 0.12
0.41 0.15
0.51 0.28
0.31 0.15
1.02 0.17
0.86 0.26
>30
>30
>30
27.54 1.97
14.11 0.63
0.008 0.002
>30
6.76 0.54
7.54 1.64
7.48 0.31
0.13 0.01
3.87 0.13
3.52 0.16
4.59 0.54
3.08 0.44
>30
0.52
0.01
2.41 1.30
0.96 0.27
0.20 0.06
0.18 0.02
0.16 0.01
1.08 0.17
0.33 0.004
19.58 4.60
>30
>30
>30
>30
0.27 0.04
0.23 0.02
>30
0.11 0.02
0.035 0.02
23.52 9.78
0.10 0.03
0.044 0.01
>30
0.13 0.01
0.049 0.001
>30
0.090 0.01
0.043 0.01
27.90 3.39
0.15 0.03
0.037 0.02
a
Mean ED50 SD (lM), from 2 or more independent tests.
ABO analog 4 against all cell lines, except ZR-75-1. Importantly, 15
also exhibited the highest cytotoxicity against MDA-MB-231 (ER
negative breast cancer) compared with other cell lines. Analogs
10–13, 19, 23, and 24 were less potent against MDA-MB-231 and
14, 16, 21, 22 were less potent against both MDA-MB-231 and
ZR-75-1 compared with other tested cell lines, which indicated dif-
ferent cancer cell line selectivity among ATBO analogs.
We further investigated the effect of ring-A. Analogs 15 and 32,
with an unsubstituted six and five-membered ring, respectively, as
well as analog 33, with a six-membered ring-A with gem-dimethyl
substitution, displayed significant inhibition against all tested
human tumor cell lines, but different selectivity against tumor cell
lines from different tissues. Against KB, KB-VIN, A549, DU145, and
SKBR-3, 15 and 33 were at least 2-fold more potent than 32.
References and notes
1. Bleicher Konrad, H.; Bohm, H.-J.; Muller, K.; Alanine Alexander, I. Nat. Rev. Drug
Disc. 2003, 2, 369.
2. Vallance, P.; Williams, P.; Dollery, C. Clin. Pharmacol. Ther. 2010, 87, 525.
3. Hughes, B. Nat. Rev. Drug Disc. 2010, 9, 89.
4. Crommelin, D.; Stolk, P.; Besancon, L.; Shah, V.; Midha, K.; Leufkens, H. Nat. Rev.
Drug Disc. 2010, 9, 99.
5. Wang, X.; Bastow, K. F.; Sun, C. M.; Lin, Y. L.; Yu, H. J.; Don, M. J.; Wu, T. S.;
Nakamura, S.; Lee, K. H. J. Med. Chem. 2004, 47, 5816.
6. Wang, X.; Nakagawa-Goto, K.; Bastow, K. F.; Don, M. J.; Lin, Y. L.; Wu, T. S.; Lee,
K. H. J. Med. Chem. 2006, 49, 5631.
7. Kim, D. S.; Dong, C. G.; Kim, J. T.; Guo, H.; Huang, J.; Tiseni, P. S.; Kishi, Y. J. Am.
Chem. Soc. 2009, 131, 15636.
8. Dong, Y.; Shi, Q.; Liu, Y.-N.; Wang, X.; Bastow, K. F.; Lee, K.-H. J. Med. Chem.
2009, 52, 3586.
9. Dong, Y.; Shi, Q.; Nakagawa-Goto, K.; Wu, P.-C.; Morris-Natschke, S. L.; Brossi,
A.; Bastow, K. F.; Lang, J.-Y.; Hung, M.-C.; Lee, K.-H. Bioorg. Med. Chem. 2010, 18,
803.
10. Dong, Y.; Shi, Q.; Nakagawa-Goto, K.; Wu, P. C.; Bastow, K. F.; Morris-Natschke,
S. L.; Lee, K. H. Bioorg. Med. Chem. Lett. 2009, 19, 6289.
11. Dong, Y.; Nakagawa-Goto, K.; Lai, C. Y.; Morris-Natschke, S. L.; Bastow, K. F.;
Lee, K. H. Bioorg. Med. Chem. Lett. 2010, 20, 4085.
12. Di Braccio, M.; Grossi, G.; Roma, G.; Marzano, C.; Baccichetti, F.; Simonato, M.;
Bordin, F. Farmaco 2003, 58, 1083.
13. Alberola, A.; Alvaro, R.; Ortega, A. G.; Sadaba, M. L.; Sanudo, M. C. Tetrahedron
1999, 55, 13211.
14. Solubility of 12–14 and 16–18 in DMSO is not very great. Work is ongoing to
solve the solubility issue and results will be reported in due course.
15. Spectroscopic data. 4-(methylamino)-7,8,9,10-tetrahydro-2H-benzo[h]chromen-
2-one (8): 1H NMR (400 MHz, CDCl3): d 7.16 (d, 1H, J = 8.4 Hz, Ar-H), 6.96 (d,
1H, J = 8.4 Hz, Ar-H), 5.28 (s, 2H, NH & 3-H), 3.00 (d, 3H, J = 4.8 Hz, NCH3), 2.90
(t, 2H, J = 6.0 Hz, 10-H), 2.83 (t, 2H, J = 6.0 Hz, 7-H), 1.82 (m, 4H, 8 & 9-H). MS m/
z 228 (M+ꢀ1). 4-(propylamino)-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one
(9): 1H NMR (400 MHz, CDCl3): d 7.18 (d, 1H, J = 8.0 Hz, Ar-H), 6.96 (d, 1H,
J = 8.0 Hz, Ar-H), 5.28 (s, 1H, 3-H), 5.19 (br s, 1H, NH), 3.22 (q, 2H, J = 5.2 Hz,
NCH2), 2.90 (t, 2H, J = 6.0 Hz, 10-H), 2.82 (t, 2H, J = 6.0 Hz, 7-H), 1.78 (m, 6H, 8, 9
& 20-H), 1.04 (t, 3H, J = 7.2 Hz, 30-H). MS m/z 258 (M++1). 4-(cyclopropylamino)-
7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (10): 1H NMR (400 MHz,
CDCl3): d 7.10 (d, 1H, J = 8.4 Hz, Ar-H), 6.94 (d, 1H, J = 8.0 Hz, Ar-H), 5.72 (s,
1H, 3-H), 5.41 (br s, 1H, NH), 2.90 (t, 2H, J = 5.6 Hz, 10-H), 2.83 (t, 2H, J = 5.6 Hz,
7-H), 2.58 (m, 1H, NCH), 1.83 (m, 4H, 8 & 9-H), 0.91 (dd, 2H, J = 5.6, 5.2 Hz,
NCHCH2), 0.68 (dd, 2H, J = 5.2, 4.4 Hz, NCHCH2). MS m/z 254 (M+ꢀ1). 4-
(cyclohexylamino)-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (11): 1H NMR
(400 MHz, CDCl3): d 7.15 (d, 1H, J = 8.0 Hz, Ar-H), 6.95 (d, 1H, J = 8.4 Hz, Ar-H),
5.31 (s, 1H, 3-H), 5.01 (d, 1H, J = 5.6 Hz, NH), 3.40 (m, 1H, 10-H), 2.90 (t, 2H,
J = 6.0 Hz, 10-H), 2.81 (t, 2H, J = 6.0 Hz, 7-H), 2.12 (m, 2H, 20 & 60-H), 1.78 (m,
6H, 8, 9 & 20 & 60-H), 1.28 (m, 6H, 30 & 40& 50-H). MS m/z 298 (M++1). 4-
phenylamino-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (12): 1H NMR
(400 MHz, DMSO-d6): d 9.20 (br s, 1H, NH), 7.96 (d, 1H, J = 8.2 Hz, Ar-H), 7.48
(dd, 1H, J = 8.2 and 7.4 Hz, Ar-H), 7.36 (d, 1H, J = 8.2 Hz, Ar-H), 7.36 (d, 1H,
Against ZR-75-1 and MDA-MB-231, 15 (ED50 0.024 and 0.008 lM,
respectively) showed much higher activity as compared with 32
and 33. These results together with our previous findings indicated
that a non-aromatic ring-A may lead to changes in both potency
and cancer cell line selectivity of certain analogs. The size and iden-
tity of ring-A substituents are also important factors.
In conclusion, our structural modification and optimization
resulted in a novel class of in vitro anti-cancer agents, ATBO. The
results indicated that the non-aromatic ring-A of 5 is critical to
both potency and cancer cell line selectivity. Based on this study,
the preliminary SAR findings for the ATBO class were similar to
those with ABO analogs. (1) Secondary amine (R2 or R3 = H) is pre-
ferred over tertiary amine (R2 and R3 – H), (2) bulky groups are fa-
vored at R2/R3 position, (3) aromaticity is not required at R2/R3
position, and (4) non-aromatic ring-A can increase potency and
cancer cell line selectivity for certain analogs, such as 15. Com-
pound 15 was the most potent analog (ED50 values of 0.008–
0.064 lM) among all ABO and ATBO derivatives, and thus, is a
promising new lead compound for further development toward a
potential clinical trials candidate.
Acknowledgment
This work was supported by NIH Grant CA-17625 from the Na-
tional Cancer Institute, awarded to K.H. Lee.

Y. Dong et al. / Bioorg. Med. Chem. Lett. 21 (2011) 546–549
549
J = 7.4 Hz, Ar-H), 7.28 (dd, 1H, J = 7.4 & 7.2 Hz, Ar-H), 7.12 (d, 1H, J = 8.2 Hz, Ar-
H), 5.27 (s, 1H, 3-H), 2.86–2.74 (m, 4H, 7 &10-H), 1.85–1.72 (m, 4H, 8 & 9-H).
MS m/z 292 (M++1). 4-[(40-methylphenyl)amino]-7,8,9,10-tetrahydro-2H-
benzo[h]chromen-2-one (13): 1H NMR (400 MHz, DMSO-d6): d 9.14 (br s, 1H,
NH), 7.95 (d, 1H, J = 8.3 Hz, Ar-H), 7.28 (d, 2H, J = 8.2 Hz, Ar-H), 7.23 (d, 2H,
J = 8.2 Hz, Ar-H), 5.19 (s, 1H, 3-H), 2.86–2.74 (m, 4H, 7 &10-H), 2.34 (s, 3H, Ar-
H), 7.36 (t, 1H, J = 7.7 Hz, Ar-H), 7.19–7.08 (m, 3H, Ar-H), 5.26 (s, 1H, 3-H), 2.86–
2.74 (m, 4H, 7 &10-H), 2.36 (s, 3H, Ar-CH3), 1.85–1.72 (m, 4H, 8 & 9-H). MS m/z
306
(M++1).
4-[(30-methoxyphenyl)amino]-7,8,9,10-tetrahydro-2H-
benzo[h]chromen-2-one (22): 1H NMR (400 MHz, DMSO-d6): d 9.16 (br s, 1H,
NH), 7.94 (d, 1H, J = 8.4 Hz, Ar-H), 7.38 (t, 1H, J = 8.1 Hz, Ar-H), 7.11 (d, 1H,
J = 8.4 Hz, Ar-H), 6.98–6.92 (m, 1H, Ar-H), 6.92–6.89 (m, 1H, Ar-H), 6.85 (dd,
1H, J = 8.1 and 2.5 Hz, Ar-H), 5.35 (s, 1H, 3-H), 3.79 (s, 3H, OCH3), 2.86–2.74 (m,
CH3), 1.84–1.71 (m, 4H,
8
&
9-H). MS m/z 306 (M++1). 4-[(40-
ethylphenyl)amino]-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (14): 1H
NMR (400 MHz, DMSO-d6): d 9.14 (br s, 1H, NH), 7.95 (d, 1H, J = 8.4 Hz, Ar-
H), 7.31 (d, 2H, J = 8.4 Hz, Ar-H), 7.25 (d, 2H, J = 8.4 Hz, Ar-H), 7.11 (d, 1H,
J = 8.4 Hz, Ar-H), 5.20 (s, 1H, 3-H), 2.86–2.73 (m, 4H, 7 &10-H), 2.64 (q, 2H,
J = 7.5 Hz, Ar-CH2CH3), 1.84–1.72 (m, 4H, 8 & 9-H), 1.21 (t, 3H, J = 7.5 Hz, Ar-
CH2CH3). MS m/z 320 (M++1). 4-((40-methoxyphenyl)amino)-7,8,9,10-tetrahydro-
2H-benzo[h]chromen-2-one (15): 1H NMR (400 MHz, DMSO-d6): d 9.09 (br s, 1H,
NH), 7.94 (d, 1H, J = 8.8 Hz, Ar-H), 7.27 (d, 2H, J = 8.0 Hz, Ar-H), 7.10 (d, 1H,
J = 8.0 Hz, Ar-H), 7.04 (d, 2H, J = 8.0 Hz, Ar-H), 5.05 (s, 1H, 3-H), 3.79 (s, 3H,
OCH3), 2.82 (t, 2H, J = 5.6 Hz, 10-H), 2.76 (t, 2H, J = 5.6 Hz, 7-H), 1.78 (m, 4H, 8 &
9-H). MS m/z 320 (M+ꢀ1). 4-[(40-fluorophenyl)amino]-7,8,9,10-tetrahydro-2H-
benzo[h]chromen-2-one (16): 1H NMR (400 MHz, DMSO-d6): d 9.18 (br s, 1H,
NH), 7.93 (d, 1H, J = 8.2 Hz, Ar-H), 7.42–7.36 (m, 2H, Ar-H), 7.35–7.28 (m, 2H,
Ar-H), 7.12 (d, 1H, J = 8.2 Hz, Ar-H), 5.16 (s, 1H, 3-H), 2.86–2.73 (m, 4H, 7 &10-
H), 1.85–1.71 (m, 4H, 8 & 9-H). MS m/z 310 (M++1). 4-[(40-bromophenyl)amino]-
7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (17): 1H NMR (400 MHz, DMSO-
d6): d 9.21 (br s, 1H, NH), 7.92 (d, 1H, J = 8.3 Hz, Ar-H), 7.68–7.62 (m, 2H, Ar-H),
7.36–7.31 (m, 2H, Ar-H), 7.12 (d, 1H, J = 8.3 Hz, Ar-H), 5.34 (s, 1H, 3-H), 2.86–
2.74 (m, 4H, 7 &10-H), 1.85–1.72 (m, 4H, 8 & 9-H). MS m/z 368 and 370 (1:1,
M+ꢀ1). 4-[(20-methylphenyl)amino]-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-
one (18): 1H NMR (400 MHz, DMSO-d6): d 9.10 (br s, 1H, NH), 7.96 (d, 1H,
J = 8.2 Hz, Ar-H), 7.44–7.39 (m, 1H, Ar-H), 7.36–7.31 (m, 2H, Ar-H), 7.29–7.24
(m, 1H, Ar-H), 7.12 (d, 1H, J = 8.2 Hz, Ar-H), 4.54 (s, 1H, 3-H), 2.86–2.74 (m, 4H,
7 &10-H), 2.18 (s, 3H, Ar-CH3), 1.85–1.72 (m, 4H, 8 & 9-H). MS m/z 306 (M++1).
4-[(20-methoxyphenyl)amino]-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one
(19): 1H NMR (400 MHz, DMSO-d6): d 8.90 (br s, 1H, NH), 7.96 (d, 1H, J = 8.2 Hz,
Ar-H), 7.42–7.34 (m, 1H, Ar-H), 7.32–7.26 (m, 1H, Ar-H), 7.20 (d, 1H, J = 8.2 Hz,
Ar-H), 7.10 (d, 1H, J = 8.2 Hz, Ar-H), 7.09–7.05 (m, 1H, Ar-H), 4.68 (s, 1H, 3-H),
3.79 (s, 3H, OCH3), 2.96–2.72 (m, 4H, 7 &10-H), 1.86–1.70 (m, 4H, 8 & 9-H). MS
4H, 7 &10-H), 1.85–1.72 (m, 4H, 8 &
9-H). MS m/z 322 (M++1). 4-[(30-
bromophenyl)amino]-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (23): 1H
NMR (400 MHz, DMSO-d6): d 9.24 (br s, 1H, NH), 7.91 (d, 1H, J = 8.2 Hz, Ar-
H), 7.48–7.59–7.56 (m, 1H, Ar-H), 7.40 (m, 3H, Ar-H), 7.13 (d, 1H, J = 8.2 Hz, Ar-
H), 5.39 (s, 1H, 3-H), 2.86–2.74 (m, 4H, 7 &10-H), 1.85–1.72 (m, 4H, 8 & 9-H).
MS m/z 368 and 370 (1:1, M+ꢀ1). 4-(naphthalen-1-ylamino)-7,8,9,10-
tetrahydro-2H-benzo[h]chromen-2-one (24): 1H NMR (400 MHz, DMSO-d6): d
9.54 (br s, 1H, NH), 8.13 (d, 1H, J = 8.2 Hz, Ar-H), 8.05 (d, 1H, J = 7.4 Hz, Ar-H),
8.01 (d, 1H, J = 8.2 Hz, Ar-H), 7.81 (d, 1H, J = 8.2 Hz, Ar-H), 7.65 (dd, 1H, J = 8.2
and 7.4 Hz, Ar-H), 7.64–7.53 (m, 3H, Ar-H), 7.18 (d, 1H, J = 8.2 Hz, Ar-H), 4.50 (s,
1H, 3-H), 2.90–2.75 (m, 4H, 7 &10-H), 1.86–1.74 (m, 4H, 8 & 9-H). MS m/z 342
(M++1). 4-(dipropylamino)-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (25):
1H NMR (400 MHz, CDCl3):
d 7.37 (d, 1H, J = 8.4 Hz, Ar-H), 6.94 (d, 1H,
J = 8.4 Hz, Ar-H), 5.59 (s, 1H, 3-H), 3.27 (t, 4H, J = 6.0 Hz, N(CH2)2), 2.91 (t, 2H,
J = 5.6 Hz, 10-H), 2.82 (t, 2H, J = 5.6 Hz, 7-H), 1.83 (m, 4H, 8 & 9-H), 1.68 (m, 4H,
N(CH2 CH2 CH3)2), 0.90 (t, 6H, J = 7.6 Hz, N(CH2 CH2 CH3)2). MS m/z 300 (M++1).
4-(piperidin-1-yl)-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (26): 1H NMR
(400 MHz, CDCl3): d 7.32 (d, 1H, J = 8.0 Hz, Ar-H), 6.94 (d, 1H, J = 8.4 Hz, Ar-H),
5.64 (s, 1H, 3-H), 3.20 (t, 4H, J = 5.6 Hz, N(CH2)2), 2.90 (t, 2H, J = 5.6 Hz, 10-H),
2.82 (t, 2H, J = 5.6 Hz, 7-H), 1.81 (m, 8H, 8 & 9 & 30 & 50-H), 1.72 (m, 2H, NCH2
CH2 CH2). MS m/z 284 (M++1). 4-morpholino-7,8,9,10-tetrahydro-2H-
benzo[h]chromen-2-one (27): 1H NMR (400 MHz, CDCl3):
d 7.32 (d, 1H,
J = 8.4 Hz, Ar-H), 6.96 (d, 1H, J = 8.4 Hz, Ar-H), 5.69 (s, 1H, 3-H), 3.92 (t, 4H,
J = 4.8 Hz, O(CH2)2), 3.23 (t, 4H, J = 4.8 Hz, N(CH2)2), 2.90 (t, 2H, J = 5.6 Hz, 10-
H), 2.83 (t, 2H, J = 5.6 Hz, 7-H), 1.83 (m, 4H, 8 & 9-H). MS m/z 286 (M++1). 4-((40-
methoxyphenyl)amino)-8,9-dihydrocyclopenta[h]chromen-2(7H)-one (32): 1H
NMR (400 MHz, DMSO-d6): d 9.13 (br s, 1H, NH), 8.00 (d, 1H, J = 8.0 Hz, Ar-
H), 7.27 (m, 3H, Ar-H), 7.04 (d, 2H, J = 8.4 Hz, Ar-H), 5.04 (s, 1H, 3-H), 3.79 (s,
3H, OCH3), 3.00 (m, 4H, 7 & 9-H), 2.13 (m, 2H, 8-H). MS m/z 306 (M+ꢀ1). 4-((40-
methoxyphenyl)amino)-7,7-dimethyl-7,8,9,10-tetrahydro-2H-benzo[h]chromen-
2-one (33): 1H NMR (400 MHz, DMSO-d6): d 9.10 (br s, 1H, NH), 8.00 (d, 1H,
J = 8.4 Hz, Ar-H), 7.41 (d, 1H, J = 8.4 Hz, Ar-H), 7.25 (d, 2H, J = 8.4 Hz, Ar-H), 7.04
(d, 2H, J = 8.8 Hz, Ar-H), 5.04 (s, 1H, 3-H), 3.79 (s, 3H, OCH3), 2.76 (t, 2H,
J = 6.0 Hz, 10-H), 1.79 (m, 2H, 9-H), 1.65 (m, 2H, 8-H), 1.30 (s, 6H, (CH3)2). MS
m/z 348 (M+ꢀ1).
m/z
322
(M++1).
4-[(20-bromophenyl)amino]-7,8,9,10-tetrahydro-2H-
benzo[h]chromen-2-one (20): 1H NMR (400 MHz, DMSO-d6): d 9.21 (br s, 1H,
NH), 7.98–7.90 (m, 1H, Ar-H), 7.70–7.62 (m, 1H, Ar-H), 7.50–7.24 (m, 3H, Ar-H),
7.12 (d, 1H, J = 8.3 Hz, Ar-H), 5.35 (s, 1H, 3-H), 2.86–2.74 (m, 4H, 7 &10-H),
1.85–1.72 (m, 4H,
8
&
9-H). MS m/z 368 and 370 (1:1, M+ꢀ1). 4-[(30-
methylphenyl)amino]-7,8,9,10-tetrahydro-2H-benzo[h]chromen-2-one (21): 1H
NMR (400 MHz, DMSO-d6): d 9.15 (br s, 1H, NH), 7.95 (d, 1H, J = 8.3 Hz, Ar-