5-aryl-1,2,3,4-tetrahydrochromeno[3,4-f]quinolin-3-ones as a novel class of nonsteroidal progesterone receptor agonists: Effect of A-ring modification

Article abstract of DOI:10.1021/jm980723h

Optimization of the 1,2-dihydroquinoline A-ring of a nonsteroidal human progesterone receptor (hPR) agonist pharmacophore (1) was performed by using the cotransfection and receptor binding assays as guides. The 3-keto group was discovered to regain the potent agonist activity which was lost upon removal of the 3,4-olefin, and it led to a novel hPR agonist series, 5-aryl- 1,2,3,4-tetrahydrochromeno[3,4-f]quinolin-3-ones. The new progestins demonstrated potent hPR agonist activity in the cotransfection assay and high binding affinity similar to progesterone. T47D human breast cancer cell line was employed for further characterization of the new progestins and a number of reference analogues. It was found that the new 3-keto analogues showed full agonist activity in the T47D assay, while the reference compounds from other related nonsteroidal hPR agonist series exhibited only partial agonist activity.

Full text of DOI:10.1021/jm980723h

1466
J . Med. Chem. 1999, 42, 1466-1472
5-Ar yl-1,2,3,4-tetr a h yd r och r om en o[3,4-f]qu in olin -3-on es a s a Novel Cla ss of
Non ster oid a l P r ogester on e Recep tor Agon ists: Effect of A-Rin g Mod ifica tion
Lin Zhi,*,† Christopher M. Tegley,† Keith B. Marschke,‡ Dale E. Mais,§ and Todd K. J ones†,∇
Departments of Medicinal Chemistry, New Leads Discovery, and Endocrine Research, Ligand Pharmaceuticals, Inc.,
10275 Science Center Drive, San Diego, California 92121
Received December 23, 1998
Optimization of the 1,2-dihydroquinoline A-ring of a nonsteroidal human progesterone receptor
(hPR) agonist pharmacophore (1) was performed by using the cotransfection and receptor
binding assays as guides. The 3-keto group was discovered to regain the potent agonist activity
which was lost upon removal of the 3,4-olefin, and it led to a novel hPR agonist series, 5-aryl-
1,2,3,4-tetrahydrochromeno[3,4-f]quinolin-3-ones. The new progestins demonstrated potent hPR
agonist activity in the cotransfection assay and high binding affinity similar to progesterone.
T47D human breast cancer cell line was employed for further characterization of the new
progestins and a number of reference analogues. It was found that the new 3-keto analogues
showed full agonist activity in the T47D assay, while the reference compounds from other related
nonsteroidal hPR agonist series exhibited only partial agonist activity.
In tr od u ction
Several reports from our laboratory have described
the development of potent human progesterone receptor
(hPR) agonists based on a novel nonsteroidal pharma-
cophore, 5-substituted 1,2-dihydro-5H-chromeno[3,4-f]-
quinoline. Three separate series, 5-aryl (1),1 5-ben-
zylidene (2),2 and 5-alkyl (3)3 (Figure 1), have been
optimized by using the cell-based cotransfection assays4
to measure the modulated transcriptional activities of
hPR and the binding assay to detect the receptor/ligand
interaction. A number of analogues have demonstrated
potent hPR agonist activity in rodent models via oral
administration. Additionally, the 9-substituents were
shown to have a significant enhancement effect on the
agonist activity,5 and certain numbers of this class of
selective progesterone receptor modulators (4)6 display
encouraging and potentially useful tissue-selective ef-
fects. In addition to our hPR agonist series, the 1,2-
dihydro-2,2,4-trimethylquinoline motif contributed to
other nonsteroidal small molecules that interact with
hPR and hAR (human androgen receptor) as antago-
nists.7 In this paper we describe a new 3-quinolinone
hPR agonist series (5), which was discovered during the
A-ring optimization of the 5-aryl-1,2-dihydro-5H-
chromeno[3,4-f]quinoline pharmacophore for hPR ago-
nist activity.
F igu r e 1. Progesterone and 5-substituted dihydrochromeno-
[3,4-f]quinoline structures: 5-aryl compound 1, 5-benzylidene
compound 2, 5-alkyl compound 3, LG120746 (4), and the new
3-keto general structure 5.
Ch em istr y
palladium-catalyzed hydrogenation of the parent com-
pound 1. The 4-quinolinone analogue 10 was prepared
from ozonolysis of N-t-Boc-protected compound 7 in good
yield. Reduction of compound 10 followed by acid-
catalyzed elimination provided 4-desmethylquinoline
11.
The 3-quinolinones 5 (R ) aryl) were synthesized from
the corresponding 1,2-dihydroquinolines reported previ-
ously (1, 12-14) (Scheme 2). The general procedure
started from the protection of the quinoline nitrogen by
tert-butoxycarbonyl followed by a standard hydrobora-
The 4-methylidene compound 7 was isolated as a
byproduct from a previously described method1 of pre-
paring compound 1 from latone 6 (Scheme 1). Com-
pounds 8 and 9 were obtained in a 5:1 ratio from a
* Address correspondence to this author. Phone: (619) 550-7663.
Fax: (619) 550-7249. E-mail: lzhi@ligand.com.
† Department of Medicinal Chemistry.
‡ Department of New Leads Discovery.
§ Department of Endocrine Research.
∇ Current address: Ontogen Corp., 2325 Camino Vida Roble,
Carlsbad, CA 92009.
10.1021/jm980723h CCC: $18.00 © 1999 American Chemical Society
Published on Web 03/27/1999

A-Ring Modification of Nonsteroidal hPR Agonists
J ournal of Medicinal Chemistry, 1999, Vol. 42, No. 8 1467
Sch em e 1a
a
Reagents: (a) 4-ClPhLi, THF, -30 °C; (b) TFA, Et3SiH, CH2Cl2, rt; (c) H2, 10% Pd/C, EtOAc, rt; (d) n-BuLi, t-Boc2O, THF, -78 °C to
rt; (e) O3, MeOH, -78 °C; (f) TFA, CH2Cl2, rt; (g) DIBAL-H, toluene, rt; (h) TsOH, CH2Cl2, rt.
Sch em e 2a
a
Reagents: (a) n-BuLi, t-Boc2O, THF, -78 °C to rt; (b) BH3-THF, THF, rt; (c) H2O2, THF, rt; (d) PCC, CH2Cl2, rt; (e) TFA, CH2Cl2,
rt; (f) NaH, MeI, THF, rt.
tion procedure using borane-tetrahydrofuran complex
and hydrogen peroxide as reagents to afford a diaster-
eomeric mixture of two 3-hydroxy products (15 and 16).
Each of the isomers (15 or 16) was treated with
pyridinium chlorochromate (PCC) followed by TFA to
remove the protection group to give the corresponding
3-quinolinones 17-24 in moderate yield.8 A couple of
Scheme 3 describes the synthesis of 5-benzylidene
analogues with the modified A-ring. Compound 26 was
prepared by the addition of benzyl Grignard reagent to
the hydrogenated lactone 6 followed by an acid-
catalyzed elimination. The 3-quinolinones 28 and 29
were prepared by a different route from the 3-keto-5-
aryl analogue synthesis since the benzylidene moiety
was incompatible with the hydroboration procedure.
Lactone 6 was converted to intermediate 27 by the
standard hydroboration procedure, which included N-
Boc formation, hydroboration, and PCC oxidation. The
addition of 2 equiv of the benzylmagnesium bromide
gave the lactone adduct selectively without touching the
3-ketone. Treatment of the adduct with TFA provided
3-hydroxy intermediates (15b and 16b, R ) Cl, R1
)
R2 ) H) were prepared by hydrolysis of 15a and 16a
directly with TFA. Tetramethylquinolinone 25 was
prepared from 3-hydroxyquinoline 15a by oxidation with
PCC followed by methylation with iodomethane in the
presence of sodium hydride and then hydrolysis of the
Boc protection with TFA.

1468 J ournal of Medicinal Chemistry, 1999, Vol. 42, No. 8
Zhi et al.
Ta ble 1. Cotransfection and Competitive Binding Data for Reference Compounds and the New Analoguesa
hPR agonistb (mean ( SEM)
hPR antagonistb (mean ( SEM)
hPR-A binding
Ki (nM) (mean ( SEM)
compd
eff (%)
EC50 (nM)c
eff (%)
IC50 (nM)c
d
Prog
MPA
1
2
3
4
7
8
9
10
11
15b
16b
17
18
25
100 ( 0
80 ( 7
77 ( 5
132 ( 17
138 ( 12
117 ( 7
30 ( 5
39 ( 4
58 ( 18
-
2.9 ( 0.9
0.15 ( 0.05
14 ( 2
-
-
3.5 ( 0.2
0.34 ( 0.04
0.70 ( 0.14
0.83 ( 0.04
0.44 ( 0.03
0.32 ( 0.11
11.6 ( 2.1
10.1 ( 2.1
91 ( 11
-
-
31
600
7.6 ( 3.7
3.2 ( 0.9
2.8 ( 0.7
124 ( 54
39 ( 13
48 ( 28
-
-
-
-
-
-
-
81 ( 12
1755 ( 742
-
56
-
3100
376 ( 201
140
84 ( 4
24.6 ( 1.1
10.5 ( 1.2
>500
28
1300
50
69
91
-
-
-
-
3200
460
>500
102 ( 24
122 ( 26
36 ( 21
5.3 ( 2.1
4.5 ( 1.3
9.8 ( 6.9
-
-
21.3 ( 3.7
1.3 ( 0.1
5.3 ( 0.1
-
-
-
-
a
Values with standard errors (SEM) represent the mean value of at least three separate experiments with triplicate determinations;
b
values without standard deviations represent a single experiment. Agonist efficacies were compared to that of progesterone (100%), and
antagonist efficacies were determined as a function (%) of maximal inhibition of progesterone at the EC50 value. c All EC50 and IC50
values were determined from full dose-response curves ranging from 10-12 to 10-5 M in CV-1 cells. A dash indicates an efficacy of
d
<20% and a potency of >10 000 nM.
Sch em e 3a
7, saturation of the olefin provided a mixture of two
diastereomers 8 and 9, and removal of the 4-methyl
afforded compound 11. These changes made no improve-
ment of any kind over parent compound 1 in cotrans-
fection or binding assays (see Table 1). In comparison
of our nonsteroidal compounds with the typical steroidal
progestins, it was noticeable that the new structures
might lack a polar functional group to interact with the
steroidal receptor. To test this hypothesis, we introduced
a hydroxy or carbonyl group to the A-ring. The 3-quino-
linone analogues 17 and 18 exhibited significant potency
and efficacy improvement not only over the parent
compounds 8 and 9 but also over the corresponding
dihydroquinoline counterpart 1 in the cotransfection
assay. The added methyl group at C4 (25) diminished
the Ki and efficacy versus 18. The tetrahydro-4-quino-
linone 10 and 3-hydroxy analogues 15b and 16b showed
no activity as hPR agonists.
Four pairs of 5-aryl-3-quinolinone analogues were
synthesized, and their in vitro activities are listed in
Table 2. It was noticed that both stereoisomers showed
similar activity in the cotransfection assay but with
quite different binding affinity to hPR-A. The trans-
isomers (18, 20, 22, and 24) bind 5-10-fold better than
their cis-counterparts (17, 19, 21, and 23), which implies
that the trans-isomer should be more active than the
cis-isomer and the cell media might cause an epimer-
ization at C4 during the cotransfection assay process.
Two 5-benzylidene-3-quinolinone analogues (28 and 29)
were also prepared and evaluated in the assays. Com-
pound 28 exhibited improved potency over the 3-meth-
ylene analogue 26 but no difference with the corre-
sponding 1,2-dihydroquinoline analogue 2.
a
Reagents: (a) H2, 10% Pd/C, EtOAc, rt; (b) 3-FPhCH2MgBr,
ether, rt; (c) TsOH, CH2Cl2, rt; (d) n-BuLi, t-Boc2O, THF, -78 °C
to rt; (e) BH3-THF, THF, rt; (f) H2O2, THF/H2O, rt; (g) PCC,
CH2Cl2, rt; (h) RPhCH2MgBr, ether, rt; (i) TFA, CH2Cl2, rt.
the eliminated benzylidene moiety and at the same time
mediated the hydrolysis of the Boc protection to afford
28 and 29 in good yields.9
Biologica l Resu lts a n d Discu ssion
The structure-activity relationship (SAR) study of
the A-ring modification was guided by the cotransfection
assay to measure ligand-induced agonistic or antago-
nistic transcriptional responses of hPR in CV-1 cells
(African green monkey kidney fibroblasts) and by the
competitive binding assay of baculovirus-expressed
hPR-A to record the ligand binding affinity as previously
reported.1 Progesterone (Prog) and medroxyprogester-
one acetate (MPA) were used as progestin standards.
Our initial effort was to investigate the necessity of
the 3,4-olefin and 4-methyl group at the A-ring by
simply modifying compound 1. Shifting the 3,4-double
bond to an external olefin at C4 generated compound
The cross-reactivities of the new compounds were
monitored by the competitive binding assays of bacu-
lovirus-expressed human androgen receptor (hAR) and
glucocorticoid receptor (hGR). As observed with other
related nonsteroidal series, these new structures have
much less cross-reactivities than those of the steroidal
progestins (see Table 2).
In comparison of hPR agonist activity of the new
3-quinolinone analogues as a group with that of the 1,2-

A-Ring Modification of Nonsteroidal hPR Agonists
Ta ble 2. Cotransfection and Competitive Binding Data for the 3-Quinolinone Analoguesa
hPR agonistb (mean ( SEM)
binding Ki (nM) (mean ( SEM)
eff (%)
EC50 (nM)c
J ournal of Medicinal Chemistry, 1999, Vol. 42, No. 8 1469
compd
hPR-A
hAR
hGR
Prog
MPA
17
18
19
20
21
22
23
24
26
28
29
100 ( 0
80 ( 7
2.9 ( 0.9
0.15 ( 0.05
5.3 ( 2.1
4.5 ( 1.3
9.0 ( 3.5
10 ( 6
3.5 ( 0.2
0.34 ( 0.04
21.3 ( 3.7
1.3 ( 0.1
28.6 ( 3.3
6.6 ( 1.0
28 ( 6
2.6 ( 0.2
123 ( 19
16.6 ( 4.4
6.3 ( 0.1
3.5 ( 1.7
4.9 ( 1.3
8.5 ( 3.1
2.9 ( 0.2
698 ( 114
1177 ( 170
1075 ( 227
732 ( 18
504 (186
620 ( 112
807 ( 212
1091 ( 40
nad
30.5 ( 1.9
13.2 ( 1.8
913 ( 211
331 ( 31
909 ( 248
249 ( 157
864 ( 121
193 ( 55
250 ( 170
257 ( 96
na
102 ( 24
122 ( 26
103 ( 31
92 ( 10
114 ( 22
106 ( 10
66 ( 7
8.7 ( 1.5
6.3 ( 3.1
16 ( 5
93 ( 38
114 ( 49
155 ( 29
133 ( 38
14 ( 8
47 ( 13
8.7 ( 5.5
17 ( 6
560 ( 196
1196 ( 76
4728 ( 4272
680 ( 270
a
Values with standard errors (SEM) represent the mean value of at least three separate experiments with triplicate determinations.
Agonist efficacies were compared to that of progesterone (100%). c All EC50 values were determined from full dose-response curves
b
ranging from 10-12 to 10-5 M in CV-1 cells. na indicates the data is not available.
d
Ta ble 3. T47D and CV-1 Cell Line Data for Reference
Compounds and the New Analoguesa
hPR agonistb (mean ( SEM)
T47D cells
CV-1 cells
compd
eff (%)
EC50 (nM)c
eff (%)
EC50 (nM)c
Prog
MPA
1
2
3
100 ( 0
90 ( 15
48 ( 6
55 ( 8
42 ( 14
47 ( 9
107 ( 25
97 ( 21
102
92 ( 2
107 ( 3
96 ( 7
103
1.8 ( 0.3
0.33 ( 0.05
32 ( 2
100 ( 0
80 ( 7
2.9 ( 0.9
0.15 ( 0.05
14 ( 2
7.6 ( 3.7
3.2 ( 0.9
2.8 ( 0.7
5.3 ( 2.1
4.5 ( 1.3
9.0 ( 3.5
10 ( 6
8.7 ( 1.5
6.3 ( 3.1
16 ( 5
14 ( 8
8.7 ( 5.5
17 ( 6
77 ( 5
51 ( 15
10 ( 7
132 ( 17
138 ( 12
117 ( 7
102 ( 24
122 ( 26
103 ( 31
92 ( 10
114 ( 22
106 ( 10
66 ( 7
4
27 ( 5
17
18
19
20
21
22
23
24
28
29
22.6 ( 2.5
10.9 ( 2.7
35
23.5 ( 7.7
26.0 ( 5.6
14.8 ( 10
63
F igu r e 2. Concentration-response curves for progesterone
and the representative compounds from each different non-
steroidal hPR agonist series in the T47D alkaline phosphatase
assay.
85
83 ( 3
93 ( 13
37
93 ( 38
155 ( 29
133 ( 38
25.3 ( 7.3
18.3 ( 6.6
a
Values with standard errors (SEM) represent the mean value
of at least three separate experiments with triplicate determina-
characterize synthetic progestins or antiprogestins.10
The new 3-quinolinones and a number of reference
analogues from other related series as well as steroidal
progestins were tested in this assay. Table 3 lists the
EC50 values from the T47D cells and the CV-1 cells for
comparison. Progesterone and MPA demonstrated simi-
lar agonist activity in both cell lines, while compounds
1-4, which represent three different 1,2-dihydroquino-
line series, showed much weaker agonist activity in the
T47D cell line although they are full agonists in the
CV-1 cell line. Interestingly, all the new 3-quinolinone
analogues gave full agonist activities in both assays.
Figure 2 illustrated the differences among these non-
steroidal series and progesterone in the T47D alkaline
phosphatase assay. It seems that the 3-keto compounds
are closer to steroids in terms of the agonist activity.
The in vivo relevance of the difference in T47D cells is
to be determined.
tions; values without standard deviations represent
a single
b
experiment. Agonist efficacies were compared to that of proges-
terone (100%). c All EC50 values were determined from full dose-
response curves ranging from 10-12 to 10-5 M in CV-1 cells.
dihydroquinoline series 1,1 it is evident that the sub-
stituents on the 5-aryl have less impact on the agonist
activity in the new series than in the 1,2-dihydroquino-
line series. For example, compounds 18 (5-p-chloro-
phenyl) and 20 (5-phenyl) have similar agonist activity,
while compound 1 (5-p-chlorophenyl) is 10-fold more
potent than its parent 5-phenyl analogue (see ref 1 for
the bioassay data).
In a previous effort to understand how our nonste-
roidal compounds mimic steroids, we suggested that the
quinoline ring of compound 1 might overlap with the
steroid D-ring based on a CoMFA study.1 The charge
distribution, dipole moment, and direction of the new
3-quinolinone analogues are dramatically different from
the compound 1 series, and they do not fit the previous
model. To evaluate the possible biological consequence
caused by the differences of the new compounds, we
employed the T47D cell line as secondary assay to
further characterize their in vitro activity.
Con clu sion
A novel 3-quinolinone hPR agonist series was devel-
oped and examined in the cotransfection and competi-
tive binding assays. The new compounds demonstrated
improved activity over their parent quinoline analogues
in the 5-aryl series. The 3-keto group is the key to
regaining the hPR agonist activity that was lost upon
T47D human breast cancer cells express high levels
of hPR, and they are one of the major models to

1470 J ournal of Medicinal Chemistry, 1999, Vol. 42, No. 8
Zhi et al.
mL) in CH2Cl2. Standard workup followed by chromatography
afforded compound 10 as a yellow oil (35 mg, 47%): 1H NMR
(acetone-d6) 7.86 (d, J ) 8.8, 1 H), 7.60 (dd, J ) 7.8, 1.5, 1 H),
7.40 (s, 1 H), 7.20 (s, 4 H), 7.06 (td, J ) 7.8, 1.5, 1 H), 6.98 (d,
J ) 8.8, 1 H), 6.90 (td, J ) 7.8, 1.5, 1 H), 6.83 (dd, J ) 7.8, 1.5,
1 H), 6.38 (s, 1 H), 2.64 (d, J ) 15.2, 1 H), 2.43 (d, J ) 15.2, 1
H), 1.37 (s, 3 H), 1.27 (s, 3 H). Anal. (C24H20ClNO2) C, H, N.
removal of the 3,4-olefin in the 1,2-dihydroquinoline
series. The assay results from the T47D human breast
cancer cell line revealed that the new series behaved
similarly to steroidal progestins but differently than
other related nonsteroidal 1,2-dihydroquinoline series.
Due to the lengthy synthesis and two stereogenic
centers of the 3-quinolinones, these new structures pose
obvious chemical disadvantages over other related
series.
(R,S)-5-(4-Ch lor op h en yl)-1,2-d ih yd r o-2,2-d im eth yl-5H-
ch r om en o[3,4-f]qu in olin e (11). To a solution of compound
10 (20 mg, 0.050 mmol) in toluene (2 mL) at -78 °C was added
DIBAL-H (0.2 mL, 0.5 M in toluene, 0.10 mmol), and the
resulting mixture was warmed to room temperature. The
reaction was quenched with water, extracted with EtOAc, and
concentrated, and chromatography afforded the 4-hydroxy
intermediate as a colorless oil. The intermediate was treated
with a catalytic amount of TsOH in CH2Cl2 (2 mL) at room
temperature for 3 h and quenched with Na2CO3. Extraction
with EtOAc and removal of solvent followed by chromatogra-
phy afforded compound 11 as a colorless oil (10 mg, 54%): 1H
NMR (acetone-d6) 7.60 (d, J ) 7.9, 1 H), 7.52 (d, J ) 8.5, 1 H),
7.27 (d, J ) 8.6, 2 H), 7.24 (d, J ) 8.6, 2 H), 7.01 (t, J ) 7.9,
1 H), 6.88 (t, J ) 7.9, 1 H), 6.81 (d, J ) 7.9, 1 H), 6.69 (d, J )
8.5, 1 H), 6.57 (s, 1 H), 6.36 (d, J ) 7.5, 1 H), 5.59 (d, J ) 7.5,
Exp er im en ta l Section
General experimental methods have been previously de-
scribed,1 and reported yields are not optimized. All the chiral
1
compounds were tested as racemic. H and 13C NMR spectra
were obtained on a Bruker AC400 spectrometer at 400 and
100 MHz, respectively, and are reported in δ (ppm) units; J
values are given in hertz (Hz).
(R,S)-5-(4-Ch lor oph en yl)-1,2,3,4-tetr ah ydr o-2,2-dim eth -
yl-4-m eth ylen e-5H-ch r om en o[3,4-f]qu in olin e (7). This com-
pound was prepared from 4-bromochlorobenzene (1.4 g, 7
mmol) and lactone 6 (0.50 g, 1.7 mmol) by a previously
described procedure1 as a byproduct (53 mg, 8%) as a white
solid: 1H NMR (CDCl3) 7.53 (d, J ) 7.7, 1 H), 7.51 (d, J ) 8.3,
1 H), 7.18 (d, J ) 8.7, 2 H), 7.15 (d, J ) 8.7, 2 H), 6.99 (t, J )
7.7, 1 H), 6.90 (t, J ) 7.7, 1 H), 6.79 (d, J ) 7.7, 1 H), 6.59 (s,
1 H), 6.58 (d, J ) 8.3, 1 H), 4.93 (s, 1 H), 4.59 (s, 1 H), 4.09 (br
s, 1 H), 2.43 (d, J ) 12.3, 1 H), 2.18 (d, J ) 12.3, 1 H), 1.34 (s,
3 H), 1.13 (s, 3 H); 13C NMR (CDCl3) 151.2, 144.3, 138.7, 137.7,
133.9, 130.4, 130.3, 128.7, 127.6, 124.9, 124.6, 122.2, 121.9,
119.4, 118.0, 117.3, 114.9, 114.4, 74.6, 50.9, 46.0, 30.9, 28.8,
27.7; IR (KBr) 3393, 2955, 1595, 1487, 1442, 1332, 1207, 756.
Anal. (C25H22ClNO‚1/4H2O) C, H, N.
1 H), 5.55 (s, 1 H), 1.32 (s, 3 H), 1.30 (s, 3 H). Anal. (C24H20
ClNO) C, H, N.
-
(R,S)-(4l,5u )-5-(4-Ch lor oph en yl)-1,2,3,4-tetr ah ydr o-2,2,4-
t r im et h yl-5H -ch r om en o[3,4-f]q u in olin -3-on e (17) a n d
(R,S)-(4l,5l)-5-(4-Ch lor op h en yl)-1,2,3,4-tetr a h yd r o-2,2,4-
tr im eth yl-5H-ch r om en o[3,4-f]qu in olin -3-on e (18). The title
compounds were prepared by a four-step procedure from
compound 1, which includes the protection of the free NH with
t-Boc group, hydroboration followed by oxidation with H2O2
and PCC, and hydrolysis of the t-Boc protection.
To a yellow solution of compound 1 (120 mg, 0.31 mmol) in
THF (6 mL) at -78 °C was added n-BuLi (0.30 mL, 1.6 M in
hexane, 0.48 mmol), the resulting solution was stirred for 15
min, and then a solution of di-tert-butyl dicarbonate (0.15 g,
0.69 mmol) in THF (2 mL) was introduced. The reaction
mixture was allowed to warm to room temperature and was
stirred for 5 h. The reaction was quenched with water and
extracted with EtOAc (2 × 20 mL). Removal of solvent followed
by chromatography (EtOAc-hexane, 10-30% gradient) af-
forded the t-Boc-protected compound 1 (0.10 g, 68%).
The t-Boc-protected intermediate (0.10 g, 0.21 mmol) in THF
(4 mL) was treated with BH3-THF (0.30 mL, 1.0 M in THF,
0.30 mmol) at room temperature for 3 h and was quenched
with KOH (0.20 mL, 3 M aqueous). To the above solution was
added H2O2 (0.20 mL, 30% in water), and the mixture was
stirred for 30 min. The mixture was diluted with water and
extracted, washed with brine, and concentrated. Chromatog-
raphy of the crude mixture (EtOAc-hexane, 10-30% gradient)
afforded compound 15a (51 mg, 50%) and compound 16a (26
mg, 25%) as colorless oils.
Compound 15a (40 mg, 0.079 mmol) was oxidized with PCC
(0.10 g, 0.46 mmol) in CH2Cl2 (5 mL) at room temperature for
60 min to yield the ketone as a colorless oil after chromatog-
raphy. The colorless oil was then treated with TFA (0.4 mL)
in CH2Cl2 (1 mL) for 30 min and was quenched with KOH (5
mL, 2% aqueous). The reaction mixture was extracted with
EtOAc, washed with brine, and concentrated. Chromatography
of the crude residue (EtOAc-hexane, 10-30% gradient) af-
forded compound 17 (25 mg, 78%) as a white solid: 1H NMR
(CDCl3) 7.64 (d, J ) 8.2, 2 H), 7.18 (d, J ) 8.6, 2 H), 7.13 (d,
J ) 8.6, 2 H), 7.05 (t, J ) 7.9, 1 H), 6.96 (t, J ) 7.8, 1 H), 6.84
(d, J ) 8.3, 1 H), 6.76 (d, J ) 7.9, 1 H), 6.37 (s, 1 H), 3.73 (s,
1 H), 3.56 (q, J ) 7.4, 1 H), 1.44 (s, 3 H), 1.26 (s, 3 H), 0.87 (d,
J ) 7.4, 3 H); 13C NMR (CDCl3) 214.1, 150.7, 143.2, 137.8,
134.7, 130.5, 130.3, 128.9, 128.6, 123.4, 122.7, 122.4, 122.2,
118.3, 116.8, 74.4, 60.2, 43.8, 28.1, 27.3, 16.6; IR (neat) 3400,
2950, 1740, 1490, 1330, 1230. Anal. (C25H22ClNO2) C, H, N.
(R,S)-(4l,5l)-5-(4-Ch lor oph en yl)-1,2,3,4-tetr ah ydr o-2,2,4-
tr im eth yl-5H-ch r om en o[3,4-f]qu in olin e (8) a n d (R,S)-
(4l,5u )-5-(4-Ch lor op h en yl)-1,2,3,4-t et r a h yd r o-2,2,4-t r i-
m eth yl-5H-ch r om en o[3,4-f]qu in olin e (9). To a solution of
compound 1 (0.10 g, 0.25 mmol) in EtOAc (10 mL) was added
10% Pd/C (20 mg, 0.019 mmol), and the mixture was exposed
to a hydrogen balloon overnight. Filtration from the catalyst
and removal of solvent afforded compound 8 (80 mg, 80%) as
1
a white solid: mp 158-159 °C; H NMR (acetone-d6) 7.63 (d,
J ) 7.8, 1 H), 7.53 (d, J ) 8.5, 1 H), 7.24 (s, 4 H), 6.94 (t, J )
7.8, 1 H), 6.87 (t, J ) 7.8, 1 H), 6.76 (d, J ) 8.5, 1 H), 6.68 (d,
J ) 7.8, 1 H), 6.51 (s, H), 5.10 (br s, 1 H), 3.25 (m, 1 H), 1.89
(dd, J ) 13.5, 6.4, 1 H), 1.76 (dd, J ) 13.5, 4.4, 1 H), 1.30 (s,
3 H), 1.21 (s, 3 H), 0.83 (d, J ) 7.3, 3 H); 13C NMR (CDCl3)
150.6, 144.5, 138.6, 134.0, 130.9, 130.5, 128.4, 127.6, 124.9,
123.2, 122.2, 121.9, 120.2, 118.0, 115.8, 74.5, 50.0, 44.3, 31.6,
31.3, 27.5, 22.8. Anal. (C25H24ClNO) C, H, N.
Compound 9 was also isolated as a white solid (15 mg,
15%): 1H NMR (CDCl3) 7.54 (d, J ) 7.6, 1 H), 7.47 (d, J ) 8.4,
1 H), 7.15 (d, J ) 6.5, 2 H), 7.10 (d, J ) 6.5, 2 H), 7.01 (t, J )
7.6, 1 H), 6.89 (t, J ) 7.6, 1 H), 6.83 (d, J ) 7.6, 1 H), 6.59 (d,
J ) 8.4, 1 H), 6.47 (s, 1 H), 3.73 (br s, 1 H), 2.82 (m, 1 H), 1.76
(dd, J ) 13.5, 7.0, 1 H), 1.73 (dd, J ) 13.5, 4.5, 1 H), 1.46 (d,
J ) 7.1, 3 H), 1.36 (s, 3 H), 1.19 (s, 3 H); 13C NMR (CDCl3)
150.5, 143.9, 138.4, 134.0, 130.3, 129.4, 128.6, 127.6, 124.2,
122.6, 122.1, 119.6, 118.0, 115.4, 74.4, 50.1, 42.9, 32.2, 31.8,
27.3, 22.3. Anal. (C25H24ClNO) C, H, N.
(R,S)-5-(4-Ch lor oph en yl)-1,2,3,4-tetr ah ydr o-2,2-dim eth -
yl-5H-ch r om en o[3,4-f]qu in olin -4-on e (10). To a solution of
compound 7 (0.10 g, 0.26 mmol) in THF (6 mL) at -78 °C were
added n-BuLi (0.25 mL, 1.6 M in hexane, 0.40 mmol) and a
solution of t-Boc2O (0.10 g, 0.44 mmol) in THF (3 mL). The
reaction mixture was warmed slowly to room temperature and
quenched with water. Extraction with EtOAc and removal of
solvent followed by chromatography afforded N-t-Boc-protected
compound 7 as an oil (75 mg, 59%).
A solution of the N-t-Boc-protected compound 7 in methanol
(20 mL) at - 78 °C was subjected to O3 for 3 min, and SMe2
(0.5 mL) was added. The reaction mixture was warmed to room
temperature and concentrated. Chromatography provided the
product as a colorless oil, which was treated with TFA (0.5
Compound 16a (20 mg, 0.040 mmol) was oxidized with PCC
for 6 h and then deprotected by a similar method as described
above to yield compound 18 (13 mg, 84%) as a white solid: 1H
NMR (CDCl3) 7.59 (d, J ) 8.4, 1 H), 7.57 (d, J ) 8.0, 1 H),

A-Ring Modification of Nonsteroidal hPR Agonists
J ournal of Medicinal Chemistry, 1999, Vol. 42, No. 8 1471
7.15 (d, J ) 8.5, 2 H), 7.06 (d, J ) 8.5, 2 H), 7.04 (m, 1 H),
6.94 (t, J ) 7.8, 1 H), 6.85 (d, J ) 7.6, 1 H), 6.83 (d, J ) 8.3,
1 H), 3.73 (s, 1 H), 3.35 (d, J ) 7.5, 1 H), 1.50 (d, J ) 7.5, 3 H),
1.46 (s, 3 H), 1.17 (s, 3 H); 13C NMR (CDCl3) 213.1, 150.8,
142.7, 137.5, 134.4, 130.3, 130.0, 129.3, 128.9, 128.8, 128.6,
123.6, 122.8, 122.5, 122.4, 118.3, 116.8, 74.2, 60.1, 43.0, 31.2,
27.3, 26.6, 18.3. Anal. (C25H22ClNO2) C, H, N.
(R,S)-(3l,4u ,5l)-4-(Ch lor op h en yl)-1,2,3,4-tetr a h yd r o-3-
h yd r oxy-2,2,4-t r im et h yl-5H -ch r om en o[3,4-f]q u in olin e
(15b). Compound 15a (10 mg, 0.020 mmol) was treated with
TFA (0.2 mL) in CH2Cl2 (0.5 mL) for 1 h, and standard workup
procedure provided the title compound as a colorless oil (8.0
mg, 97%): 1H NMR (CDCl3) 7.55 (d, J ) 7.8, 1 H), 7.50 (d, J
) 8.3, 1 H), 7.15 (d, J ) 8.8, 2 H), 7.12(d, J ) 8.8, 2 H), 6.99
(t, J ) 7.8, 1 H), 6.91 (t, J ) 7.8, 1 H), 6.75 (d, J ) 7.9, 1 H),
6.70 (d, J ) 8.3, 1 H), 6.32 (s, H), 3.74 (s, 1 H), 3.48 (m, 1 H),
2.99 (m, 1 H), 1.91 (d, J ) 6.5, 1 H), 1.28 (s, 3 H), 1.18 (s, 3 H),
0.92 (d, J ) 7.3, 3 H). Anal. (C25H24ClNO2) C, H, N.
(R,S)-(3l,4u ,5u )-4-(Ch lor op h en yl)-1,2,3,4-tetr a h yd r o-3-
h yd r oxy-2,2,4-t r im et h yl-5H -ch r om en o[3,4-f]q u in olin e
(16b). Compound 16a (18 mg, 0.012 mmol) was converted to
compound 16b as a colorless oil (12 mg, 84%) in a similar
fashion: 1H NMR (CDCl3) 7.55 (d, J ) 7.8, 1 H), 7.51 (d, J )
8.4, 1 H), 7.13 (d, J ) 8.6, 2 H), 7.05 (d, J ) 8.6, 2 H), 7.03 (m,
1 H), 6.90 (t, J ) 7.6, 1 H), 6.85 (d, J ) 8.0, 1 H), 6.65 (d, J )
8.3, 1 H), 6.51 (s, 1 H), 3.74 (s, 1 H), 3.53 (dd, J ) 7.3, 4.6, 1
H), 2.65 (qd, J ) 7.8, 4.5, 1 H), 1.70 (d, J ) 7.3, 1 H), 1.56 (d,
J ) 7.8, 3 H), 1.32 (s, 3 H), 1.13 (s, 3 H). Anal. (C25H24ClNO2)
C, H, N.
(R,S)-(4l,5u )-1,2,3,4-Tetr a h yd r o-2,2,4-tr im eth yl-5-p h en -
yl-5H-ch r om en o[3,4-f]qu in olin -3-on e (19) an d (R,S)-(4l,5l)-
1,2,3,4-Tetr ah ydr o-2,2,4-tr im eth yl-5-ph en yl-5H-ch r om en o-
[3,4-f]qu in olin -3-on e (20). The title compounds were prepared
from compound 12 (0.10 g, 0.28 mmol) by the same method as
described in the synthesis of 17 and 18. Compound 19 was
obtained in an 18% four-step yield (19 mg) as a white powder:
mp 108-110 °C; 1H NMR (CDCl3) 7.66 (d, J ) 7.7, 1 H), 7.64
(d, J ) 8.2, 1 H), 7.20 (s, 5 H), 7.06 (t, J ) 7.7, 1 H), 6.95 (t, J
) 7.7, 1 H), 6.83 (d, J ) 8.2, 1 H), 6.77 (d, J ) 7.7, 1 H), 6.39
(s, 1 H), 3.72 (bs, 1 H), 3.58 (q, J ) 7.4, 1 H), 1.44 (s, 3 H),
1.23 (s, 3 H), 0.80 (d, J ) 7.4, 3 H); 13C NMR (CDCl3) 214.4,
151.0, 143.2, 139.3, 131.1, 128.9, 128.8, 128.6, 128.5, 123.4,
122.7, 122.2, 122.1, 122.0, 118.3, 116.6, 75.4, 60.2, 43.9, 28.1,
27.3, 16.3. Anal. (C25H23NO2‚3/4H2O) C, H, N.
122.8, 122.7, 122.4, 122.2, 118.3, 116.8, 115.5 (d, J ) 21.6),
114.9 (d, J ) 22.6), 74.2, 60.1, 43.0, 27.3, 26.6, 18.4. Anal.
(C25H22FNO2) C, H, N.
(R,S)-(4l,5u )-1,2,3,4-Tetr a h yd r o-2,2,4-tr im eth yl-5-(3-tr i-
flu or om e t h ylp h e n yl)-5H -ch r om e n o[3,4-f]q u in olin -3-
on e (23) a n d (R,S)-(4l,5l)-1,2,3,4-Tet r a h yd r o-2,2,4-t r i-
m et h yl-5-(3-t r iflu or om et h ylp h en yl)-5H -ch r om en o[3,4-
f]qu in olin -3-on e (24). The title compounds were prepared
from compound 14 (0.10 g, 0.24 mmol) by the same method as
described in the synthesis of 17 and 18. Compound 23 was
obtained in a 19% four-step yield (20 mg) as a colorless oil:
1H NMR (CDCl3) 7.67 (d, J ) 8.3, 1 H), 7.65 (d, J ) 7.7, 1 H),
7.52 (s, 1 H), 7.48 (m, 1 H), 7.35-7.30 (m, 2 H), 7.08 (t, J )
7.7, 1 H), 6.98 (t, J ) 7.7, 1 H), 6.88 (d, J ) 8.3, 1 H), 6.78 (d,
J ) 7.7, 1 H), 6.43 (s, 1 H), 3.75 (s, 1 H), 3.57 (q, J ) 7.4, 1 H),
1.45 (s, 3 H), 1.24 (s, 3 H), 0.86 (d, J ) 7.4, 3 H); 13C NMR
(CDCl3) 214.0, 150.5, 143.3, 140.3, 132.1, 131.2 (q, J ) 31.7),
130.0, 129.1, 128.7, 125.7, 123.3, 122.7, 122.6, 122.5, 122.2,
118.3, 117.1, 74.3, 60.2, 43.8, 28.2, 27.3, 16.5. Anal. (C26H22F3-
NO2‚1/2H2O) C, H, N.
Compound 24 was obtained in a 15% four-step yield (15 mg)
as a colorless oil: 1H NMR (CDCl3) 7.61 (d, J ) 8.3, 1 H), 7.57
(d, J ) 7.7, 1 H), 7.42 (t, J ) 7.7, 1 H), 7.39 (s, 1 H), 7.38-7.30
(m, 2 H), 7.09 (t, J ) 7.7, 1 H), 6.95 (d, J ) 7.7, 1 H), 6.91 (d,
J ) 8.4, 1 H), 6.86 (d, J ) 8.3, 1 H), 6.39 (s, 1 H), 3.77 (s, 1 H),
3.37 (q, J ) 7.3, 1 H), 1.50 (d, J ) 7.3, 3 H), 1.48 (s, 3 H), 1.20
(s, 3 H); 13C NMR (CDCl3) 213.1, 150.7, 142.8, 131.1, 129.4,
129.1, 128.6, 125.4, 124.6, 123.0, 122.7, 122.6, 122.5, 122.2,
118.3, 117.0, 74.0, 60.2, 43.1, 27.1, 26.5, 18.4. Anal. (C26H22F3-
NO2‚1/4H2O) C, H, N.
(R,S)-5-(4-Ch lor op h en yl)-1,2,3,4-tetr a h yd r o-2,2,4,4-tet-
r a m eth yl-5H-ch r om en o[3,4-f]qu in olin -3-on e (25). To a
solution of 1-tert-butoxycarbonyl compound 17 (25 mg, 0.050
mmol) in THF (3 mL) were added NaH (10 mg, 60% in mineral
oil, 0.25 mmol) and MeI (0.10 mL, 1.6 mmol); the resulting
slurry was stirred at room temperature for 2 h and was
quenched with water (5 mL). The mixture was extracted with
EtOAc and concentrated to give the crude product, which was
treated with TFA (0.5 mL) in CH2Cl2 (1 mL) at room temper-
ature for 1 h. The mixture was quenched with NaOH (3 mL,
2 M aqueous), extracted, and concentrated, and chromatog-
raphy provided compound 25 (10 mg, 48%) as a colorless oil:
1H NMR (CDCl3) 7.59 (d, J ) 8.2, 1 H), 7.56 (d, J ) 7.8, 1 H),
7.13 (d, J ) 8.7, 2 H), 7.09 (d, J ) 8.7, 2 H), 7.01 (t, J ) 7.9,
1 H), 6.91 (t, J ) 7.9, 1 H), 6.85 (s, 1 H), 6.83-6.78 (m, 2 H),
3.83 (s, 1 H), 1.63 (s, 3 H), 1.38 (s, 3 H), 1.33 (s, 3 H), 1.28 (s,
3 H). Anal. (C26H24ClNO2) C, H, N.
(Z)-5-(3-F lu or ob en zylid en e)-1,2,3,4-t et r a h yd r o-2,2,4-
tr im eth yl-5H-ch r om en o[3,4-f]qu in olin e (26). A solution of
lactone 6 (20 mg, 0.07 mmol) in EtOAc (10 mL) was hydroge-
nated with a hydrogen balloon in the presence of 10% Pd/C (5
mg) at room temperature overnight until the reaction went to
completion by TLC. The reaction mixture was filtered and
concentrated in vacuo to afford 1,2,3,4-tetrahydro-2,2,4-tri-
methyl-5-coumarino[3,4-f]quinoline (14 mg, 70%) as a yellow
solid.
Compound 20 was obtained in a 10% four-step yield as a
white powder (10 mg): 1H NMR (CDCl3) 7.59 (d, J ) 8.3, 1
H), 7.57 (d, J ) 7.6, 1 H), 7.21-7.12 (m, 5 H), 7.05 (t, J ) 7.6,
1 H), 6.92 (t, J ) 7.6, 1 H), 6.86 (d, J ) 7.6, 1 H), 6.83 (d, J )
8.3, 1 H), 6.37 (s, 1 H), 3.72 (bs, 1 H), 3.41 (q, J ) 7.5, 1 H),
1.50 (d, J ) 7.5, 3 H), 1.45 (s, 3 H), 1.17 (s, 3 H). Anal. (C25H23
NO2) C, H, N
-
(R,S)-(4l,5u )-1,2,3,4-Tet r a h yd r o-2,2,4-t r im et h yl-5-(3-
flu or oph en yl)-5H-ch r om en o[3,4-f]qu in olin -3-on e (21) an d
(R,S)-(4l,5l)-1,2,3,4-Tetr a h yd r o-2,2,4-tr im eth yl-5-(3-flu o-
r op h en yl)-5H-ch r om en o[3,4-f]qu in olin -3-on e (22). The
title compounds were prepared from compound 13 (80 mg, 0.21
mmol) by the same method as described in the synthesis of
17 and 18. Compound 21 was obtained in a 22% four-step yield
(18 mg) as a colorless oil: 1H NMR (CDCl3) 7.66 (d, J ) 7.7, 1
H), 7.64 (d, J ) 8.3, 1 H), 7.19 (td, J ) 7.9, 5.8, 1 H), 7.09-
6.86 (m, 5 H), 6.85 (d, J ) 8.3, 1 H), 6.78 (d, J ) 7.7, 1 H),
6.38 (s, 1 H), 3.72 (bs, 1 H), 3.58 (q, J ) 7.4, 1 H), 1.44 (s, 3
H), 1.23 (s, 3 H), 0.87 (d, J ) 7.4, 3 H); 13C NMR (CDCl3) 214.1,
162.9 (d, J ) 246.2), 150.7, 143.3, 141.8 (d, J ) 6.3), 130.4,
130.2, 130.1, 128.6, 124.6, 123.3, 122.7, 122.4, 122.3 (d, J )
22.1), 118.3, 116.9, 115.8 (d, J ) 21.4), 74.5, 60.2, 43.9, 28.1,
27.3, 14.4. Anal. (C25H22FNO2) C, H, N.
Compound 22 was obtained in a 16% four-step yield (13 mg)
as a colorless oil: 1H NMR (CDCl3) 7.60 (d, J ) 8.3, 1 H), 7.58
(d, J ) 7.7, 1 H), 7.15 (td, J ) 7.9, 5.8, 1 H), 7.09 (t, J ) 7.7,
1 H), 6.97-80 (m, 6 H), 6.34 (s, 1 H), 3.73 (s, 1 H), 3.38 (q, J
) 7.3, 1 H), 1.50 (d, J ) 7.3, 3 H), 1.46 (s, 3 H), 1.19 (s, 3 H);
13C NMR (100 MHz, CDCl3) 213.2, 162.9 (d, J ) 246.7), 150.8,
142.7, 141.6 (d, J ) 6.4), 130.2, 130.1, 129.9, 128.5, 123.6,
Addition of freshly prepared 3-fluorobenzylmagnesium bro-
mide (0.10 mL, 1.0 M in ether, 0.10 mmol) to the above
tetrahydroquinoline (14 mg, 0.05 mmol) and then treatment
with an acid according to the previously described General
Procedure for Preparing 5-Benezylidene Compounds2 afforded
compound 26 as a yellow solid (8.6 mg, 46%): Rf ) 0.38 (silica
gel, 25% EtOAc:Hex); 1H NMR (acetone-d6) 7.82 (d, J ) 8.5, 1
H), 6.69 (m, 1 H), 7.62 (d, J ) 8.5, 1 H), 7.58 (d, J ) 8.5, 1 H),
7.40 (m, 1 H), 7.22 (m, 2 H), 7.08 (m, 1 H), 6.97 (m, 1 H), 6.74
(d, J ) 8.5, 1 H), 6.24 (s, 1 H), 5.30 (brs, 1 H), 3.76 (m, 1 H).
1.97 (m, 1 H), 1.55 (m, 1 H), 1.40 (d, J ) 6.6, 3 H), 1.30 (s, 3
H), 1.26 (s, 3 H). Anal. (C26H24FNO) C, H, N.
(R,S)-(Z)-5-(3-F lu or ob en zylid en e)-1,2,3,4-t et r a h yd r o-
2,2,4-t r im et h yl-5H -ch r om en o[3,4-f]q u in olin -3-on e (28).
To a yellow solution of compound 6 (0.22 g, 0.76 mmol) in THF
(10 mL) at -78 °C was added n-BuLi (0.5 mL, 1.6 M in hexane,
0.80 mmol) to give a dark red solution. A solution of t-Boc2O
(0.25 g, 1.1 mmol) in THF (5 mL) was cannulated to the

1472 J ournal of Medicinal Chemistry, 1999, Vol. 42, No. 8
Zhi et al.
reaction mixture, and the reaction was warmed slowly to room
temperature and quenched with water. Extraction with EtOAc
and removal of solvent followed by chromatography afforded
1-tert-butoxycarbonyl lactone 6 as a yellow oil (0.22 g, 74%):
1H NMR (CDCl3) 7.97 (dd, J ) 8.0, 1.0, 1 H), 7.91 (d, J ) 9.0,
1 H), 7.73 (d, J ) 9.0, 1 H), 7.44 (td, J ) 8.1, 1.2, 1 H), 7.32 (d,
J ) 8.0, 1 H), 7.30 (t, J ) 8.1, 1 H), 5.77 (d, J ) 1.1, 1 H), 2.13
(d, J ) 1.1, 3 H), 1.55 (s, 9 H), 1.49 (s, 6 H).
The N-t-Boc-protected lactone 6 (0.22 g, 0.56 mmol) was
converted to compound 27 by a hydroboration-oxidation
procedure described in the synthesis of 17 and 18 in 22% yield
(50 mg) as a yellow oil: 1H NMR (CDCl3) 8.03 (d, J ) 8.9, 1
H), 8.00 (d, J ) 8.1, 1 H), 7.67 (d, J ) 8.9, 1 H), 7.48 (t, J )
8.1, 1 H), 7.35 (d, J ) 8.1, 1 H), 7.33 (t, J ) 8.1, 1 H), 5.25 (q,
J ) 7.3, 1 H), 1.87 (s, 3 H), 1.66 (d, J ) 7.3, 3 H), 1.52 (s, 9 H),
1.36 (s, 3 H).
To a solution of compound 27 (15 mg, 0.037 mmol) in THF
(1 mL) at -78 °C was added the freshly prepared 3-fluoroben-
zylmagnesium bromide (0.10 mL, 1.0 M in ether, 0.10 mmol),
and the reaction was slowly warmed to room temperature and
was quenched with water (1 mL). The mixture was extracted
with EtOAc (2 × 5 mL) and was concentrated to provide the
crude intermediate, which was treated with excess TFA (0.2
mL) in CH2Cl2 (1 mL) for 30 min and then quenched with 5%
NaOH (5 mL). The mixture was extracted with EtOAc and
concentrated, and chromatography afforded compound 28 in
a 60% two-step yield as a yellowish oil (8.8 mg): 1H NMR
(CDCl3) 7.73 (d, J ) 7.8, 1 H), 7.70 (d, J ) 11.1, 1 H), 7.60 (d,
J ) 8.3, 1 H), 7.42 (d, J ) 7.8, 1 H), 7.31 (td, J ) 8.0, 6.2, 1 H),
7.22 (d, J ) 8.1, 1 H), 7.18 (d, J ) 7.0, 1 H), 7.08 (t, J ) 7.1,
1 H), 6.94 (td, J ) 8.4, 2.4, 1 H), 6.85 (d, J ) 8.3, 1 H), 5.87 (s,
1 H), 4.33 (q, J ) 7.3, 1 H), 3.78 (s, 1 H), 1.56 (d, J ) 7.3, 3 H),
1.51 (s, 3 H), 1.24 (s, 3 H); 13C NMR (CDCl3) 214.0, 162.4 (d,
J ) 244.0), 152.3, 147.0, 144.2, 137.2 (d, J ) 8.1), 129.8 (d, J
) 8.8 Hz), 128.7, 128.0, 125.4, 124.2, 123.0, 122.6, 122.4, 121.9,
121.8, 118.1, 116.5, 115.8 (d, J ) 23.1), 114.1, 113.8 (d, J )
21.1), 60.1, 44.9, 27.7, 27.2, 17.4. Anal. (C26H22FNO2) C, H, N.
(R ,S)-(Z)-5-Be n zylid e n e -1,2,3,4-t e t r a h yd r o-2,2,4-t r i-
m eth yl-5H-ch r om en o[3,4-f]qu in olin -3-on e (29). This com-
pound was prepared from compound 27 (20 mg, 0.049 mmol)
and benzylmagnesium bromide ether solution (0.10 mL, 1.0
M, 0.10 mmol) by the same procedure as described in the
synthesis of compound 28 in a 40% two-step yield as a colorless
oil (7.5 mg): 1H NMR (CDCl3) 7.81 (d, J ) 7.3, 2 H), 7.72 (d,
J ) 7.7, 1 H), 7.59 (d, J ) 8.4, 1 H), 7.39 (t, J ) 7.3, 2 H),
7.24-7.18 (m, 2 H), 7.17 (d, J ) 7.7, 1 H), 7.08 (t, J ) 7.7, 1
H), 6.83 (d, J ) 8.4, 1 H), 5.91 (s, 1 H), 4.37 (q, J ) 7.3, 1 H),
3.76 (s, 1 H), 1.57 (d, J ) 7.3, 3 H), 1.51 (s, 3 H), 1.24 (s, 3 H);
13C NMR (CDCl3) 214.1, 152.7, 146.0, 144.2, 135.1, 129.5,
128.6, 128.5, 127.1, 124.2, 122.8, 122.4, 122.2, 121.8, 121.7,
Incubation of the T47D cells in the presence of test compound
stimulates expression of alkaline phosphatase, and the absor-
bency was measured. All the experiments were carried out in
96-well plates by automation (Beckman Biomomek automated
workstation).
Ack n ow led gm en t. The authors would like to thank
Dr. J ian Wang for a helpful discussion regarding the
charge distribution, dipole moment, and direction dif-
ferences between the new progestins and compound 1
series.
Refer en ces
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X.-N.; Marschke, K. B.; Kong, J . W.; Farmer, L. J .; and J ones,
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(8) The oxidation rate of isomer 13 with PCC was much faster than
that of 14 due to the steric hindrance imposed by the 5-aryl
group.
117.8, 116.5, 115.4, 60.1, 44.9, 27.7, 27.2, 17.4. Anal. (C26H23
NO2) C, H, N.
-
(9) Without the N-t-Boc protection the Grignard reagent added
nondiscriminately to both the lactone and the 3-ketone.
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Cotr a n sfection Assa ys. The function and detailed prepa-
ration procedure of the cotransfection assays have been
described previously.10 The agonist activity was determined
by examining the LUC expression (normalized response) and
the efficacy readout was a relative value to the maximal LUC
expression produced by a reference agonist, e.g., progesterone
for hPR. All the cotransfection experiments were carried out
in 96-well plates by automation (Beckman Biomomek auto-
mated workstation).
R ecep t or Bin d in g Assa ys. The preparation of receptor
binding assays for hPR-A, hGR, and hAR was described
previously,11 and the radioligands used in the competitive
binding assays are progesterone for hPR-A, dihydrotestoster-
one for hAR, and dexamethasone for hGR.
(11) Pathirana, C.; Stein, R. B.; Berger, T. S.; Fenical, W.; Ianiro,
T.; Mais, D.; Torres, A.; Glodman, M. E. Nonsteroidal Human
Progesterone Receptor Modulators from the Marine Alga Cy-
mopolia barbata. Mol. Pharmacol. 1995, 47, 630-635.
T47D Alk a lin e P h osp h a ta se Assa y. The T47D alkaline
phosphatase assays were performed as described previously.10
J M980723H