A concise synthesis of 1,4-dihydro-[1,4]diazepine-5,7-dione, a novel 7-TM receptor ligand core structure with melanocortin receptor agonist activity

Article abstract of DOI:10.1016/j.bmc.2010.01.049

Finding small non-peptide molecules for G protein-coupled receptors (GPCR) whose endogenous ligands are peptides, is a very important task for medicinal chemists. Over the years, compounds mimicking peptide structures have been discovered, and scaffolds e

Full text of DOI:10.1016/j.bmc.2010.01.049

Bioorganic & Medicinal Chemistry 18 (2010) 1822–1833
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
A concise synthesis of 1,4-dihydro-[1,4]diazepine-5,7-dione, a novel 7-TM
receptor ligand core structure with melanocortin receptor agonist activity
d
a
c
c
Jerzy R. Szewczyk a, , Chris P. Laudeman , Doug M. Sammond , Manon Villeneuve , Douglas J. Minick ,
*
Mary K. Grizzle b, Alejandro J. Daniels b, John L. Andrews b, Diane M. Ignar b
a Department of Medicinal Chemistry, Five Moore Drive, PO Box 13398, Research Triangle Park, NC 27709-3398, United States
b Department of Metabolic Diseases, Five Moore Drive, PO Box 13398, Research Triangle Park, NC 27709-3398, United States
c Department of Analytical Chemistry GlaxoSmithKline, Five Moore Drive, PO Box 13398, Research Triangle Park, NC 27709-3398, United States
d Seachaid Pharmaceuticals, Inc. 801 Capitola Drive, Ste. 5 Durham, NC 27713, United States
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 9 June 2008
Revised 16 January 2010
Accepted 20 January 2010
Available online 25 January 2010
Finding small non-peptide molecules for G protein-coupled receptors (GPCR) whose endogenous ligands
are peptides, is a very important task for medicinal chemists. Over the years, compounds mimicking
peptide structures have been discovered, and scaffolds emulating peptide backbones have been designed.
In our work on GPCR ligands, including cholecystokinin receptor-1 (CCKR-1) agonists, we have employed
benzodiazepines as a core structure. Looking for ways to reduce molecular weight and possibly improve
physical properties of GPCR ligands, we embarked on the search for molecules providing similar scaffolds
to the benzodiazepine with lower molecular weight. One of our target core structures was 1,4-dihydro-
[1,4]diazepine-5,7-dione. There was not, however, a known synthetic route to such molecules. Here we
report the discovery of a simple and concise method for synthesis of 2-[6-(1H-indazol-3-ylmethyl)-5,7-
dioxo-4-phenyl-4,5,6,7-tetrahydro-[1,4]diazepin-1-yl]-N-isopropyl-N-phenyl-acetamide as an example
of a compound containing the tetrahydrodiazepine-5,7-dione core. Compounds from this series were
tested in numerous GPCR assays and demonstrated activity at melanocortin 1 and 4 receptors (MC1R
and MC4R). Selected compounds from this series were tested in vivo in Peptide YY (PYY)-induced food
intake. Compounds dosed by intracerebroventricular and oral routes reduced PYY-induced food intake
and this effect was reversed by the cyclic peptide MC4R antagonist SHU9119.
Keywords:
G protein-coupled receptors
Agonist
MC4R
MC1R
Tetrahydrodiazepine-5,7-dione
Food intake
Ó 2010 Published by Elsevier Ltd.
1. Introduction
2. Results and discussion
Identifying small molecule non-peptide agonists for receptors
for which a peptide is the endogenous ligand, has been a very
important undertaking for medicinal chemists. For many years,
morphine and related opioids were the only examples of non-pep-
tide ligands for peptide receptors. Discovery in the last decade of
non-peptide agonists for angiotensin II,1 growth hormone secreta-
gogues2–4 cholecystokinin receptors5 and melanocortin recep-
tors6,7 has changed the landscape.
At GSK, we have employed benzodiazepine as a core for our CCK
R-1 agonists.8–10 In the search for an alternative template provid-
ing a similar arrangement of substituents to benzodiazepine, we
turned our interest to tetrahydrodiazepines-5,7-diones. Unfortu-
nately compounds with this core structure have not been de-
scribed in the chemical literature. Retrosynthetic analysis led us
to propose the following (Scheme 1) approach.
2.1. Chemistry
We decided to utilize the reaction between an aldehyde diacetal
and an amide as a critical step for seven-membered ring closure. A
similar approach was also used by others in the synthesis of six
membered rings.11,12
Compound 7 was prepared via a short synthesis beginning with
the reaction of 2-(N-anilino)acetaldehyde diethyl acetal 1 with
methyl malonylchloride 2 in the presence of base, to give amide
3 in 75% yield. Subsequent ester hydrolysis afforded the malonic
mono-amide, mono-carboxylic acid 4 in 98% yield (Scheme 2).
Separately, 2-bromo-N-isopropyl-N-phenyl-acetamide was pre-
pared by a previously described method.10 Aminolysis of the 2-bro-
moacetamide 5 afforded the N-substituted glycine amide 6 in 88%
yield (Scheme 3).
Coupling of the malonic mono-amide mono-carboxylic
acid 4 with the N-substituted glycine amide 6, in the presence of
1 equiv of EDC, yielded compound 7 in 85% yield. Subsequent
* Corresponding author. Tel.: +1 919 408 0512.
E-mail address: kjszewczyk@verizon.net (J.R. Szewczyk).
0968-0896/$ - see front matter Ó 2010 Published by Elsevier Ltd.
doi:10.1016/j.bmc.2010.01.049

J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
1823
R1
MeO
O
O
N
O
R1
N
H
O
O
O
MeO
Cl
O
R2
N
R2
R3
N
O
R3
N
O
O
O
R3
O
Scheme 1.
MeO
O
O
OMe
O
N
O
MeO
+ O
O
Ph
Base
H O/OH
2
N
O
N
N
O
Ph
Ph
TosOH/Toluene
O
O
1
2
Cl
3
9
4
O
O
O
N
N
Ph
Scheme 2.
O
N
OMe
10
N
O
O
OMe
OMe
N
O
O
NH
3
N
N
N
O
O
5
6
NH
N
Ph
Br
2
O
N
N
Scheme 3.
11
Scheme 5.
alkylation of the compound 7 with tert-butyl 3-(bromomethylene)-
1H-indazole-1-carboxylate 8 (prepared as described previously)9
provided
(Scheme 4).
a
racemic mixture of compound
9
in 78% yield
receptor-selective compounds, we embarked on development of
SAR around this series to obtain MC1R- and MC4R-selective com-
pounds. We used an identical synthetic route to synthesize all
racemic compounds listed in Table 1 (compounds 11–35). Enanti-
omers 11-(S) and 11-(R) were isolated by chiral preparative HPLC
Treatment of compound 9 with anhydrous p-toluenesulfonic
acid in toluene led to the acid-catalyzed reaction of the acetal
and the amide resulting in cyclization to give the 2,4-dioxo-1,5-
diazepine compound 10 in 93% yield. Treatment of compound 10
with trifluoroacetic acid in methylene chloride afforded diazepine
11 in 95% yield. Alternatively treatment of compound 9 with p-tol-
uenesulfonic acid hydrate in toluene provided final product 11
(69% yield) in a one step conversion (Scheme 5).
of the respective racemic mixtures. Relative to a-MSH, compounds
tended to be both more potent and efficacious at MC1R, thus the
greater challenge was to find molecules that are selective for
MC4R. Further, SAR for MC4R was very narrow, and even small
changes caused loss of agonist activity. However, some trends
did emerge.
2.2. SAR
We have found that the acetanilide moiety at N-1 could be
modified in a number of ways: para substitution of the phenyl ring
with small groups (OMe, OCF3, OH, F) enhanced activity on both
receptors, but the large polar group morpholine led to a loss of
Compound 11 was tested in numerous GPCR assays and showed
agonist activity at MC1R and MC4R. Since it is important to have
OMe
OMe
N
N
O
O
O
O
O
Br
N
O
N
O
N
EDC
base
N
4 +
6
N
+
N
O
O
O
N
O
N
O
O
Ph
Ph
8
9
7
O
Scheme 4.

1824
J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
Table 1
SAR table for MC4R and MC1R agonist activity in reporter gene assays
R1
O
H
O
O
N
R2
R3
H
N
R4
#
R1
R2
R3
R4
MC4R
MC1R
pEC50
% of alpha-MSH
pEC50
7.53
% of alpha-MSH
O
X2
X4
CH3
CH3
N
11
H
6.15
45
68
H3C
N
N
X
1
11-(S)
11-(R)
Enantiomer S of compound 11
Enantiomer R of compound 11
4.50
6.47
14*
53
5.81
7.80
28
82
X2
X4
N
12
H
H
6.36
16
8.80
61
N
N
F
X1
X2
X4
N
13
6.49
17
8.80
61
N
N
X1
13-(S)
13-(R)
Enantiomer S of compound 13
Enantiomer R of compound 13
6.10
7.00
20
27
7.21
8.80
76
86
X2
X4
X4
X4
CH3
14
H
H
5.49
22
6.15
42
N
N
CH3
N
N
X1
14-(S)
14-(R)
Enantiomer S of compound 14
Enantiomer R of compound 14
4.50
5.97
3*
26
4.50
6.53
9*
54
X2
CH3
F
15
6.27
19
6.73
51
N
N
CH3
X1
15-(S)
15-(R)
Enantiomer S of compound 15
Enantiomer R of compound 15
4.50
5.90
0*
23
4.50
7.45
2*
79
O
N
X2
H3C
N
X1
N
16
H
6.45
39
8.80
83
H3C CH3
F
F
X2
X2
X2
X4
X4
X4
CH3
N
17
18
19
H
H
H
6.55
6.75
6.00
22
19
30
7.30
7.85
6.26
54
53
54
N
CH3
F
N
X1
CH3
N
N
H3C
H3C
N
N
F
X1
OH
CH3
N
N
X1
19-a
19-b
1st Enantiomer of compound 19
2nd Enantiomer of compound 19
6.00
4.50
44
5*
6.80
7.28
79
16

J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
1825
Table 1 (continued)
#
R1
R2
R3
R4
MC4R
MC1R
pEC50
% of alpha-MSH
pEC50
6.75
% of alpha-MSH
O
O
X4
CH3
CH3
CH3
X2
20
H
5.54
31
16
60
H3C
H3C
N
N
N
N
X1
X2
X4
X3
CH3
N
N
21
22
23
24
5.98
6.18
7.35
4.50
6.40
7.90
5.53
4.50
30
65
33
0*
N
N
N
X1
X4
F
O
CH3
CH3
X2
X2
H
31
52
0*
H3C
F
N
N
N
N
X1
N
X
X4
X4
X4
3
CH3
N
O
CH3
N
CH3
O
X1
X2
CH3
CH3
H
H
H3C
O
N
X1
N
X2
CH3
25
4.50
3*
6.08
22
N
N
N
CH3
X1
O
O
N
X4
X2
CH3
CH3
N
26
27
28
H
H
H
4.50
4.50
4.50
19*
10*
6*
4.50
5.93
6.10
25*
H3C
N
X1
X4
CH3
CH3
X2
43
H3C
N
S
N
N
N
X1
H3C
X4
CH3
X2
N
59
X1
N
H3C
H3C
O
F
N
X4
N
O
CH3
F
X2
F
29
30
H
6.82
6.78
78
74
7.65
5.86
91
58
N
X1
O
X2
N
O
X4
CH3
CH3
X3
CH3
N
H3C
N
X1
X2
X4
N
O
P
5*
4.50
1*
N
31
H
4.50
O
O
(continued on next page)

1826
J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
Table 1 (continued)
#
R1
R2
R3
R4
MC4R
MC1R
pEC50
% of alpha-MSH
pEC50
4.50
% of alpha-MSH
O
O
X4
X4
X4
H3C
CH3
32
H
4.50
5*
6*
N
CH3
N
CH3
X2
N
X1
H3C
CH3
CH3
33
34
H
H
4.50
4.50
5*
4.50
4.50
2*
N
CH3
N
X1
X2
X2
N
O
P
O
4*
3*
N
N
O
F
F
X4
CH3
CH3
5*
5.43
62
N
H3C
35
H
4.50
X1
N
X2
N
4.5 Denotes that EC50 is higher than 30 lM.
*
Denotes efficacy at 10 lM.
MC4R activity while only slightly diminishing MC1R activity. Mod-
ification from the isopropyl phenyl amide to 2,3,4,5-tetrahydro-
1H-benzazepine did not dramatically affect MC4R activity but led
to compounds such as number 12 with high potency on MC1R.
With pEC50 = 8.8 on MC1R, these compounds demonstrated
>100-fold selectivity over MC4R. An isosteric phosphonate group
in place of the anilide moiety at N-1 rendered compounds inactive
on both receptors. We found even less tolerance for changes at N-4.
A simple phenyl group is preferred at N-4. While substantial
changes are tolerated for MC1R, only a pyridyl group preserved
some MC4R activity. Replacing phenyl with cyclohexyl resulted
in a total loss of activity at both MC4R and MC1R. Changing to
Figure 1. VCD (upper panel) and IR spectra (lower panel) observed for compound 11-(R) are compared with corresponding spectra calculated for the reduced-structure
*
model (Fig. 2). The 10 VCD ‘marker’ bands were used to make the configurational assignments in this study. Absorption bands identified by ( ) in the experimental IR data are
due to vibrational modes of the functional groups omitted from the model. The band near 1125 cmꢀ1 in the calculated IR spectrum is due to the N,N-dimethyl group (C–N
stretch) in the model.

J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
1827
benzyl and to a lesser extent 2-thienylmethyl, seen in compounds
27 and 28, retained some MC1R activity but abolished all MC4R
activity. Truncation to methyl at N-4 gave a compound with weak
activity on only MC1R. While modifications at N-1 and N-4 pro-
vided compounds selective for MC1, changes at C-6 led to com-
pounds with enhanced selectivity for MC4R over MC1R.
and were first identified in the calculated IR and VCD spectra, then
assigned in experimental data. In the upper panel of this figure, the
signs of the marker bands are the same in the VCD spectra of com-
pound 11-(R) and the model, indicating that this molecule has the
same absolute configuration as the model. In the comparison of
compound 11-(S) and the model (not shown), the 10 VCD marker
bands were oppositely signed, indicating that the stereocenter in
this molecule is the mirror image of the model. Based on these re-
sults, compound 11-(S) was assigned as the (6S)-enantiomer and
compound 11-(R) as the (6R)-enantiomer (Fig. 3).
The indazole at C-6 was found to be necessary for activity. So,
for the purposes of this study, substituents at C-6 were limited to
primarily 1H-indazol-3-ylmethyl and its 6-fluoro analog. The pres-
ence of the 6-fluoro substituent on the indazole group tended to
increase potency at both MC4R and MC1R. This was especially
the case when the p-methoxy anilide at N-1 was incorporated
along with the 6-fluoro indazole at C-6 which provided compound
16 with pEC50 = 8.80 at MC1R. However, introduction of a methoxy
group at C-6 along with the 1H-indazol-3-ylmethyl moiety led to
compounds with 10–50-fold selectivity for MC4R. The greatest
enhancement of MC4R activity was seen when the p-fluoro anilide
was utilized rather than the p-methoxy anilide at N-1. With the
addition of the methoxy group at C-6, seen in compound 23, this
provided a sixfold increase in potency for MC4R while diminishing
activity at MC1R nearly 60-fold. Introduction of a larger group, 1H-
pyrazol-3-ylmethyl, led to decreased activity at both receptors. The
greatest impact of this change was on MC1R with over 10-fold de-
2.4. In vivo activity
11-(R) (10 mg/kg) was orally administered to Sprague Dawley
rats as a suspension in 50% PEG/25% EtOH/25% H2O and plasma
samples were taken to generate a pharmacokinetic profile (Table
2). Compound 37 had low oral bioavailability and exposure and a
short half-life.
In order to test the efficacy and MC4R-specificity of compound
11 [racemic mixture containing 11-(R)], 1 nmol SHU9119, an cyclic
peptide MC4R antagonist (Ac-Nle-c[Asp-His-DNal(20)-Arg-Trp-
Lys]-NH2), was administered by intracerebroventricular (ICV)
injection to lean rats 30 min before ICV administration of vehicle
or 100 pmol compound 11. Later (15 min), peptide YY (PYY), an
orexigenic agent, was administered ICV and food intake was mon-
itored for 3 h. Compound 11 significantly inhibited PYY-induced
food intake during the course of the study and this effect was com-
pletely reversed by SHU9119 (Fig. 4).
Oral administration of 5 or 25 mg/kg of compound 11-(R) to sa-
ted lean rats antagonized the orexigenic effect of subsequent ICV
administration of 0.23 nmol PYY ( Fig. 5). In the vehicle group,
PYY administration induced food intake during the light cycle per-
iod when rats are normally inactive with respect to food intake.
Both doses of compound 11-(R) inhibited PYY-induced food intake
to the same extent. The natural cycle of nocturnal feeding began at
6 PM when lights were turned off and continued until lights were
turned on at 6 AM. During this period, the 25 mg/kg dose of com-
pound 11-(R) continued to fully suppress food intake.
In contrast to these observations, administration of 25 mg/kg
11-(R) to lean rats only mildly suppressed food intake (ꢁ20%)
when given just prior to the onset of nocturnal cycle (data not
shown). The mechanism underlying this discrepancy between effi-
cacy observed with or without PYY treatment is not understood.
crease in potency relative to
a-MSH. To explore the effects of the
chirality at C-6, several racemic mixtures were resolved to give
the stereoisomers of the following compounds 11, 13, 14, 15, and
19. In most cases only one enantiomer was found to be active on
MC4R, and the same enantiomer was more potent at MC1R. A nota-
ble exception is compound 19b which had no measurable activity
on MC4R but was found to have pEC50 = 7.3 on MC1R.
2.3. Vibrational circular dichroism calculation
In order to advance our understanding of the SAR of these com-
pounds, we sought to determine the absolute configurations of
compounds 11-(S) and 11-(R), the enantiomers of compound 11
(Scheme 5). The absolute configurations of these molecules were
assigned by ab initio vibrational circular dichroism (VCD) using
the reduced-structure model shown in Figure 2. Reduced-structure
modeling has been used successfully in VCD studies of larger mol-
ecules,13b,14 and was used here to allow VCD calculations to be car-
ried out at a higher level of theory, increasing the reliability of the
simulated VCD spectrum. The VCD and IR spectra calculated for the
reduced-structure model are compared in Figure 1 with experi-
mental data observed for compound 11-(R). In the upper panel of
the Figure 1, the calculated VCD spectrum is in very good qualita-
tive agreement with experimental, indicating good characteriza-
tion of the conformational state surrounding the chiral center
and assuring reliable stereochemical assignments. As expected,
the overall qualitative agreement between IR spectra is not as good
due to replacement of the 4-methoxyphenyl and isopropyl groups
in with methyl groups in the model.
NH
NH
N
N
O
O
O
O
O
O
N
N
N
N
N
N
O
O
A set of 10 bands are labeled in all spectra shown in Figure 1.
These ‘marker’ bands are due to vibrational modes of functional
groups in common with both the model and compound 11-(R)
11-(R)
(6R)-diazepine
11-(S)
(6S)-diazepine
Figure 3.
NH
N
O
O
Table 2
PK properties of 11-(R)
N
N
N
Dose
mg/kg
10
Cmax
(ng/mL)
Tmax (h)
AUCinf
(h nf/mL)
Bioavail (%)
6.2
t1/2 (h)
O
Route
PO
Figure 2. Reduced structured model: 2-[(6R)-(1H-Indazol-3-ylmethyl)-5,7-dioxo-
4-phenyl-4,5,6,7-tetrahydro-[1,4]diazepin-1-yl]-N,N-dimethyl-acetamide.
123
0.67
260
1.5

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J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
compounds more potent at MC1R, we established that addition
7
6
5
4
3
2
1
0
Veh/Veh
Veh/11
of a methoxy group at C-6 imparts significant MC4R selectivity.
Further, the chirality at C-6 was found to strongly influence both
potency and efficacy. This finding of the necessary geometry at this
position will inform future SAR elucidation, and all reported find-
ings can now be combined in the hope of finding more potent
and selective agonists for MC4R. It is clear that additional work is
necessary to fully determine the scope of SAR for diazepinediones,
and future work will include in vivo evaluation of compounds in
this class.
SHU/Vehicle
SHU/11
4. Experimental
4.1. Receptor pharmacology
Figure 4. Vehicle (saline) or 1 nmol SHU9119 was administered 30 min before
vehicle (2% DMSO/saline) or 100 pmol of compound 11. Later (15 min), 0.23 nmol
PYY was administered to all rats. Treatments were administered ICV. N = 7–8 per
group. Compound 11 significantly suppressed PYY-induced food consumption at all
time points from 60 min to end of study (p <0.05).
Reporter gene assays for melanocortin receptors were per-
formed as described previously.15 CHO-6xCRE-luc+ reporter cell
lines expressing human MC1R, MC3R, MC4R, and MC5R and host
cell line were harvested with trypsin 48 h prior to assay and plated
at 4000 cells/well in DMEM/F12 with 10% FBS in 96 well plates.
Prior (16 h) to the assay, the medium was replaced with 90
of serum-free DMEM/F12. At the time of the assay the compounds
were added in a 10 l volume and plates were incubated for 4 h at
37 °C in a cell culture incubator. Medium was then aspirated and
50
L of 1:1 mixture of LucLiteÒ and dPBS/1 mM CaCl2/1 mM
MgCl2 was added. Plates were sealed and subjected to dark adap-
tation at room temperature for 10 min before luciferase activity
was quantitated on a TopCount™ microplate scintillation counter
(Packard) using 3 s/well count time. Compound activity was ex-
ll/well
l
35
Vehicle
l
30
25
20
15
10
5
5 mg/kg
25 mg/kg
pressed as a percentage of the fold stimulation of NDP-aMSH
(melanocyte-stimulating hormone) control for each receptor sub-
type. The control value is the average of duplicate wells treated
with 1 ꢂ 10ꢀ7 M NDP-
aMSH.
4.2. Food consumption experiments
0
Lean Sprague-Dawley rats weighing approximately 400 g were
fitted with indwelling cannula in the third ventricle (Charles River
Laboratories, Raleigh, NC). Food consumption was monitored every
half hour in cages fitted with accuscan systems (AccuScan Instru-
ments Inc., DietMax Food Consumption System, Columbus, OH).
Rats were acclimated to the chambers and powdered standard lab-
oratory chow (Purina Chow 5001 Richmond, IN). Animals were
handled prior to study by removing from chamber, placement in
cage where injections occur, removing headcap and manipulating
cannula.
Figure 5. Vehicle (50% PEG500, 25% EtOH, 25% water) or compound 11-(R) were
administered by oral gavage at 10:30 AM. 0.23 nmol of PYY was administered ICV to
all rats at 11:00 AM. The dark cycle started at 6 PM and ended at 6 AM. N = 5/group.
Both 5 and 25 mg/kg of compound 11-(R) significantly suppressed food consump-
tion during the entire experiment (p <0.05).
In Figure 4, the vehicle for 11 was sterile saline containing 2%
DMSO. PYY (Quality Controlled Biochemicals, Hopkinton, MA)
and SHU9119 were dissolved in sterile water for ICV delivery. Vol-
One possibility could be that the presence of PYY during the day-
light hours reduces the sensitivity of the system to orexigenic fac-
tors during the dark cycle rendering the MC4R agonist more
effective than in the basal state.
umes of injection were 1 ll for PYY and SHU9119 and 2 ll for 11.
In Figure 5, the vehicle for oral administration of compound 11-(R)
was 50% PEG500/25%ETOH/25% water, PYY was delivered ICV in
sterile saline water.
3. Conclusions
All procedures were performed in compliance with the Animal
Welfare Act, USDA regulations and approved by the GlaxoSmithK-
line Institutional Animal Care and Use Committee. Animals were
housed at 72 F and 50% relative humidity with a 12-h light and
dark cycle.
MC4R is expressed in areas of the brain thought to be involved
in control of food consumption. Inactivation of receptor activity
through mutation results in obesity in rodents and humans, thus,
agonists of MC4R are being sought as therapeutics for obesity. In
addition to expression in melanocytes, MC1R is also expressed on
immune cells such as macrophages and is thought to mediate
the anti-inflammatory effect of MSH.
4.3. Analytical chemistry
We report in this manuscript, the development of a new and
concise method for the synthesis of tri-substituted diazepinedi-
ones, a novel class of compounds with agonist activity at MC1R
and MC4R. While this particular scaffold consistently provided
VCD and IR spectra were acquired in the mid-infrared region
(2000–950 cmꢀ1) using a Chiralir™ VCD spectrometer (Bomem/
BioTools) equipped with a dual photoelastic modulator (dual
PEM). Spectra were acquired at 4 cmꢀ1 resolution with a scan

J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
1829
speed of approx. 50 scans per minute. The unpolarized IR spectrum
4.4.4. N-(2,2-Diethoxyethyl)-N-phenylamino 2-[N’-isopropyl-
and accompanying VCD spectrum were acquired for 12 and
180 min, respectively. Samples were dissolved in CDCl3 at a con-
centration of 58 mg/mL and spectral measurements made using a
sealed transmission cell with BaF2 windows, a 0.1-mm pathlength
and an internal volume of approximately 75 ll. The measured VCD
spectra (VCDobs) were corrected for baseline artifacts by subtract-
(N’-4-methoxyphenylamino)-2-oxoethyl] Malonamide (7)
A solution of 0.6 g (2 mmol) of N1-isopropyl-N1-(4-methoxy-
phenyl)glycinamide (6), 0.53 g (2 mmol) of 3-[(N-2,2-diethoxyeth-
yl)-N-phenyl]amino-3-oxopropanoic acid (4) and 0.31 g of HOBT in
DMF (5 ml) was cooled to 0 °C and 0.47 g of EDC was added in one
portion. The reaction mixture was stirred overnight and poured
into ice water and were extracted with ethyl acetate (3 ꢂ 15 ml).
The combined organic layers were dried with anhydrous MgSO4,
concentrated in vacuo and purified by column chromatography
on silica gel (1% MeOH/99% CHCl3), providing 900 mg (89%) of
compound (7). 1H NMR (300 MHz, CDCl3) 8.21 (m, 1H), 7.28 (m,
6H), 6.99 (m, 2H), 6.88 (m, 2H), 4.95 (sept., J = 7 Hz, 1H), 4.80 (t,
J = 5.6 Hz, 1H), 3.81 (s, 3H), 3.78 (m, 2H), 3.54 (m, 6H), 3.03 (s,
2H), 1.13 (t, J = 7 Hz, 6H), 1.03 (d, J = 7 Hz, 6H).
ing the enantiomer spectra from each other:
1=2f½VCDobsðꢀÞꢃ ꢀ ½VCDobsðþÞꢃg and 1=2f½VCDobsðþÞꢃ
ꢀ ½VCDobsðꢀÞꢃg
Due to the relatively large size of these optical isomers, the re-
duced-structure model in Figure 2 was used instead of a full struc-
ture model. Geometry optimizations, harmonic vibrational
frequencies, and VCD/IR intensities were calculated with the
B3LYP density functional using the 6-311G(d,p) basis set. Calcula-
tions were carried out with the GAUSSIAN ‘03 (G03) program pack-
age.16 For comparison with experimental, calculated vibrational
frequencies were scaled using a uniform scaling factor of 0.98,
and calculated IR and VCD line intensities converted to Lorentzian
bands with 6 cmꢀ1 half-width-at-half-height. Composite VCD and
IR spectra were generated using the fractional populations of five
model conformers estimated by Boltzmann statistics.13
4.4.5. N-(2,2-Diethoxyethyl)-N-phenylamino 2-[N’-Isopropyl-
(N’-4-methoxyphenylamino)-2-oxoethyl] 2-(1-tert-
butyloxycarbonyl-1H-indazol-3-ylmethylene)malonamide (9)
To a solution of 680 mg (1.36 mmol) of N-(2,2-diethoxyethyl)-
N-phenylamino 2-[N’-isopropyl-(N’-4-methoxyphenylamino)-2-
oxoethyl] malonamide (7) in dry DMF (5 ml), 2.74 ml of 0.5 M solu-
tion of potassium bis(trimethylsilyl)amide in toluene was added at
0 °C. The reaction mixture was stirred for 30 min at 0 °C and a solu-
tion of 423 mg (1.36 mmol) of tert-butyl 3-(bromomethylene)-1H-
indazole-1-carboxylate (8) in dry DMF (2 ml) was added dropwise.
The reaction mixture was stirred overnight at room temperature,
poured into water and this mixture was extracted with ethyl ace-
tate (2 ꢂ 15 ml). The organic phase was separated and dried. The
solvent was removed in vacuo and the residue was purified by col-
umn chromatography on silica gel (MeOH 1%/CHCl3 99%) to afford
700 mg (71% yield) of product. 1H NMR (400 MHz, CDCl3) 8.05 (d,
J = 8 Hz, 1H), 7.64 (d, J = 8 Hz, 1H), 7.46 (m, 1H), 7.12 (m, 11H),
4.95 (sept., J = 7 Hz, 1H), 4.60 (t, J = 5.6 Hz, 1H), 3.88 (m, 1H), 3.81
(s, 3H), 3.68 (m, 3H), 3.52 (m, 5H), 3.24 (m, 2H), 1.70 (s, 9H),
1.03 (m, 12H).
4.4. Chemistry
4.4.1. Methyl 3-[(N-2,2-diethoxyethyl)-N-phenyl]amino-3-
oxopropanoate (3)
A solution of 1.1 g (8.1 mmol) of methyl malonyl chloride (2) in
chloroform (10 ml) was added to a solution of 1.67 g (8 mmol) of 2-
(N-anilino)acetaldehyde diethyl acetal (1) and 0.79 g of pyridine in
chloroform (20 ml) at 0 °C. The reaction mixture was stirred for 2 h,
evaporated and the residue purified by column chromatography on
silica gel (hexane 50%/ethyl acetate 50%), to afford 2 g (80%) of the
titled product (3). 1H NMR (300 MHz, CDCl3): 7.38 (m, 3H); 7.26
(m, 2H), 4.82 (t, J = 5.6 Hz, 1H), 3.80 (d, J = 5.6 Hz, 2H), 3.67 (s,
3H), 3.60 (m, 4H), 3.20 (s, 2H), 1.16 (t, J = 7 Hz, 6H).
4.4.6. 2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-5-phenyl-
2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-isopropyl-N-(4-
methoxyphenyl)acetamide (10)
A solution of 200 mg (0.27 mmol) of N-(2,2-diethoxyethyl)-N-
phenylamino 2-[N’-isopropyl-(N’-4-methoxyphenylamino)-2-oxo-
4.4.2. 3-[(N-2,2-Diethoxyethyl)-N-phenyl]amino-3-
oxopropanoic acid (4)
ethyl]
2-(1-tert-butyloxycarbonyl-1H-indazol-3-ylmethylene)
To a solution of 2.0 g (6.5 mmol) of methyl 3-[N-(2,2-diethoxy-
ethyl)-N-phenyl]amino-3-oxopropanoate (3) in THF (10 ml) and
water (5 ml), 3.4 ml of 1 N aqueous solution of NaOH was added
and resultant mixture was stirred overnight at room temperature.
THF was removed in vacuo and 1 N aqueous solution of NaHSO4
(3.5 ml) was added. The product was extracted with ethyl acetate
(2 ꢂ 50 ml). The organic layers were combined, dried with anhy-
drous MgSO4 and the solvent removed in vacuo to afford 1.87 g
(98%) of product (4). 1H NMR (300 MHz, CDCl3) 7.38 (m, 3H),
7.26 (m, 2H), 4.82 (t, J = 5.6 Hz, 1H), 3.80 (d, J = 5.6 Hz, 2H), 3.67
(s, 3H), 3.60 (m, 4H), 3.20 (s, 2H), 1.16 (t, J = 7 Hz, 6H),
malonamide (9) and p-toluenesulfonic acid (anhydrous, 20 mg) in
dry toluene (80 ml) was placed in an oil bath at 70 °C and stirred
for 30 min. Toluene was removed in vacuo and the residue was
purified by column chromatography on silica gel (hexane 50%/
ethyl acetate 50%) to afford 170 mg (98% yield) of product (10).
1H NMR (400 MHz, CDCl3) 8.03 (d, J = 8.4 Hz, 1H). 7.85 (d,
J = 8 Hz, 1H), 7.47 (t, J = 7.7 Hz, 1H), 7.31 (m, 6H), 7.11 (m, 2H),
6.93 (m, 2H), 6.00 (s, 2H), 4.95 (sept., J = 6.7 Hz, 1H), 4.35 (d–d,
J = 8.9 Hz, J = 4.8 Hz, 1H), 3.93 (m, 2H), 3.85 (d–d, J = 16.6 Hz,
8.9 Hz, 1H), 3.82 (s, 3H), 3.58 (d–d, J = 16.6 Hz, J = 4.8 Hz, 1H),
1.65 (s, 9H), 1.04 (d, J = 6.7 Hz, 6H).
4.4.3. N1-Isopropyl-N1-(4-methoxyphenyl)glycinamide (6)
2.86 g (10 mmol) of 2-Bromo-N-isopropyl-N-(4-methoxy-
phenyl)acetamide (5) was dissolved in methanol saturated with
ammonia at 0 °C and left for 3 days at room temperature in a
sealed flask. Methanol and ammonia were removed in vacuo and
the residue was dissolved in chloroform (100 ml) and washed with
water (2 ꢂ 50 ml). The organic layer was separated and dried with
anhydrous MgSO4 and concentrated in vacuo to afford 1.95 g (88%)
of compound (6). 1H NMR (300 MHz, CDCl3) 6.96 (m, 4H), 4.99
(sept., J = 6.6 Hz, 1H), 3.84 (s, 3H), 2.97 (s, 2H), 1.58 (s, 2H), 1.05
(d, J = 6.6 Hz, 6H).
4.4.7. 2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-5-phenyl-
2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-isopropyl-N-(4-
methoxyphenyl)acetamide (11)
170 mg (0.27 mmol) of 2-[2,4-dioxo-3-(1-tert-butyloxycar-
bonyl-1H-indazol-3-ylmethylene)-5-phenyl-2,3,4,5-tetrahydro-1H-
1,5-diazepin-1-yl]-N-isopropyl-N-(4-methoxyphenyl)acetamide
(10) was dissolved in CHCl3 (10 ml) and TFA (5 ml) was added. The
reaction mixture was stirred for 6 h and the solvents were removed
in vacuo. The crude product was purified by RP HPLC Dynamax (C-
8) (10 ml/min (50% acetonitrile, 50% water (0.1% TFA).135 mg (94%
yield) of product (11) was obtained as a white solid. HPLC Column:

1830
J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
Dynamax C-8 2 ml/min, 30–70% Acetonitrile in aqueous TFA (0.1%
v/v) over 20 min, tR = 17.1 min. 1H NMR (400 MHz, CDCl3) 7.93 (d,
J = 8.3 Hz, 1H), 7.59 (m, 2H), 7.11 (m,2H), 7.31 (m, 6H), 6.93 (m,2H),
6.00 (s, 2H), 4.92 (sept., J = 6.3 Hz, 1H), 4.15 (m, 1H), 3.92 (m, 4H),
3.82 (s, 3H), 1.04 (d, J = 6.3 Hz, 6H).
(400 MHz, CDCl3) 7.58–7.64 (m, 1H); 7.18–7.34 (m, 5H); 7.13–
7.18 (m, 1H); 7.04–7.08 (m, 1H); 6.02 (d, J = 6.2 Hz, 1H); 5.84–
5.89 (m, 1H); 4.97 (q, J = 6.8 Hz, 1H); 4.23 (dd, J = 8.6 Hz,
J = 5.0 Hz, 1H); 4.05–4.09 (m, 1H); 3.80(s, 3H); 3.70–3.82 (m, 2H);
3.36–3.44 (m, 1H); 1.05)(d, J = 6.6 Hz, 6H). MS (ESI): M+H = 556.
MS (FAB) [M+H]+ = 538. Elemental Anal. Calcd: C, 69.26; H, 5.81;
N, 13.03. Found: C, 69.12; H, 5.78; N, 12.99.
4.4.13. 2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-5-phenyl-
2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-(4-fluorophenyl)-N-
isopropylacetamide (Compound 17)
4.4.8. 3-(6-Fluoro-1H-indazol-3-ylmethylene)-1-[2-oxoethyl-2-
(2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl)]-5-phenyl-1H-1,5-
diazepine-2,4-dione (Compound 12)
This compound was prepared as compound 11 using 2-oxo-2-
(2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl)ethanamine instead of
N1-isopropyl-N1-(4-methoxyphenyl)glycinamide and tert-butyl 3-
(bromomethyl)-6-fluoro-1H-indazole-1-carboxylate instead of of
This compound was prepared as compound 11 using N1-isopro-
pyl-N’-(4-fluorophenyl)glycinamide instead of N1-isopropyl-N1-(4-
methoxyphenyl)glycinamide. 1H NMR (400 MHz, DMSO-d6): 12.58
(s, 1H); 7.75 (d, J = 8.0 Hz, 1H); 7.22–7.44 (m, 11H); 7.05 (t,
J = 7.5 Hz, 1H); 6.16 (br s, 1H); 4.75 (q, J = 6.6 Hz, 1H); 4.14 (t,
J = 7.0 Hz, 1H); 3.98 (d, J = 6.3 Hz, 1H); 3.75 (d, J = 6.3 Hz, 1H);
3.30–3.54 (m, 3H); 0.94 (d, J = 6.8 Hz, 6H). MS (FAB) [M+H]+ = 526.
t e r t -butyl
3-(bromomethylene)-1H-indazole-1-carboxylate.
1H NMR (300 MHz, DMSO-d6) 7.83–7.91 (m, 1H); 7.22–7.50 (m,
10H); 6.95–7.01 (m, 1H); 6.28 (d, J = 6.8 Hz, 1H); 6.22 (d, J = 6.8,
1H); 4.13–4.50 (m, 3H); 3.71–3.95 (m, 1H); 3.36–3.59 (m, 2H);
2.55–2.93 (, 3H); 1.89–2.01 (m, 1H); 1.67–1.78 (m, 2H); 1.24–
1.39 (m, 1H) MS (ESI): M+H = 538.
4.4.14. 2-[2,4-Dioxo-3-(6-fluoro-1H-indazol-3-ylmethylene)-5-
phenyl-2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-(4-
fluorophenyl)-N-isopropylacetamide (Compound 18)
This compound was prepared as compound 11 using N1-isopro-
pyl-N’-(4-fluorophenyl)glycinamide instead of N1-isopropyl-N1-(4-
methoxyphenyl)glycinamide and tert-butyl 3-(bromomethyl)-6-
fluoro-1H-indazole-1-carboxylate instead of tert-butyl 3-(bro-
momethylene)-1H-indazole-1-carboxylate. 1H NMR (400 MHz,
DMSO-d6) 12.65 (s,1H); 7.77–7.82 (m, 1H); 7.16–7.4 (m, 9H);
6.86–6.96 (m, 1H); 6.16 (br s, 1H); 4.75 (m, 1H); 3.96–4.13 (m,
1H); 3.75 (d, J = 16.2 Hz, 1H); 3.24–3.50 (m, 1H); 3.29 (s, 3H);
0.94 (m, 6H). MS (ESI): M+H = 544.
4.4.9. 3-(1H-Indazol-3-ylmethylene)-1-[2-oxoethyl-2-(2,3,4,5-
tetrahydro-1H-1-benzazepin-1-yl)]-5-phenyl-1H-1,5-diazepine-
2,4-dione (Compound 13)
This compound was prepared as compound 11 using 2-oxo-2-
(2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl)ethanamine instead of
N
1-isopropyl-N1-(4-methoxyphenyl)glycinamide. 2-oxo-2-(2,3,4,
5-tetrahydro-1H-1-benzazepin-1-yl)ethanamine. 1H NMR (400
MHz, CDCl3) 7.72–7.79 (m, 1H); 7.17–7.36 (m, 11H); 7.04–7.11
(m, 1H); 5.90–6.11 (m, 2H); 4.61–4.72 (m 1H); 3.66–4.31 (m,
4H); 3.47–3.65 (m, 1H); 2.85–3.02 (m, 1H); 2.60–2.73 (m, 2H);
1.72–2.01 (m. 3H); 1.28–1.43 (m, 1H) MS (ESI): M+H = 520.
4.4.15 (2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-5-phenyl-
2,3.4.5-tetrahydro-1H-1,5-diazepin-1-yl]-N-(4-hydroxyphenyl)-
N-isopropylacetamide (Compound 19)
To the solution of 2-[2,4-dioxo-3-(1H-indazol-3-ylmethylene)-
5-phenyl-2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-isopropyl-N-
(4-methoxyphenyl)acetamide (1 g, 1.86 mM) in 50 ml of dichloro-
methane was cooled to 0 °C and 10-fold excess of BBr3 was added.
The reaction mixture was stirred for 3 h at room temp, cooled to
0 °C and methanol was added dropwise. Organic solvents were
evaporated under reduced pressure and residue was purified using
column chromatography on silica gel using mixture of hexane–
ethyl acetate (1:3) as an eluent providing 700 mg (72% yield)of
pure product. 1H NMR (400 MHz, CDCl3) 7.76 (d, J = 7.8 Hz, 1H);
7.16–7.30 (m, 8H); 7.02–7.08 (m, 1H); 6.66–6.95 (m, 3H); 5.82–
5.89 (m, 2H); 4.87 (q, J = 6.8 Hz, 1H); 3.63–3.96 (m, 4H); 0.97
(two d, J = 6.6 Hz, 6H). MS (FAB) [M+H]+ = 524.
4.4.10. 2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-5-phenyl-
2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-isopropyl-N-
phenylacetamide (Compound 14)
This compound was prepared as compound 11 using N1-isopro-
pyl-N1-phenylglycinamide
instead
of
N1-isopropyl-N1-(4-
methoxyphenyl)glycinamide. 1H NMR (400 MHz, CDCl3): 7.82 (d,
J = 9 Hz, 1H); 7.09–7.47 (m, 13H); 6.03 (d, J = 6.2, 1H); 5.98 (d,
J = 6.2 Hz, 1H); 4.98 (q, J = 6.8 Hz, 1H); 4.26 (dd, J = 7.8 Hz,
J = 2.0 Hz, 1H); 3.97 (d, J = 16.5 Hz, 1H); 3.88 (d, J = 16.5, 1H);
3.78–3.86 (m, 1H); 3.63 (dd, J = 16.3 Hz, J = 5.5 Hz, 1H); 1.05–1.92
(m, 6H). MS (FAB) [M+H]+ = 508.
4.4.16. 2-[6-(1H-Indazol-3-ylmethyl)-5,7-dioxo-4-(3-pyridinyl)-
4,5,6,7-tetrahydro-1H-1,4-diazepin-1-yl]-N-(1-methylethyl)-N-
[4-(methyloxy)phenyl]acetamide (Compound 20)
4.4.11. 2-[2,4-Dioxo-3-(6-fluoro-1H-indazol-3-ylmethylene)-5-
phenyl-2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-isopropyl-
N-phenylacetamide (Compound 15)
Thiscompound was preparedascompound 11 using N1-isopropyl-
This compound was prepared as compound 11 using H-[2,2-
bis(ethyloxy)ethyl]-3-pyridinamine instead of 2-(N-anilino)acetal-
dehyde diethyl acetal. 1H NMR (400 MHz, CDCl3) 10.40 (br s, 1H),
8.61 (m, 1H), 8.53 (m, 1H), 7.82 (m, 1H), 7.751 (m, 1H), 7.44–
7.32 (m, 3H), 7.24–7.12 (m, 3H), 7.02–6.96 (m, 2H), 6.14 (d,
J = 6.3 Hz,1H), 5.98 (d, J = 6.3 Hz,1H), 5.00 (sept., J = 6.3 Hz, 1H),
4.38–4.32 (m, 1H), 4.00 (d, J = 8.2 Hz, 1H), 3.87 (s, 3H), 3.92–3.82
(m, 1H), 3.66–3.56 (m, 1H), 1.10 (d, J = 6.3 Hz, 6H), MS (FAB)
[M+H]+ = 539.
1
N-phenylglycinamideinsteadofN1-isopropyl-N1-(4-methoxyphenyl)
glycinamide and tert-butyl 3-(bromomethyl)-6-fluoro-1H-inda-
zole-1-carboxylate instead of of tert-butyl 3-(bromomethylene)-
1H-indazole-1-carboxylate. 1H NMR (300 MHz, CDCl3): 7.71 (dd,
J = 8.8 Hz, J = 5.3 Hz, 1H); 7.18–7.50 (m, 10H); 6.98 (dd, J = 9.3 Hz,
J = 1.9 Hz, 1H); 6.87 (td, J = 9.1 Hz, J = 2.0 Hz, 1H); 6.05 (d,
J = 6.6 Hz, 1H); 5.95 (d, J = 6.6 Hz, 1H); 5.01 (q, J = 6.7 Hz, 1H);
3.74–4.28 (m, 5H); 3.46–3.56 (m, 1H); 1.09 (m, 6H). (MS (FAB)
[M+H]+ = 526.
4.4.17. 2-[6-(6-Fluoro-1H-indazol-3-ylmethylene)-5,7-dioxo-4-
(3-pyridinyl)-4,5,6,7-tetrahydro-1H-1,4-diazepin-1-yl]-N-(1-
methylethyl)-N-[4-(methyloxy)phenyl]acetamide (Compound
22)
4.4.12. 2-[2,4-Dioxo-3-(6-fluoro-1H-indazol-3-ylmethylene)-5-
phenyl-2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-isopropyl-
N-(4-methoxyphenyl)acetamide (Compound 16)
This compound was prepared as compound 11 using N-[2,2-
bis(ethyloxy)ethyl]-3-pyridinamine instead of 2-(N-anilino)acetal-
dehyde diethyl acetal and tert-butyl 3-(bromomethyl)-6-fluoro-
This compound was prepared as compound 11 tert-butyl 3-(bro-
momethyl)-6-fluoro-1H-indazole-1-carboxylate instead of tert-bu-
tyl 3-(bromomethylene)-1H-indazole-1-carboxylate. 1H NMR

J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
1831
1H-indazole-1-carboxylate instead of tert-butyl 3-(bromomethyl-
ene)-1H-indazole-1-carboxylate. 1H NMR (400 MHz, CDCl3) 10.40
(br s, 1H), 8.61 (m, 1H), 8.53 (m, 1H), 7.82 (m, 1H), 7.751 (m,1H),
7.30–7.26 (m, 1H), 7.24–7.12 (m, 3H), 7.02–6.96 (m,3H), 6.14 (d,
J = 6.3 Hz,1H), 5.98 (d, J = 6.3 Hz,1H), 5.00 (sept., J = 6.3 Hz, 1H),
4.38–4.32 (m, 1H), 4.00 (d, J = 8.2 Hz, 1H), 3.87 (s, 3H), 3.92–3.82
(m, 1H), 3.66–3.56 (m, 1H), 1.10 (d, J = 6.3 Hz, 6H), MS (FAB)
[M+H]+ = 557.
1H), 7.00–6.90 (m, 4H), 5.98 (dd, J = 6.3 Hz, 14.7 Hz, 2H), 4.99–4.88
(m, 3H), 4.17–4.06 (m, 2H), 3.91–3.82 (m, 2H), 3.86 (s, 3H), 3.75–
3.65 (M, 2H), 1.07 (d, J = 6.7 Hz, 3H), 1.06 (d, J = 6.7 Hz, 3H). MS
(ES+) [M+H]+ = 558.
4.4.23. 2-[6-(1H-Indazol-3-ylmethyl)-5,7-dioxo-4-
(phenylmethyl)-4,5,6,7-tetrahydro-1H-1,4-diazepin-1-yl]-N-(1-
methylethyl)-N-[4-(methyloxy)phenyl]acetamide (Compound
28)
4.4.18. 2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-3-methoxy-
5-phenyl-2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-(4-
fluorophenyl) N-isopropylacetamide (Compound 23)
This compound was prepared as compound 11 using N1-isopro-
pyl-N’-(4-fluorophenyl)glycinamide instead of N1-isopropyl-N1-(4-
methoxyphenyl)glycinamide and methyl 3-chloro-2-(methyloxy)-
3-oxopropanoate instead of methyl malonyl chloride. 1H NMR
(400 MHz, CDCl3) 7.96 (d, J = 8.4 Hz, 1H); 7.49–7.58 (m, 2H);
7.32–7.36 (m, 2H); 7.15–7.28 (m, 8H); 5.95 (d, J = 6.6 Hz, 1H);
5.92 (d, J = 6.6 Hz, 1H); 4.98 (q, J = 7.2 Hz, 1H); 4.04–4.21 (m,
3H); 3.74 (d, J = 6.6 Hz, 1H); 3.47 (s, 3H); 1.07 (m, 6H) MS (FAB)
[M+H]+ = 556.
This compound was prepared as compound 11 using 2,2-
bis(ethyloxy)-N-(phenylmethyl)ethanamine instead of 2-(N-anili-
no)acetaldehyde diethyl acetal. 1H NMR (300 MHz, CDCl3) 7.91
(d, J = 8.1 Hz, 1H), 7.54–7.41 (m, 2H), 7.35–7.04 (m, 9H), 6.99–
6.92 (m, 3H), 5.93 (d, J = 6.5 Hz, 1H), 5.86 (d, J = 6.5 Hz, 1H),
5.02–4.90 (m, 1H), 4.78 (br s, 2H), 4.23–4.14 (m, 1H), 4.05 (s,
0.5H), 4.00 (s, 0.5H), 3.91–3.78 (m, 3H), 3.86 (s, 3H), 3.74 (m,
1H), 1.09–1.04 (m, 6H). MS (ES+) [M+H]+ = 552.
4.4.24. 2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-5-phenyl-
2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-isopropyl-N-(2-
methyl-4-trifluoromethoxy)phenyl)acetamide (Compound 29)
This compound was prepared as compound 11 using N1-isopro-
pyl-N1-(4-trifluoromethoxyphenyl)glycinamide instead of N1-iso-
propyl-N1-(4-methoxyphenyl)glycinamide. 1H NMR (400 MHz,
CD3OD) 7.91 (1H, d, J = 8.06 Hz), 7.35 (10H, m), 7.21 (1H, m),
7.09 (1H, dd, J = 7.51 Hz), 6.11 (2H, m), 4.69 (1H, qq, J = 6.59 Hz),
4.22 (1H, m), 4.07 (2H, m), 3.71 (2H, m), 3.56 (1H, m), 2.39 (3H,
d, J = 4.03 Hz), 1.99 (3H, s), 1.22 (6H, m). MS (EI) [M+H]+ = 606.
4.4.19. 2-[4-Cyclohexyl-5,7-dioxo-6-(phenylmethyl)-4,5,6,7-
tetrahydro-1H-1,4-diazepin-1-yl]-N-(1-methylethyl)-N-[4-
(methyloxy)phenyl]acetamide (Compound 24)
Compound 24 was prepared by a previously published solid
supported synthesis.17 1H NMR (300 MHz, CDCl3) 7.32–7.08 (m,
9H), 6.99 (s, 1H), 6.96 (s, 1H), 5.95 (d, J = 6.5 Hz, 1H), 5.90 (d,
J = 6.5 Hz, 1H), 4.97 (quint, J = 6.7 Hz, 1H), 4.40 (m, 1H), 4.05 (d,
J = 16.5 Hz, 1H), 3.87 (s, 3H), 3.70 (d, J = 16.5 Hz, 1H), 3.53–3.30
(m, 3H), 1.90–1.60 (m, 7H), 1.54–1.20 (m, 5H), 1.09 (d, J = 6.7 Hz,
3H), 1.08 (d, J = 6.7 Hz, 3H). MS (ES+) [M+H]+ = 504.
4.4.25. 2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-3-methoxy-
5-phenyl-2,3,4,5-tetrahydro-1H-1,5-diazepin-1-yl]-N-(4-
methoxyphenyl) N-isopropylacetamide (Compound 30)
This compound was prepared as compound 11 using methyl 3-
chloro-2-(methyloxy)-3-oxopropanoate instead of methyl malonyl
chloride. 1H NMR (400 MHz, CDCl3) 7.96 (d, J = 8.4 Hz, 1H); 7.49–
7.08 (m, 8H); 6.96–6.76 (m, 4H); 5.96 (d, J = 6.6 Hz, 1H); 5.89 (d,
J = 6.6 Hz, 1H); 4.98 (q, J = 7.2 Hz, 1H); 4.04–4.21 (m, 3H); 3.74
(d, J = 6.6 Hz, 1H); 3.87 (s, 3H), 3.47 (s, 3H); 1.07 (m, 6H) MS
(FAB) [M+H]+ = 568.
4.4.20. 2-[6-(1H-Indazol-3-ylmethyl)-5,7-dioxo-4-phenyl-
4,5,6,7-tetrahydro-1H-1,4-diazepin-1-yl]-N-(1-methylethyl)-N-
[4-(4-morpholinyl)phenyl]acetamide (Compound 25)
This compound was prepared as compound 11 using N1-(1-
methylethyl)-N1-[4-(4-morpholinyl)phenyl]glycinamide instead
of N1-isopropyl-N1-(4-methoxyphenyl)glycinamide. 1H NMR
(400 MHz, CDCl3) 7.71 (d, J = 8.0 Hz, 1H); 7.35–7.19 (m, 6H);
7.12–7.01 (m, 3H); 6.91–6.83 (m, 3H); 6.10 (d, J = 7.4 Hz, 1H);
5.88 (d, J = 7.4 Hz, 10H); 4.96 (q, J = 7.2 Hz, 1H); 4.27–4.22 (m,
1H); 4.03 (d, J = 16.4 Hz, 1H); 3.88–3.75 (m, 6H); 3.5 (dd,
J = 16.4 Hz, J = 5.1 Hz, 1H); 3.16 (m, 4H); 1.04 (m, 6H).
4.4.26. Diphenyl {[6-(1H-indazol-3-ylmethyl)-5,7-dioxo-4-
phenyl-4,5,6,7-tetrahydro-1H-1,4-diazepin-1-yl]methyl}
phosphonate (Compound 31)
Under nitrogen atmosphere and anhydrous conditions, a mix-
ture of 6.12 g (40.5 mmol) of benzyl carbamate, 5.14 g (50.3 mmol)
of acetic anhydride, and 1.22 g (40.6 mmol) of paraformaldehyde
in 4 mL of acetic acid was heated at 65 °C for 3 h. The resulting
solution was treated with 12.7 g (40.8 mmol) of triphenyl phos-
phite and heated at 115–120 °C for 2 h. The mixture was concd un-
der high vacuum then a portion of the material was taken up in a
small volume of diethyl ether and chilled overnight to give precip-
itate that was isolated by filtration, washed well with diethyl ether,
and dried under high vacuum to give 2.44 g of diphenyl [({[(phen-
4.4.21. 2-[4-Cyclohexyl-6-(1H-indazol-3-ylmethyl)-5,7-dioxo-
4,5,6,7-tetrahydro-1H-1,4-diazepin-1-yl]-N-(1-methylethyl)-N-
[4-(methyloxy)phenyl]acetamide trifluoroacetate (Compound
26)
This compound was prepared as compound 24 using 1,1-
dimethylethyl 3-(bromomethyl)-1H-indazole-1-carboxylate in-
stead of benzyl bromide. 1H NMR (300 MHz, CDCl3) 7.87 (d,
J = 7.5 Hz, 1H), 7.48 (m, 2H), 7.20 (m, 1H), 7.08 (m, 2H), 6.91 (m,
2H), 4.92 (quint, J = 6.7 Hz, 1H), 4.35 (m, 1H), 4.04–3.91 (m, 2H),
3.81 (s, 3H), 3.79–3.66 (m, 3H), 1.84–1.58 (m, 7H), 1.51–1.17 (m,
5H), 1.02 (d, J = 6.6 Hz, 3H), 1.00 (d, J = 6.8 Hz, 3H). MS (ES+)
[M+H]+ = 544.
ylmethyl)oxy]carbonyl}amino)methyl]phosphonate as
a bright
white solid. Of this sample, 88 mg (0.22 mmol) was taken up in
glacial acetic acid and treated with 1 mL of 30% HBr/acetic acid
and stirred for 2 h at room temperature. The solution was concen-
trated in vacuo and the resulting sample in a few drops of acetic
acid was added to diethyl ether to induce precipitation. After
standing overnight, the ethereal supernatant was decanted and
the solids were washed thoroughly with diethyl ether under nitro-
gen atmosphere. The resulting solids were dried under high vac-
uum to give diphenyl (aminomethyl)phosphonate hydrobromide
as a finely divided light tan powder that was immediately utilized
in the subsequent reaction. See note in following paragraph.
4.4.22. 2-[6-(1H-Indazol-3-ylmethyl)-5,7-dioxo-4-(2-thienyl
methyl)-4,5,6,7-tetrahydro-1H-1,4-diazepin-1-yl]-N-(1-
methylethyl)-N-[4-(methyloxy)phenyl]acetamide (Compound
27)
This compound was prepared as compound 11 using 2,2-
bis(ethyloxy)-N-(2-thienylmethyl)ethanamine instead of 2-(N-ani-
lino)acetaldehyde diethyl acetal. 1H NMR (300 MHz, CDCl3) 7.90 (d,
J = 8.1 Hz, 1H), 7.51–7.38 (m, 2H), 7.24–7.14 (m, 3H), 7.09–7.02 (m,

1832
J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
A solution of 108 mg (0.20 mmol) of methyl 3-[[2,2-bis(ethyl-
J = 8.4 Hz, 1H); 7.49–7.08 (m, 8H); 6.96–6.83 (m, 2H); 6.05–5.93
(m, 2H); 4.98–4.88 (m, 1H); 4.32(q, J = 7.0 Hz 2H), 4.20–4.15 (m,
1H); 3.98–3.82 (m, 4H),3.82 (s, 3H); 3.35–3.58 (m, 1H); 1.43 (t,
J = 7.0 Hz, 3H); 1.04 (d, J = 6.3 Hz, 6H) MS (FAB) [M+H]+ = 566.
oxy)ethyl](phenyl)amino]-2-(1H-indazol-3-ylmethyl)-3-oxopro-
panoate, prepared in an the same way as Compound 9, in THF
(5 mL) and water (2 mL) at 0 °C was treated with 0.205 mL of
1.00 M NaOH. The solution was stirred at room temperature for
4 h then concd in vacuo to remove THF. The aqueous suspension
was lyophillized to give white solid powder which was taken up
in anhydrous DMF (4 mL) and treated with 29 mg (0.21 mmol) of
HOBT, 61 mg (0.21 mmol) of EDCI, and 26 mg (0.20 mmol) DIEA.
The solution was stirred for 30 min at room temperature then trea-
ted with 0.22 mmol of diphenyl (aminomethyl)phosphonate
hydrobromide [Can omit above prep and note here ‘prepared as
previously reported. . .Ref: Oleksyszyn, J.; Subotkowska, L. Synthe-
sis Communications, vol. 11, p 906 (1980)] in 1.5 mL of DMF. The
resulting solution was stirred at room temperature overnight then
concd in vacuo, applied to silica gel, and purified by column chro-
matography eluting with 50–60% EtOAc/hexane to give 82 mg
(0.106 mmol) of intermediate diphenyl ({[3-[[2,2-bis(ethyl-
oxy)ethyl](phenyl)amino]-2-(1H-indazol-3-ylmethyl)-3-oxopropa-
noyl]amino}methyl)phosphonate. This intermediate was taken up
in dry toluene and treated with anhydrous toluenesulfonic acid
(0.12 mmol) in toluene. A small proportion of the toluene was
evaporated to ensure dryness then the solution was heated at
70 °C for 1 h. The reaction mixture was applied to a 2 g silica gel
cartridge and products were eluted with 80% EtOAc/hexane to give
Boc protected intermediate and 4 mg of the title compound. 1H
NMR (300 MHz, CDCl3) 8.15 (d, J = 8.7 Hz, 1H), 7.85 (br d,
J = 8.0 Hz, 2H), 7.71 (m, 2H), 7.35–6.98 (m, 16H), 6.12 (dd, J = 39,
J = 6.3, 2H), 4.57 (m, 1H), 3.98 (m, 2H). MS (ES+) [M+H]+ = 579.
4.4.29. Phenyl hydrogen {[6-(1H-indazol-3-ylmethyl)-5,7-
dioxo-4-phenyl-4,5,6,7-tetrahydro-1H-1,4-diazepin-1-
yl]methyl}phosphonate (Compound 34)
14 mg (0.021 mmol) of 1,1-dimethylethyl 3-[(1-{[hydroxy(phe-
nyloxy)phosphoryl]methyl}-5,7-dioxo-4-phenyl-4,5,6,7-tetrahydro-
1H-1,4-diazepin-6-yl)methyl]-1H-indazole-1-carboxylate, prepared
as an intermediate of comopound 31, in 1 mL of dichloromethane
at 0 °C was treated with 0.5 mL of trifluoroacetic acid. The solution
was stirred for 3 h then concd in vacuo. The residue was twice
taken up in dichloromethane and conc. in vacuo. The sample was
taken up in 1,4-dioxane and treated with 0.2 mL of 1.00 M NaOH.
The resulting solution was stirred at room temperature overnight.
The reaction was treated with excess acetic acid and conc. in vacuo
to give crystalline solid which was purified by preparative HPLC on
RP-C8 eluting with acetonitrile/water (0.1% TFA). Fractions of inter-
est were lyophilized to give 3 mg of the TFA salt of the title com-
pound as an off-white solid. 1H NMR (400 MHz, CDCl3+D2O) 7.82
(m, 1H), 7.44–6.99 (m, 15H), 6.58 (br s, 1H), 5.96 (br s, 1H), 4.07
(m, 1H), 3.80–3.55 (m, 2H). MS (ES+) [M+H]+ = 503.
4.4.30. 2-{6-[(6-Fluoro-1H-indazol-3-yl)methyl]-4-methyl-5,7-
dioxo-4,5,6,7-tetrahydro-1H-1,4-diazepin-1-yl}-N-(4-
fluorophenyl)-N-(1-methylethyl)acetamide (Compound 35)
This compound was prepared as compound 11 using 2,2-
bis(ethyloxy)-N-methylethanamine instead of 2-(N-anilino)acetal-
dehyde diethyl acetal. 1H NMR (400 MHz, CDCl3) 7.78(d,d, 1H);
7.249–7.08 (m, 4H); 7.02–6.98 (m, 1H); -6.93–6.86 (m, 1H); 5.91
(d, 1H); 5.87 (d, 1H); 4.98–4.88 (m, 1H); 4.03–3.92 (m, 2H);
3.78–3.68 (m, 2H),3.3.63–3.57 (m, 1H); 3.12 (s, 3H); 1.04 (d,
J = 6.3 Hz, 6H) MS (FAB) [M+H]+ = 582.
4.4.27. N-(1-methylethyl)-2-{6-[(1-methyl-1H-indazol-3-
yl)methyl]-5,7-dioxo-4-phenyl-4,5,6,7-tetrahydro-1H-1,4-
diazepin-1-yl}-N-[4-(methyloxy)phenyl]acetamide (Compound
32)
2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-5-phenyl-2,3,4,5-tet-
rahydro-1H-1,5-diazepin-1-yl]-N-isopropyl-N-(4-methoxyphenyl)-
acetamide (64 mg; 0.1 mmol) was dissolved in DMF and cooled to
°C. 0.6 M solution of Na(NSiMe2)3 was added dropwise, and mix-
ture was stirred 30 min at 0 °C, and iodomethane (14 mg) was
added in DMF. Reaction mixture was stirred for 2 h at ethyl acetate
and washed with 1 M NaHSO4 and satd sodium bicarbonate. The
organic layer was dried and solvent removed under reduced pres-
sure. Crude product was purified by HPLC on C-8 RP acetonitrile/
water (0.1% TFA) to provide 60 mg of desired material as a white
solid after lyophilization. 1H NMR (400 MHz, CDCl3) 7.86 (d,
J = 8.4 Hz, 1H); 7.49–7.08 (m, 8H); 6.96–6.83 (m, 2H); 6.05–5.93
(m, 2H); 4.98–4.88 (m, 1H); 4.20–4.15 (m, 1H); 3.96 (s, 3H), 3.92
(m, 4H), 3.82 (s, 3H); 1.04 (d, J = 6.3 Hz, 6H) MS (FAB)
[M+H]+ = 552.
Racemic compounds were separated on a Prochrom Preparative
Supercritical Fluid Chromatograph Super C20 as summarized
below.
4.4.30.1. Resolution of Compound 11.
Anal. Column Chiral-
cel OD (250 ꢂ 4.6 mm).
70% CO2/30% MeOH (10% Chloroform), 2 ml/min, 40C, 210 Bars.
Enantiomer #1: 3.0 min [Compound 11-(S)].
Enantiomer #2: 5.5 min [Compound 11-(R)].
Prep. Column Chiralcel OD,(250 ꢂ 20 mm).
50 g/min CO2, 19.3 ml/min MeOH (10% Chloroform), 40C, 210
Bars.
Enantiomer #1: 6.0 min [Compound 11-(S)].
Enantiomer #2: 13.1 min [Compound 11-(R)].
4.4.28. 2-{6-[(1-Ethyl-1H-indazol-3-yl)methyl]-5,7-dioxo-4-
phenyl-4,5,6,7-tetrahydro-1H-1,4-diazepin-1-yl}-N-(1-
methylethyl)-N-[4-(methyloxy)phenyl]acetamide (Compound
33)
4.4.30.2. Resolution of Compound 14.
cel OJ (250 ꢂ 4.6 mm).
Anal. Column Chiral-
88% CO2/12% EtOH, 2 ml/min, 40C, 210 Bars, 13.9 and 18.5 min.
Enantiomer #1: 13.9 min [Compound 14-(S)].
Enantiomer #2: 18.5 min [Compound 14-(R)].
Prep. Column Chiralcel OJ (250 ꢂ 20 mm).
45 g/min CO2, 9.9 ml/min EtOH, 40C, 210 Bars.
Enantiomer #1: 13.0 min [Compound 14-(S)].
Enantiomer #2: 17.8 min [Compound 14-(R)].
2-[2,4-Dioxo-3-(1H-indazol-3-ylmethylene)-5-phenyl-2,3,4,5-tet-
rahydro-1H-1,5-diazepin-1-yl]-N-isopropyl-N-(4-methoxyphenyl)ace-
tamide 64 mg (0.1 mM) was dissolved in DMF and cooled to °C.
0.6 M solution of Na(NSiMe2)3 was added dropwise and mixture
was stirred 30 min at 0 °C and iodoethane (16 mg) was added in
DMF. Reaction mixture was stirred for 2 h at rt and solvent re-
moved under reduced pressure. Residue was dissolved in ethyl
acetate and washed with 1 M NaHSO4 and satd sodium bicarbon-
ate. Organic layer was dried and solvent removed under reduced
pressure. Crude product was purified by HPLC on C-8 RP using ace-
tonitrile/water(0.1% TFA) providing 60 mg of desired material as a
white solid after lyophilization. 1H NMR (400 MHz, CDCl3) 7.86 (d,
4.4.30.3. Resolution of Compound 15.
Anal. Column Chiral-
cel OJ (250 ꢂ 4.6 mm).
88% CO2/12% EtOH, 2 ml/min, 40C, 210 Bars.
Enantiomer #1: 10.7 min [Compound 15-(S)].
Enantiomer #2: 14.0 min [Compound 15-(R)].
Prep. Column Chiralcel OJ (250 ꢂ 20 mm).

J. R. Szewczyk et al. / Bioorg. Med. Chem. 18 (2010) 1822–1833
1833
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Rep. Med. Chem. 2003, 38, 31.
8. Aquino, C. J.; Armour, D. R.; Berman, J. M.; Birkemo, L. S.; Carr, R. A. E.; Croom, D.
K.; Dezube, M.; Dougherty, R. W., Jr.; Ervin, G. N., et al J. Med. Chem. 1996, 39,
562.
45 g/min CO2, 9.9 ml/min EtOH, 40C, 210 Bars.
Enantiomer #1: 10.5 min [Compound 15-(S)].
Enantiomer #2: 14.5 min [Compound 15-(R)].
9. Henke, B. R.; Aquino, C. J.; Birkemo, L. S.; Croom, D. K.; Dougherty, R. W., Jr.;
Ervin, G. N.; Grizzle, M. K.; Hirst, G. C.; James, M. l. K.; Johnson, M. F.; Queen, K.
L.; Sherrill, R. G.; Sugg, E. h. E.; Suh, E. M.; Szewczyk, J. W.; Unwalla, R. J.;
Yingling, J.; Willson, T. M. J. Med. Chem. 1997, 40, 2706.
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12. Guo, C.; Reich, S.; Showalter, R.; Villafranca, E.; Dong, L. Tetrahedron Lett. 2000,
41, 5307.
4.4.30.4. Resolution of Compound 13.
cel OD (250 ꢂ 4.6 mm), 7.
Anal. Column Chiral-
0% CO2/30% MeOH (10% Chloroform), 2 ml/min, 40C, 210 Bars.
Enantiomer #1: 8.2 min [Compound 13-(S)].
Enantiomer #2: 14.4 min [Compound 13-(R)].
Prep. Column Chiralcel OD (250 ꢂ 20 mm).
45 g/min CO2, 16 ml/min MeOH (10% Chloroform), 40C, 210
Bars.
13. (a) McCann, J. L.; Rauk, A.; Wieser, H.
A conformational study of
(1S,2S,5S)-(+)-menthol using vibrational circular dichroism spectroscopy
Can. J. Chem. 1998, 76, 274–283; (b) Freedman, T. B.; Cao, X.; Dukor, R.
K.; Nafie, L. A. Absolute configuration determination of chiral molecules
in the solution state using vibrational circular dichroism Chirality 2003,
15, 743–758.
Enantiomer #1: 8.5 min [Compound 13-(S)].
Enantiomer #2: 11.5 min [Compound 113-(R)].
4.4.30.5. Resolution of 19.
4.6 mm).
Anal. Column Chiralpak AS (250 ꢂ
14. (a) Freedman, T. B.; Cao, X.; Phillips, L. M.; Cheng, P. T. W.; Dalterio, R.; Shu, Y.;
Zhang, H.; Zhao, N.; Shukia, R. B.; Tymiak, A.; Gozo, S. K.; Nafie, L. A.;
Gougoutas, J. Z. Determination of the absolute configuration and solution
conformation of a novel disubstituted pyrrolidine acid a by vibrational circular
dichroism Chirality 2006, 18, 746–753; (b) Minick, D. J.; Copley, R. C.; Szewczyk,
J. R.; Rutkowske, R. D.; Miller, L. A. Chirality 2007, 19, 731.
15. Goetz, A. S.; Andrews, J. L.; Littleton, T. R. Ignar DM development of a facile
method for high throughput screening with reporter gene assays J. Biomol.
Screening 2000, 5, 377.
16. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M.A.;
Cheeseman, J.R.; Montgomery, Jr. J.A.; Vreven, T.; Kudin, K.N.; Burant, J.C.;
Millam, J.M.; Iyengar, S.S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.;
Scalmani, G.; Rega, N.; Petersson, G.A.; Nakatsuji, H.; Hada, M.; Ehara, M.;
Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao,
O.; Nakai, H.; Klene, M.; Li, X.; Knox, J.E.; Hratchian, H.P.; Cross, J.B.; Bakken, V.;
Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R.E.; Yazyev, O.; Austin, A.J.;
Cammi, R.; Pomelli, C.; Ochterski, J.W.; Ayala, P.Y.; Morokuma, K.; Voth, G.A.;
Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.;
Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.;
Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.;
Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.;
Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe,
M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; Pople, J. A.
GAUSSIAN 03, Revision C.02, Gaussian, Inc.: Wallingford CT, 2004.
85% CO2/15% EtOH, 2 ml/min, 40C, 210 Bars.
Enantiomer #1: 18.4 min (Compound 19-a).
Enantiomer #2: 27.1 min (Compound 19-b).
Prep. Column Chiralcel AS (250 ꢂ 20 mm).
42 g/min CO2, 8 ml/min EtOH, 40C, 210 Bars.
Enantiomer #1: 12.3 min (Compound 19-a).
Enantiomer #2: 17.6 min (Compound 19-b).
References and notes
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Johansson, B. t.; Holm, M.; Botoros, M.; Karlen, A.; Pettersson, A.; Nyberg, F.;
Faendriks, L.; Gallo-Payet, N.; Hallberg, A.; Alterman, M. J. Med. Chem. 2004, 47,
5995.
2. Ye, Z.; Gao, Y.; Bakshi, R. K.; Chen, M. H.; Rohrer, S. P.; Feighner, S. D.; Pong, S. S.;
Howard, A. D.; Blake, A.; Birzin, E. T.; Locco, L.; Parmar, R. M.; Chan, W. W.;
Schaeffer, J. M.; Smith, R. G.; Patchett, A. A.; Nargund, R. P. Bioorg. Med. Chem.
Lett. 2000, 10, 5.
3. Nargund, R. P.; Barakat, K. H.; Cheng, K.; Chan, W. W.-S.; Butler, B. R.; Smith, R.
G.; Patchett, A. A. P. Bioorg. Med. Chem. Lett. 1996, 6, 1265.
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L.; Dodge, J. A. P. Bioorg. Med. Chem. Lett. 2004, 14, 5873.
17. Laudeman, C. P.; Szewczyk, J. R.; Andrews, J. L.; Barvian, K. K.; Carpenter, A. J.;
Drewry, D. H.; Fernandez, E. P.; Gerritz, S.; Ignar, D. M.; Minick, D. J.; Salovich, J.
M.; Speake, J. D. A Facile Solid Phase Synthesis of Diazepinediones; A Novel
Class of Compounds with MC4R Activity, 30th National Medicinal Chemistry
Symposium, 2006, Poster 123.
5. Szewczyk, J. R.; Laudeman, C. Curr. Top. Med. Chem. 2003, 3, 837.
6. Bednarek, M. A.; Fong, T. M. Expert Opin. Ther. Patents 2004, 14, 327.