Discovery and optimization of adamantane carboxylic acid derivatives as potent diacylglycerol acyltransferase 1 inhibitors for the potential treatment of obesity and diabetes

Article abstract of DOI:10.1016/j.ejmech.2015.06.043

Abstract We have developed a series of adamantane carboxylic acid derivatives exhibiting potent diacylglycerol acyltransferase 1 (DGAT1) inhibitory activities. Optimization of the series led to the discovery of E-adamantane carboxylic acid compound 43c, which showed excellent in vitro activity with an IC₅₀ value of 5 nM against human and mouse DGAT1, also good druggability as well as microsomal stability and safety profiles such as hERG, CYP and cytotoxicity. Compound 43c significantly reduced plasma triglyceride levels in vivo (in rodents and zebrafish) and also showed bodyweight gain reduction and glucose area under curve (AUC) lowering efficacy in diet-induced obesity (DIO) mice.

Full text of DOI:10.1016/j.ejmech.2015.06.043

Accepted Manuscript
Discovery and Optimization of Adamantane Carboxylic Acid Derivatives as Potent
Diacylglycerol Acyltransferase 1 Inhibitors for the Potential Treatment of Obesity and
Diabetes
Suvarna H. Pagire, Haushabhau S. Pagire, Gwi Bin Lee, Seo-Jung Han, Hyun Jung
Kwak, Ji Young Kim, Ki Young Kim, Sang Dal Rhee, Jeong Im Ryu, Jin Sook Song,
Myung Ae Bae, Mi-jin Park, Dooseop Kim, Duck Hyung Lee, Jin Hee Ahn
PII:
S0223-5234(15)30118-5
10.1016/j.ejmech.2015.06.043
EJMECH 7970
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 23 February 2015
Revised Date: 6 June 2015
Accepted Date: 22 June 2015
Please cite this article as: S.H Pagire, H.S. Pagire, G.B. Lee, S.-J. Han, H.J. Kwak, J.Y. Kim, K.Y.
Kim, S.D. Rhee, J.I. Ryu, J.S. Song, M.A. Bae, M.-j. Park, D. Kim, D.H. Lee, J.H. Ahn, Discovery and
Optimization of Adamantane Carboxylic Acid Derivatives as Potent Diacylglycerol Acyltransferase 1
Inhibitors for the Potential Treatment of Obesity and Diabetes, European Journal of Medicinal Chemistry
(2015), doi: 10.1016/j.ejmech.2015.06.043.
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ACCEPTED MANUSCRIPT
TABLE OF CONTENTS GRAPHIC
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ACCEPTED MANUSCRIPT
Discovery and Optimization of Adamantane Carboxylic Acid Derivatives as
Potent Diacylglycerol Acyltransferase 1 Inhibitors for the Potential Treatment
of Obesity and Diabetes
†
, ‡,⊥
†, ‡,⊥
†
†
†
†
Suvarna H Pagire,
Haushabhau S. Pagire,
Gwi Bin Lee, Seo-Jung Han, Hyun Jung Kwak,
†
†
†
†
†
Ji Young Kim, Ki Young Kim, Sang Dal Rhee, Jeong Im Ryu, Jin Sook Song, Myung Ae Bae,
§
§
∥
†, ‡,
Mi-jin Park, Dooseop Kim, Duck Hyung Lee, Jin Hee Ahn
*
†
Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, 305-600, Korea,
Department of Medicinal and Pharmaceutical Chemistry, University of Science and Technology, 305-
33, Korea,
‡
3
§
Handok Pharmaceuticals Co., Ltd. Seoul 135-755, Republic of Korea,
∥
Department of Chemistry, Sogang University, Seoul 121-742, Republic of Korea.
1
. INTRODUCTION
Inhibitors of diacylglycerol acyltransferase 1 (DGAT1) have come to the fore in recent years as
potential therapies for obesity, diabetes and other elements of metabolic syndrome [1] Acyl CoA:
diacylglycerol acyltransferase (DGAT) enzymes catalyze the final and the only committed step
in triglyceride synthesis; the joining of 1, 2-diacylglycerol and fatty acyl CoA at the endoplasmic
reticulum [2, 3]. Two members of this enzyme family have been reported; DGAT1 and DGAT2.
Although both reported enzymes catalyze the formation of triglycerides (TG) from
diacylglycerol and fatty acyl CoA and share limited homology. Mice lacking the DGAT1 gene
were shown to be viable and resistant to the effects of diet-induced obesity (DIO) and hepatic
steatosis when fed a high-fat diet. Additionally, these animals were reported to have an increased
sensitivity to both insulin and leptin, decreased levels of tissue triglycerides, and increased
−
/−
energy expenditure. Further studies demonstrated that DGAT1 mice had dramatically reduced
levels of intestinal triglyceride synthesis and chylomicron secretion following an oral lipid

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challenge [4-6]. These studies have spurred research efforts to determine whether selective small
molecule inhibitors of DGAT1 can produce the same improved metabolic profile observed in the
-/-
DGAT1 animals.
A number of small molecule inhibitors [7] of DGAT1 have been reported and the progress of
some of these compounds into clinical development supports the potential for their therapeutic
use (Fig. 1).
The DGAT1 inhibitor discovered by Novartis, pradigastat (LCQ908) is the most advanced
clinical candidate and is currently being evaluated in phase II and phase III studies [8a]. Novartis
has recently disclosed that pradigastat lowered the fasting plasma TG level in patients with
familial chylomicronemia syndrome [8b,c]. Also, AstraZeneca and Pfizer candidates [9] have
been advanced into clinical trials and showed markedly reduced postprandial TG excursion with
gastrointestinal side effects.
Fig. 1.
In an attempt to identify additional pharmacophores that could serve as inhibitors of DGAT1, we
conducted a high-throughput screen (HTS) against DGAT1. Adamantane containing compound
7
(Fig. 2) was identified as a hit with IC values of 539 nM and 2651 nM against human and
50
mouse DGAT1, respectively.
Fig. 2.

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The adamantane group also exists in several other drugs (Fig. 3). The first adamantane derivative
used as a drug was amantadine in 1967, which initially used as an antiviral drug against various
strains of flu [10] and then to treat parkinson’s disease (adapalene, dopamantine, memantine,
rimantadine and tromantadine) as well as dipeptidyl peptidase-4 (DPP-4) inhibitors for diabetes
(saxagliptin, and vildagliptin) [11, 12]. Also, polymers of adamantane have been patented as
antiviral agents against HIV [13] and Choi’s group reported adamantane containing DGAT1
inhibitor [7]
Fig. 3.
We herein describe the synthesis, structure-activity relationships (SAR), and optimization of
DGAT1 inhibitors based on the adamantane carboxylic acid core structure 7.
2
. Chemistry
Compounds 7, 8, 10, 12 and 19a-e were prepared as described in Scheme 1. The commercially
available 4-oxo-adamantane-1-carboxylic acid methyl ester 1 was reduced using sodium
borohydride (NaBH
reaction with benzyl 4-hydroxybenzoate (3) followed by hydrogenation to give acid intermediate
. The acid intermediate 5 was coupled with 1-(tert-butyloxycarbonyl)ethylenediamine 14,
4
) to afford adamantanol 2, which subsequently underwent the Mitsunobu
5
which is synthesized from ethylenediamine 13, to give the coupled product 6. Subsequent
hydrolysis or tert-butyl deprotection gave compounds 7 and 9, respectively. Amine intermediate
9
was treated with phenylisocyanate and benzenesulfonyl chloride followed by ester hydrolysis

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to give the desired acid derivatives 10 and 12. Also, Boc-deprotection of 7 afforded amine
hydrochloride 8.
Condensation of the intermediate 14 with the appropriate carboxylic acids 15a-e followed by
acidic deprotection afforded amine hydrochlorides 17a-e. Subsequent condensation with acid
intermediate 5 followed by hydrolysis, afforded desired acid derivatives 19a-e.
A Horner-Wadsworth-Emmons (HWE) reaction between 5-hydroxy-2-adamantanone 20 and
trimethyl phosphonoacetate 21 provided α, β-unsaturated ester 22, which was hydrogenated to
give saturated alcohol 23. Compound 24 synthesized by Mitsunobu reaction of alcohol 23 with 3,
subsequent debenzylation gave acid 25. This was further coupled with amine intermediates 17b,
c and hydrolyzed to give desired acid 27b,c.
In order to obtain three carbon linked adamantane derivatives, (3-aminopropyl)carbamic acid
tert-butyl ester 28 was condensed with carboxylic acids 15b, c followed by acidic deprotection to
afford amine hydrochlorides 30b, c. Further condensation with acid intermediates 5 followed by
hydrolysis gave desired derivatives 32b, c (Scheme 2).
Z-isomer 37 and E-isomer 39 adamantane carboxylic acids were synthesized as described in
Scheme 3. Esterification of 4-hydroxybenzoic acid (33) gave tert-butyl ester 34. Ester 34
underwent Mitsunobu reaction with adamantanol 2 to afforded Z- and E-mixture of 35. Z-isomer
3
6 and E-isomer 38 were separated by silica gel column chromatography from mixture 35, and
both compounds were crystallized from methanol giving off white needle-like single crystals,
suitable for X-ray crystallographic analysis. Fig. 4 and 5 illustrate the molecular structures of the
Z-isomer 36 and E-isomer 38, which were subsequently deprotected with trifluoroacetic acid
(TFA) to give the individual Z-isomer and E-isomer carboxylic acids 37 and 39, respectively.

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Condensation of the intermediate 14 with the appropriate carboxylic acids 44a-g, followed by
acidic deprotection afforded amine hydrochlorides 46a-g. The resulting amine hydrochlorides
4
6a-g were condensed with the corresponding acid intermediates 39 and hydrolyzed to give the
desired acid derivatives 48a-g (Scheme 5).
3
. RESULTS AND DISCUSSION
A high-throughput screening (HTS) of our small molecule library resulted in the identification of
compound 7 as a novel and moderately potent DGAT1 inhibitor (Fig. 2). From initial
implementation, we considered 7 to be a good candidate for lead optimization based on its
moderate inhibitory activity. As a next step, we attempted to replace the tert-butyl carbamate
group with the parent amine hydrochloride 8, but this change resulted in the loss of DGAT1
potency. We next tried to replace tert-butyl carbamate group with urea 10, sulfonamide 12,
benzamide 19a and napthamide 19b. Of these, 19b turned out to be successful exhibiting an
enhanced potency (IC50 = 34 nM) as compared to carbamate 7. Additionally, we synthesized a
biphenyl analogue 19c with improved potency (IC = 12 nM). Replacement of the phenyl ring
5
0
with a heteroaromatic ring (to decrease the overall lipophilicity) afforded the oxazole derivative
9d (IC = 89 nM). When we changed oxazole into pyrazole (analogue 19e), DGAT1 inhibitory
1
5
0
activity was lost (Table 1). From these data, we further investigated the SAR of napthamide 19b
and biphenyl analogue 19c.
Scheme 1
Table 1.

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As shown in Table 2, introduction of adamantane acetic acid derivatives (27b, IC50 > 500 nM)
possessing naphthamide analogue resulted in greatly diminished DGAT1 potency and 27c (IC50
=
159 nM) biphenyl substituent appeared moderate tolerated at the DGAT1inhibitory activity.
Extension of the carbon chain i.e., ethylene group to a propylene group (compound 32b and 32c)
resulted in loss of DGAT1 inhibitory activity.
Scheme 2:
Table 2.
As shown in Table 1, we found potent naphthalene analogue 19b and biphenyl analogue 19c,
which are mixtures of Z-isomer and E-isomer showing nanomolar in vitro potency respectively.
Therefore, we synthesized the individual isomers of 19b and 19c as shown in Table 3. In each
case, the E-isomer showed better in vitro potency as compared to Z-isomer (compounds 43b and
4
3c). Compound 43c showed the most potent in vitro potency therefore, it was further modified.
Scheme 3:
Fig. 4.
Fig. 5.

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Condensation of the amine hydrochloride intermediates 17b, c with acid intermediates 37 and 39
followed by hydrolysis to give the desired acid derivatives 41b, c, and 43b, c (Scheme 4).
Scheme 4:
Table 3.
As a next step we attempted to investigate further SAR for substituent on the biphenyl ring. As
shown in Table 4, we incorporated methyl group on biphenyl ring. 48a showed an improvement
in mouse DGAT1 inhibitory activity with an IC value of 2 nM, but at the same time a 6-fold
5
0
reduction in human DGAT1 potency. Also we introduced trifluoromethyl and chloro substituents
on biphenyl ring. Replacement of methyl group with trifluoromethyl and chloro resulted in loss
of DGAT1 inhibitory activity. Further we investigated disubstituted derivatives on aromatic ring.
As an insertion of one more methyl group on 48a (compound 48e, IC = 105 nM), showed
5
0
decrease in the human DGAT1 potency. In addition, dichloro (48f, IC50 = 280 nM) and difluoro
analogue (48g, IC50 = 170 nM) (electron withdrawing group) showed no improvement.
Compound 43c showed the most potent in vitro potency than substituted biphenyl ring analogues
therefore, it was further evaluated for its druggability and in vivo efficacy.
Scheme 5:
Table 4

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The epimerization of carboxylic acid is known and has been previously studied in detail in the
case of ibuprofen and DGAT inhibitor [14, 15, 7a,b].
Fig. 6.
Usually epimerization occurs at the α-proton on the carbon atom attached to the carboxylic acid
group but in our case, the carboxylic acid group is attached to a tertiary carbon that eliminating
the possibility of epimerization. Discovery of biphenyl adamantane carboxylic acid analogue 43c
provided a molecule that could not undergo epimerization while improved DGAT1 potency by
an order of magnitude compared to hit 7.
As shown in Table 5, 43c exhibited good selectivity against DGAT-2 and stability in human liver
microsome, and showed no significant inhibition in any of the major CYP isoforms (1A2, 2C9,
2
C19, 2D6, and 3A4). Moreover, 43c did not inhibit the hERG channel, has reasonable
permeability and no cytotoxicity.
Table 5.
To evaluate the in vivo efficacy of 43c, the oral lipid tolerance test (OLTT), an acute lipid
challenge model measuring TG change after a corn oil bolus dosing was performed. Normal
(C57BL/6 mice) and diabetic mice (TallyHo mice) [16] were treated with vehicle (0.5%
carboxymethyl cellulose, CMC) or 43c (3 mg/kg) at 30 min prior to corn oil dosing, blood
samples for TG measurement were taken at 2 h post-lipid challenge. As can be seen in Fig. 7,
compound 43c reduced plasma TG levels in the blood by over 95% compared to vehicle at an

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oral dose of 3 mg/kg in normal (A) and diabetic mice (B). Also, Fig 7 (C) shows that compound
4
3c was highly efficacious in reducing plasma TG, exhibiting ~100% inhibition at doses of 0.5, 1
and 10 mg/kg.
Fig. 7.
Recently, we reported lipid staining dyes “LipidGreen” and “LipidGreen2”, [17] which
effectively stained fat deposits in live zebrafish. We performed TG reduction efficacy after 43c
treatment in vivo for 3 days. As shown in Fig. 8, 43c significantly decreased the lipid deposits
compared to an untreated control in live zebrafish.
Fig. 8.
We examined the PK profile of compound 43c. As shown in Table 6, compound 43c the
maximal plasma concentration (Cmax) of 0.24±0.14 µg·hr/mL appeared and the AUC value was
0
.12 µg/mL after oral administration. The oral bioavailability was 13.4 %. To investigate PK and
PD correlation, we examined intestinal disposition of 43c. DGAT1 is mainly expressed in
intestine [18]. Whole mouse small intestine was collected to estimate the total intestinal
concentration of 43c could represent total amount in the intestinal area including lumen.
Separately, intestinal tissue was prepared by flushing with phosphate buffered saline (PBS) to
remove the drug which had not penetrated the enterocyte. The drug concentration in whole
intestine and enterocyte were 430 and 104-fold, respectively, higher than the plasma at Tmax
demonstrating that most of the dosed 43c tended to remain locally in the intestine (Table 7).

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These results also propose that the characteristics of 43c expressing local exposure to the target
organ, intestine could be critical in achieving its therapeutic efficacy.
Table 6.
Table 7.
Compound 43c was evaluated for in vivo efficacy in body weight gain reduction and glucose
lowering efficacy in a diet-induced obesity (DIO) mouse model (Fig. 9). Treatment with 43c for
4
weeks resulted in a trend towards reduced in body weight gain by ~6% without affecting food
intake (Fig. 9A) compared to the control mice at a dose of 10 mg/kg. After 4 weeks of treatment
with 43c, an oral glucose tolerance test (OGTT) was performed, and 43c significantly reduced
the glucose AUC by 54% compared to DIO vehicle control (Fig. 9B).
Fig. 9.
4
. Conclusions
In this study, a new series of adamantane carboxylic acid derivatives was identified and
evaluated for their ability to inhibit DGAT1. Compound 43c showed good in vitro activity
against human and mouse DGAT1, liver microsomal stability, safety profiles such as CYP
inhibition, hERG and cytotoxicity. Compound 43c significantly reduced blood TG level after a
corn oil challenge in mice and zebrafish, and also reduced body weight gain and glucose AUC
after 4 weeks treatment in DIO mice.

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5
. Experimental
5
.1. Materials and methods
Melting points were determined on an MEL-TEMP apparatus and are uncorrected. IR Spectra
were obtained on a Smith ATR-FT-IR spectrometer and the absorption frequencies are reported
-1
1
in wavelength (cm ). H NMR spectra were run on Bruker AVANCE-500, Bruker AVANCE-
3
00 and Varian OXFORD-300 spectrometers at 500 and 300 MHz. Chemical shifts (δ) are
expressed in ppm downfield from TMS as internal standard. The letters s, d, t, q, and m are used
to indicate singlet, doublet, triplet, quadruplet, and multiplet, respectively. High-resolution mass
spectra were obtained on the Autospec Magnetic sector mass spectrometer (Micromass,
Manchester, UK). The reactions were monitored by thin-layer chromatography (TLC) and
column chromatography was performed using Chromatorex GS60-40/75. X-ray diffraction
crystal structure analysis was obtained on Bruker SMART APEX II.
5
.2. Chemistry
Unless mentioned otherwise all reactions were performed under atmosphere. All anhydrous
solvents (stored over molecular sieves) and chemicals were obtained from standard commercial
vendors and were used without any further purification.
5
.2.1. E- and Z-4-Hydroxyadamantane-1-carboxylic acid methyl ester (2)
To a stirred solution of 4-oxoadamantane-1-carboxylic acid methyl ester 1 (6 g, 28.811 mmol),
in MeOH (60 mL), powdered NaBH (1.19 g, 31.692 mmol) was added cautiously in three
4
portions at room temperature. The mixture was stirred for 4 h and concentrated under reduced
pressure to remove the bulk of the methanol. The residue was diluted with 5% aqueous HCl (20
mL) extracted with dichloromethane (2 X 200 mL). The combined organic layers were washed

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with brine (50 mL), dried over anhydrous sodium sulfate. Evaporation of solvents gave ~60/40
1
(
E/Z) mixture of the epimeric alcohols 2 as a colorless oil (5.9 g, 97%). H NMR (300 MHz,
CDCl3): δ
3.92-3.80 (m, 1H), 3.69-3.61 (m, 3H), 2.30-1.36 (m, 13 H); LC-MS (m/z): 211
+
[
M+H] .
5
.2.2. E- and Z-4-(4-Benzyloxycarbonyl-phenoxy)-adamantane-1-carboxylic acid methyl ester
(
4)
To a solution of benzyl 4-hydroxybenzoate 3 (3 g, 13.144 mmol) and triphenyl phospine (4.14 g,
5.77 mmol), dissolved in THF (50 mL) was added E- and Z-4-hydroxy-adamantane-1-
1
carboxylic acid methyl ester 2 (3.317 g, 15.773 mmol). The reaction mixture was heated to
reflux and DIAD (3.096 mL, 15.773 mmol) was added drop wise at reflux over 2 h. The
resulting mixture was stirred under reflux for 16 h. The volume was reduced by evaporation and
the resulting mixture was added water (50 mL) followed by extraction with DCM (3 x 200 mL).
The combined organic phases were washed with brine (100 mL), dried over Na SO , filtered and
2
4
the volatiles evaporated in vacuo. Crude product was purified by column Chromatography using
hexane followed by a mixture of EtOAc/hexanes (1:10) .Combined fractions were evaporated in
vacuum afforded E- and Z-4-(4-benzyloxycarbonyl-phenoxy)-adamantane-1-carboxylic acid
1
methyl ester 4 as an oil (3.3 g, 60 %). H NMR (300 MHz, CDCl ):
δ

8.05-7.97 (m, 2H), 7.47-
3
7
.29 (m, 5H), 6.96-6.87 (m, 2H), 5.33 (s, 2H), 4.52-4.41 (m, 1H), 3.70-3.63 (m, 3H), 2.33-1.45
+
(
m, 13H); LC-MS (m/z): 421 [M+H] .
5
.2.3. E- and Z -4-(4-Carboxyphenoxy)adamantane-1-carboxylic acid methyl ester (5)
To a solution of E- and Z-4-(4-benzyloxycarbonylphenoxy)adamantane-1-carboxylic acid methyl
ester 4 (3.2 g, 7.61 mmol) dissolved in ethyl acetate (100 mL) was added 10% (w/w) palladium

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on carbon (0.32 g) and resulting mixture was hydrogenated using hydrogen balloon. The catalyst
filtered off through celite and the filtrate evaporated in vacuo afforded E- and Z-4-(4-
1
carboxyphenoxy)adamantane-1-carboxylic acid methyl ester 5 as a white solid (2.5 g, 99%). H
NMR (300 MHz, CDCl3):
δ

8.04 (d, J = 7.83 Hz, 2H), 6.95 (d, J = 8.19 Hz, 2H), 4.55-4.42 (m,
+
1
H), 3.73-3.62 (m, 3H), 2.35-2.66 (m, 12H), 1.57-1.45 (m, 1H); LC-MS (m/z): 331 [M+H] .
5
.2.4. (2-Aminoethyl)carbamic acid tert-butyl ester (14)
A solution of di-tert-butyl dicarbonate (3.63 g, 16.639 mmol) in dichloromethane (200 mL) was
added dropwise to a solution of ethylenediamine (10 g, 166.39 mmol) in dichloromethane (50
mL) over 6 h with vigorous stirring. Stirring was continued for 24 h at room temperature.
Removed undissolved solid through filtration and washed with dichloromethane. Collected
filtrate were washed with aqueous sodium carbonate and brine , dried over anhydrous sodium
sulfate and evaporated under reduced pressure to offered the crude product which was purified
by silica gel column chromatography to give (2-aminoethyl)carbamic acid tert-butyl ester 14 as a
1
colorless viscous liquid (5 g, 19 %). H NMR (300 MHz, CDCl
3
):
δ

4.88 (bs, 1H), 3.17 (q, J =
+
5
.76 Hz, 2H), 2.79 (t, J = 6 Hz, 2H), 1.44 (s, 9H), 1.13 (s, 2H); LC-MS (m/z): 161.02 [M+H] .
5.2.5. E- and Z- 4-[4-(2-tert-Butoxycarbonylaminoethylcarbamoyl)phenoxy]adamantane-1-
carboxylic acid methyl ester (6)
A mixture of E- and Z-4-(4-carboxyphenoxy)adamantane-1-carboxylic acid methyl ester 5 (300
mg, 0.908 mmol), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI)
(435.19 mg, 2.27 mmol), tert-butyl (2-aminoethyl)carbamate 14 (160.03 mg, 0.99 mmol) and 1-
hydroxybenzotriazole monohydrate (HOBt) (184.06 mg, 1.362 mmol) in dichloromethane (7
mL) was stirred for 24 h at room temperature. The reaction mixture was diluted with aqueous

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NaHCO
3
and extracted with dichloromethane. The extracts were washed with brine, dried over
anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by silica gel
column chromatography to give E- and Z- 4-[4-(2-tert-
butoxycarbonylaminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid methyl ester 6
1
(
386 mg, 89%) as a white solid. H NMR (300 MHz, CDCl ):
δ

7.75 (d, J = 8.34 Hz, 2H), 6.99
3
(bs, 1H), 6.92 (d, J = 8.15 Hz, 2H), 4.96 (bs, 1H), 4.51-4.38 (m, 1H), 3.71-3.63 (m, 3H), 3.58-
+
3
.48 (m, 2H), 3.45-3.33 (m, 2H), 2.33-1.46 (m, 13H), 1.42 (s, 9H); LC-MS (m/z): 473 [M+H] .
5.2.6. E- and Z-4-[4-(2-tert-Butoxycarbonylaminoethylcarbamoyl)phenoxy]adamantane-1-
carboxylic acid (7)
A solution of E- and Z-4-[4-(2-tert-butoxycarbonylaminoethylcarbamoyl)phenoxy]adamantane-
1
-carboxylic acid methyl ester 6 (100 mg, 0.212 mmol) in THF (35 mL) and MeOH (35 mL) was
treated with aqueous 1M sodium hydroxide solution (42.32 mg, 1.058 mmol) at 40 °C for 12 h.
After this time, the solution was cooled to room temperature, and the volume was reduced by
rotary evaporation to 35 mL. The resulting solution was acidified with 1N hydrochloric acid to
pH 4-5. More water was added (50 mL) and the aqueous solution was extracted with EtOAc (3 x
5
0 mL). The combined organic layer was washed with brine, dried over sodium sulfate and
concentrated. A crude product was isolated form acetonitrile to afford the title compound E- and
Z-4-[4-(2-tert-butoxycarbonylaminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid 7
1
(
83 mg, 85%) as a white solid. H NMR (300 MHz, DMSO-d
6
):
δ

12.11 (s, 1H), 8.27 (t, J =
5
4
.36 Hz, 1H), 7.78 (d, J = 8.55 Hz, 2H), 7.02 (d, J = 8.80 Hz, 2H), 6.88 (t, J = 5.65 Hz, 1H),
.63-4.53 (m, 1H), 3.25 (q, J = 6.03 Hz, 2H), 3.07 (q, J = 6.03 Hz, 2H), 2.20-1.40 (m, 13H), 1.36
+
-1
(
s, 9H); LC-MS (m/z): 459 [M+H] ; IR (ATR) ν max cm : 3442, 3322, 2928, 1715, 1649, 1545,

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1
497, 1289, 1246, 1233, 1179, 1156, 681; Anal. Calcd for C25
34 2 6
H N O : C, 65.48; H,7.47; N,6.11.
Found: C,65.26; H,7.54; N,6.02.
5.2.7. E- and Z-4-[4-(2-Aminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid,
hydrochloride (8)
To a mixture of E- and Z-4-[4-(2-tert-butoxycarbonylaminoethylcarbamoyl)phenoxy]-
adamantane-1-carboxylic acid 7 (30 mg, 0.076 mmol) in ethyl acetate (2 mL) was added
hydrogen chloride 4.0 M solution in 1,4-dioxane (1 mL) and the mixture was stirred for 12 h.
The mixture was concentrated to minimum volume and the residue was collected by filtration to
give
E-
and
Z-4-[4-(2-aminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic
acid
1
hydrochloride 8 (30 mg, 99%) as a white solid. H NMR (500 MHz, DMSO-d ):
δ

8.43 (s, 1H),
6
7
.84 (d, J = 6.61 Hz, 2H), 7.05 (d, J = 6.89 Hz, 2H), 4.65-4.55 (m, 1H), 3.51-3.44 (m, 2H), 2.96
+
-1
(
t, J = 6.14 Hz, 2H), 2.21-1.39 (m, 13H); LC-MS (m/z): 359 [M+H] ; IR (ATR) ν max cm : 3217,
2
924, 2858, 16.70, 1606, 1560, 1506, 1302, 1251, 1018, 850; Anal. Calcd for C H ClN O :
20 27 2 4
C,60.83; H,6.89; N,7.09. Found: C,60.9; H,6.93; N,6.85.
5.2.8. E- and Z-4-[4-(2-Aminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid methyl
ester, hydrochloride salt (9)
To a solution of E- and Z-4-[4-(2-tert-butoxycarbonylaminoethylcarbamoyl)phenoxy]-
adamantane-1-carboxylic acid methyl ester 6 (65 mg, 0.138 mmol) in ethyl acetate (6 mL) was
added 4.0 M hydrogen chloride solution in 1,4-dioxane (0.5 mL) and stirring continued for 24 h.
The reaction mixture was concentrated in vacuo and the residue was collected by filtration to
give E- and Z-4-[4-(2-aminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid methyl
1
ester, hydrochloride salt 9 (55 mg, 98 %) as a white solid. H NMR (300 MHz, DMSO-d ):
6

ACCEPTED MANUSCRIPT
δ
4
1

8.58 (t, J = 5.45 Hz, 1H), 8.01 (s, 3H), 7.86 (d, J = 8.67 Hz, 2H), 7.09-7.00 (m, 2H), 4.66-
.54 (m, 1H), 3.62-3.57 (m, 3H), 3.49 (q, J = 5.73 Hz, 2H), 3.02-2.90 (m, 2H), 2.21-1.39 (m,
+
3H); LC-MS (m/z): 373 [M+H] .
5.2.9. E- and Z-4-{4-[2-(3-Phenylureido)ethylcarbamoyl]phenoxy}adamantane-1-carboxylic
acid (10)
To a solution of E- and Z-4-[4-(2-aminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid
methyl ester, hydrochloride 9 (56 mg, 0.137 mmol) in dichloromethane (5 mL) was added
phenylisocyanate (16.13 mg, 0.137 mmol) and triethyl amine (27.72 mg, 0.274 mmol). The
reaction mixture was stirred for 12 h at room temperature. The reaction mixture was diluted with
H O and extracted with dichloromethane. Organic layer was separated, dried over anhydrous
2
sodium sulfate, and evaporated under reduced pressure. The residue was purified by silica gel
column chromatography to give E- and Z-4-{4-[2-(3-phenylureido)ethylcarbamoyl]phenoxy}-
adamantane-1-carboxylic acid methyl ester (61 mg, 91 %).
In which added THF (30 mL) and MeOH (30 mL) was treated with aqueous 1M sodium
hydroxide solution (24.82 mg, 0.62 mmol) at 40 °C for 12 h. After this time, the solution was
cooled to room temperature, and the volume was reduced by rotary evaporation. The resulting
solution was acidified with 1N hydrochloric acid to pH 2. More water was added (50 mL) and
the aqueous solution was extracted with EtOAc (3 x 50 mL). The combined organic layer was
washed with brine, dried over sodium sulfate and concentrated. A crude product was isolated
form ethyl acetate/ hexane to afford the title compound E- and Z-4-{4-[2-(3-
phenylureido)ethylcarbamoyl]phenoxy}adamantane-1-carboxylic acid 10 (50 mg, 84%) as a
1
white solid. H NMR (500 MHz, DMSO-d ):
δ

12.08 (s, 1H), 8.53 (s, 1H), 8.37 (t, J = 4.12 Hz,
6

ACCEPTED MANUSCRIPT
1
9
3
2
H), 7.81 (d, J = 8.54 Hz, 2H), 7.38 (d, J = 7.98 Hz, 2H), 7.20 (t, J = 7.89 Hz, 2H), 7.02 (dd, J =
.00, 2.78 Hz, 2H), 6.87 (t, J = 7.24 Hz, 1H), 6.25 (t, J = 5.10 Hz, 1H), 4.63-4.52 (m, 1H), 3.38-
+
-1
.19 (m, 4H), 2.21-1.38 (m, 13H). LC-MS (m/z): 478 [M+H] ; IR (ATR) ν max cm : 3311, 2929,
860, 1690, 1653, 1625, 1552, 1499, 1293, 1233, 1029, 750; Anal. Calcd for C27
31 3 5
H N O :
C,67.91; H,6.54; N,8.58. Found: C,67.72; H,6.57; N,8.58.
5.2.10.
E- and Z-4-[4-(2-Benzenesulfonylaminoethylcarbamoyl)phenoxy]adamantane-1-
carboxylic acid (12)
To a solution of E- and Z-4-[4-(2-aminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid
methyl ester, hydrochloride 9 (50 mg, 0.122 mmol) in dichloromethane (5 mL) was added
benzenesulfonyl chloride (21.6 mg, 0.122 mmol) and triethyl amine (24.75 mg, 0.245 mmol)
stirred for 12 h at room temperature. The reaction mixture was diluted with H O and extracted
2
with dichloromethane. Organic layer was separated, dried over anhydrous sodium sulfate, and
evaporated under reduced pressure. The residue was purified by silica gel column
chromatography to give E- and Z-4-[4-(2-benzenesulfonylaminoethylcarbamoyl)phenoxy]-
adamantane-1-carboxylic acid methyl ester 11 (49 mg, 70 %).
In which added THF (30 mL) and MeOH (30 mL) was treated with 1M sodium hydroxide
solution (19.12 mg, 0.478 mmol) at 40 °C for 12 h. After this time, the solution was cooled to
room temperature, and the volume was reduced by rotary evaporation. The resulting solution was
acidified with 1N hydrochloric acid to pH 2. More water was added (50 mL) and the aqueous
solution was extracted with EtOAc (3 x 50 mL). The combined organic layer was washed with
brine, dried over sodium sulfate and concentrated. A crude product was isolated form ethyl
acetate/ hexane to afford the title compound E- and Z-4-[4-(2-benzenesulfonylamino-

ACCEPTED MANUSCRIPT
1
ethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid 12 (39 mg, 81%) as a white solid. H
NMR (300 MHz, DMSO-d6):
12.10 (s, 1H), 8.32-8.26 (m, 1H), 7.80-7.70 (m, 5H), 7.64-7.54
m, 3H), 7.02-6.97 (m, 2H), 4.61-4.52 (m, 1H), 3.26 (q, J = 6.34 Hz, 2H), 2.87 (q, J = 6.56 Hz,
δ
(
+
-1
2
H), 2.18-1.39 (m, 13H); LC-MS (m/z): 499 [M+H] ; IR (ATR)
ν max cm : 3249, 2913, 2859,
1
603, 1499, 1320, 1243, 1155, 1091, 1019, 951, 843, 753, 688; Anal. Calcd for C H N O S:
2
6
30
2
6
C,62.63; H,6.07; N,5.62. Found: C,62.75; H,6.30; N,5.35.
5.2.11. Naphthalene-2-carboxylic acid (2-aminoethyl)amide hydrochloride (17b)
A mixture of (2-aminoethyl)carbamic acid tert-butyl ester 14 (100 mg, 0.624 mmol), EDCI
(
299.13 mg, 1.56 mmol), naphthalene-2-carboxylic acid (107.47 mg, 0.624 mmol), HOBt
126.52 mg, 0.936 mmol) and hünig's base (283.01 mg, 2.185 mmol) in dichloromethane (6 mL)
(
3
was stirred for 2 days. The reaction mixture was diluted with aqueous NaHCO and extracted
with dichloromethane. The extracts were washed with brine, dried over anhydrous sodium
sulfate and concentrated in vacuum. The residue was purified by silica gel column
chromatography to give {2-[(naphthalene-2-carbonyl)amino]ethyl}carbamic acid tert-butyl ester
1
6b (157 mg, 80%).
To a mixture of {2-[(naphthalene-2-carbonyl)amino]ethyl}carbamic acid tert-butyl ester 16b
157 mg, 1.23 mmol) in ethyl acetate (7 mL) was added hydrogen chloride 4.0 M solution in 1,4
(
dioxane (1 mL) and the mixture was stirred for 12 h. The mixture was concentrated to minimum
volume and the residue was collected by filtration to obtained naphthalene-2-carboxylic acid (2-
amino-ethyl)-amide hydrochloride 17b (119 mg, 95%) as a white solid. Product was used for
1
next step without further purification. H NMR (300 MHz, DMSO-d ):
δ

8.94 (t, J = 5.36 Hz,
6

ACCEPTED MANUSCRIPT
1
3
H), 8.55 (s, 1H), 8.11 (s, 3H), 8.05-7.94 (m, 4H), 7.66-7.55 (m, 2H), 3.58 (q, J = 5.87 Hz, 2H),
+
.03 (q, J = 5.97 Hz, 2H); LC-MS (m/z): 215 [M+H] .
The following compounds 17a, c- e prepared from the corresponding starting materials in a
similar manner to that described for 17b.
5.2.12. N-(2-Aminoethyl)benzamide hydrochloride (17a)
Using the procedure for 17b with benzoic acid provided the title compound as a white solid in
1
8
8% yield. H NMR (300 MHz, DMSO-d
6
):
δ

8.83-8.70 (m, 1H), 8.21-7.99 (m, 3H), 7.96-7.88
(m, 2H), 7.58-7.42 (m, 3H), 3.53 (q, J = 5.86 Hz, 2H), 2.98 (t, J = 6.19 Hz, 2H); LC-MS (m/z):
+
1
65 [M+H] .
5.2.13. Biphenyl-4-carboxylic acid (2-aminoethyl)-amide hydrochloride (17c)
Using the procedure for 17b with biphenyl-4-carboxylic acid provided the title compound as a
1
white solid in 84% yield. H NMR (300 MHz, DMSO-d
6
):
δ

8.83 (t, J = 5.40 Hz, 1H), 8.10 (s,
3
3
H), 8.02 (d, J = 8.28 Hz, 2H), 7.83-7.70 (m, 4H), 7.54-7.37 (m, 3H), 3.55 (q, J = 5.94 Hz, 2H),
+
.06-2.93 (m, 2H); LC-MS (m/z): 241 [M+H] .
5.2.14. 2-Phenyl-5-trifluoromethyloxazole-4-carboxylic acid (2-aminoethyl)amide hydrochloride
(17d)
Using the procedure for 17b with 2-phenyl-5-trifuoromethyloxazole-4-carboxylic acid provided
1
the title compound as a white solid in 79% yield. H NMR (300 MHz, DMSO-d
6
):
δ

8.94 (t, J =
5
.72 Hz, 1H), 8.13-8.01 (m, 5H), 7.52-7.59 (m, 3H), 3.55 (q, J = 6.00 Hz, 2H), 3.00 (t, J = 6.35
+
Hz, 2H); LC-MS (m/z): 300 [M+H] .

ACCEPTED MANUSCRIPT
5.2.15.
1-Phenyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid (2-aminoethyl)amide
hydrochloride (17e)
Using the procedure for 17b with 1-phenyl-3-trifuoromethyl-1H-pyrazole-4-carboxylic acid
1
provided the title compound as a white solid in 82% yield. H NMR (300 MHz, DMSO-d
6
):
δ

9.46 (s, 1H), 8.84 (t, J = 5.36 Hz, 1H), 8.05 (s, 3H), 7.86-7.79 (m, 2H), 7.65-7.57 (m, 2H),
7
.52-7.44 (m, 1H), 3.49 (q, J = 5.78 Hz, 2H), 2.99 (q, J = 6.21 Hz, 2H); LC-MS (m/z): 299
+
[
M+H] .
5.2.16. E- and Z-4-[4-(2-Benzoylaminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid
(19a)
A mixture of E-and Z-4-(4-carboxyphenoxy)adamantane-1-carboxylic acid methyl ester 5 (80
mg, 0.225 mmol), EDCI (108.06 mg, 0.564 mmol), N-(2-amino-ethyl)-benzamide hydrochloride
1
7a (49.77 mg, 0.248 mmol), HOBt (45.7 mg, 0.338 mmol) and hünig's base (102.24 mg, 0.789
mmol) in dichloromethane (8 mL) was stirred for 24 h. The reaction mixture was diluted with
aqueous NaHCO and extracted with dichloromethane. The extracts were washed with brine,
3
dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by
silica gel column chromatography to give E- and Z-4-[4-(2-benzoylaminoethylcarbamoyl)-
phenoxy]adamantane-1-carboxylic acid methyl ester 18a (75 mg, 70 %).
To a solution of 4-[4-(2-benzoylaminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid
methyl ester 18a (75 mg, 0.157 mmol) in THF/water (20 mL, 3:1) was added NaOH (31.48 mg,
0
.787 mmol). The reaction mixture was stirred at ambient temperature for 24 h. The THF was
removed in vacuo and resulting solution was acidified with 1N hydrochloric acid to pH 2-3.
More water was added (100 mL) and the aqueous solution was extracted with EtOAc (3 x 50

ACCEPTED MANUSCRIPT
mL). The combined organic layer was washed with brine, dried over sodium sulfate and
concentrated. A crude product was isolated form acetonitrile to afford E- and Z-4-[4-(2-
benzoylaminoethylcarbamoyl)phenoxy]adamantane-1-carboxylic acid 19a (69 mg, 95%) as a
1
white solid. H NMR (300 MHz, DMSO-d ):
δ

12.10 (s, 1H), 8.83-8.70 (m, 2H), 7.86-7.70 (m,
6
4
H), 7.62-7.49 (m, 3H), 6.99-6.90 (m, 2H), 3.61 (s, 4H), 4.63-4.52 (m, 1H), 2.21-1.38 (m, 13H);
+
-1
LC-MS (m/z): 463 [M+H] ; IR (ATR) ν max cm : 3400, 3311, 2910, 2860, 1690, 1630, 1550,
1
499, 1242, 1233, 1180, 750; Anal. Calcd for C H N2O : C,71.11; H,6.54; N,6.06. Found:
27 30 5
C,69.93; H,6.44; N,5.91.
The following compounds 19b, c, d, e was prepared from the corresponding starting
materials in a similar manner to that described for 19a.
5.2.17. E-andZ-4-(4-{2-[(Naphthalene-2-carbonyl)amino]ethylcarbamoyl}phenoxy)adamantane-
1
-carboxylic acid (19b)
Using the procedure for 19a with naphthalene-2-carboxylic acid (2-aminoethyl)amide
1
hydrochloride 17b provided the title compound as a white solid in 86% yield.; H NMR (300
MHz, DMSO-d
6
):
δ
12.11 (s, 1H), 8.84-8.72 (m, 1H), 8.54-8.41 (m, 2H), 8.06-7.89 (m, 4H),
7
2
3
.81 (d, J = 8.28 Hz, 2H), 7.65-7.54 (m, 2H), 7.10-6.97 (m, 2H), 4.65-4.52 (m, 1H), 3.54-341(m,
+
-1
H), 3.40-3.25 (m, 2H), 2.21-1.36 (m, 13H); LC-MS (m/z): 513 [M+H] ; IR (ATR) ν max cm :
397, 3308, 2918, 2858, 1707, 1618, 1541, 1535, 1499, 1288, 1240, 1229, 1183, 1085, 764; Anal.
Calcd for C H N O : C,72.64; H,6.29; N,5.47. Found: C,72.24; H,6.43; N,5.31.
3
1
32
2
5
5.2.18. E-andZ-4-(4-{2-[(Biphenyl-4-arbonyl)amino]ethylcarbamoyl}phenoxy)adamantane-1-
carboxylic acid (19c)

ACCEPTED MANUSCRIPT
Using the procedure for 19a with biphenyl-4-carboxylic acid (2-aminoethyl)amide hydrochloride
1
1
7c provided the title compound as a white solid in 88% yield. H NMR (500 MHz, DMSO-d ):
6
δ

12.10 (s, 1H), 8.69-8.61 (m, 1H), 8.50-8.42 (m, 1H), 7.94 (d, J = 8.28 Hz, 2H), 7.83-7.70 (m,
H), 7.49 (t, J = 7.82 Hz, 2H), 7.40 (t, J = 7.26 Hz, 1H), 7.05-7.00 (m, 2H), 4.63-4.53 (m, 1H),
6
+
-1
3
.44 (s, 4H), 2.21-1.39 (m, 13H); LC-MS (m/z): 539 [M+H] . IR (ATR) ν max cm : 3402,3311,
2
912, 2857, 1707, 1629, 1538, 1499, 1242, 1231, 1180, 745; Anal. Calcd for C H N O :
3
3
34
2
5
C,73.59; H,6.36; N,5.20. Found: C,73.26; H,6.37; N,5.06.
5.2.19.E-andZ-4-(4-{2-[(2-Phenyl-5-trifluoromethyloxazole-4-carbonyl)amino]ethylcarbamoyl}-
phenoxy)adamantane-1-carboxylic acid (19d)
Using the procedure for 19a with 2-phenyl-5-trifluoromethyl-oxazole-4-carboxylic acid (2-
aminoethyl)amide hydrochloride 17d provided the title compound as a white solid in 81% yield.
1
H NMR (300 MHz, DMSO-d6): δ
12.12 (s, 1H), 8.93-8.81 (m, 1H), 8.49-8.39 (m,1H), 8.07 (d,
J = 6.39 Hz, 2H), 7.80 (d, J = 8.56 Hz, 2H), 7.71-7.58 (m, 3H), 7.03 (d, J = 8.56 Hz, 2H), 4.65-
+
-
4
.52 (m, 1H), 3.44 (s, 4H), 2.21-1.38 (m, 13H); LC-MS (m/z): 598 [M+H] . IR (ATR) ν max cm
1
:
3407, 2933, 2861, 1683, 1502, 1372, 1243, 1182, 1145, 1093, 1016, 715, 689; Anal. Calcd for
C H F N O : C,62.31; H,5.06; N,7.03. Found: C,62.21; H,5.11; N,7.29.
31
30
3
3
6
5.2.20.
E-and
Z-4-(4-{2-[(1-Phenyl-3-trifluoromethyl-1H-pyrazole-4-carbonyl)amino]-
ethylcarbamoyl}phenoxy)adamantane-1-carboxylic acid (19e)
Using the procedure for 19a with 1-phenyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid (2-
aminoethyl)amide hydrochloride 17e provided the title compound as a white solid in 81% yield.
1
6
H NMR (500 MHz, DMSO-d ): δ
12.10 (s, 1H), 9.06 (s, 1H), 8.47 (d, J = 25.59 Hz, 2H), 7.80
(d, J = 7.59 Hz, 4H), 7.64-7.57 (m, 2H), 7.50-7.44 (m, 1H), 7.06-6.99 (m, 2H), 4.64-4.53 (m,

ACCEPTED MANUSCRIPT
+
-1
1
H), 3.40 (s, 4H), 2.21-1.39 (m, 13H); LC-MS (m/z): 597 [M+H] ; IR (ATR) ν max cm : 3338,
2
925, 2858, 1692, 1632, 1501, 1237, 1142, 760, 690; Anal. Calcd for C H F N4O5: C,62.41;
31
31 3
H,5.24; N,9.39. Found: C,62.35; H,5.25; N,8.98.
5.2.21. (5-Hydroxyadamantan-2-ylidene)acetic acid methyl ester (22)
To a solution of trimethyl phosponoacetate 21 (699.58 mg, 3.842 mmol) in anhydrous
tetrahydrofuran (15 mL) 60% suspension in minral oil of sodium hydride (200 mg, 4.802 mmol)
was added at 0 °C under nitrogen atmosphere and stirred for 1 h at the same temperature. Added
solution of 5-hydroxy-2-adamantanone 20 (500 mg, 3.201mmol) in tetrahydrofuran (5 mL)
slowly at room temperature. The reaction mixture was stirred for 5 h, quenched with water and
extracted with ethyl acetate. The combined organic phases were washed with brine, dried over
anhydrous Na SO . The solvent was removed under reduced pressure to provide (5-hydroxy-
2
4
1
adamantan-2-ylidene)acetic acid methyl ester 22 (641 mg, 90%). H NMR (300 MHz, DMSO-
d
6
):
δ

5.60 (s, 1H), 4.53 (s, 1H), 3.58 (s, 3H), 2.67-2.54 (m, 1H), 2.16-2.08 (m, 1H), 1.80-1.52
+
(
m, 11H); LC-MS (m/z): 223 [M+H] .
5.2.22. E- and Z-(5-Hydroxyadamantan-2-yl)acetic acid methyl ester (23)
To a solution of (5-hydroxyadamantan-2-ylidene)acetic acid methyl ester 22 (600 mg, 12.77
mmol) in ethyl acetate (25 mL), under nitrogen, was added 10% (w/w) palladium on carbon (60
mg). The atmosphere was replaced with hydrogen and the mixture stirred at room temperature
for 17 h. The reaction mixture was filtered and evaporated to obtained (5-hydroxyadamantan-2-
1
yl)acetic acid methyl ester 23 (590 mg, 97%) a colorless oil. H NMR (300 MHz, CDCl
3
):
δ

3.66 (s, 3H), 2.48-2.37 (m, 2H), 2.23-1.88 (m, 4H), 1.86-1.33 (m, 10H); LC-MS (m/z): 225
+
[
M+H] .

ACCEPTED MANUSCRIPT
5.2.23. E-and Z-4-(4-Methoxycarbonylmethyladamantan-1-yloxy)benzoic acid benzyl ester (24)
To a solution of benzyl 4-hydroxybenzoate 3 (1 g, 4.381 mmol) and triphenyl phospine (1.379 g,
.258 mmol), dissolved in benzene (100 mL) was added E/Z mixture (5-hydroxyadamantan-2-
5
yl)acetic acid methyl ester 23 (982.71 mg, 4.381 mmol). The reaction mixture was heated to
reflux and diisopropyl azodicarboxylate (DIAD) (1.032 mL, 5.258 mmol) was added drop wise
at reflux over 2 h. The resulting mixture was stirred under reflux for 16 h. The volume was
reduced by evaporation and the resulting mixture was added water (100 mL) followed by
extraction with Methylene chloride (3 x 200 mL). The combined organic phases were washed
with brine (100 mL), dried over anhydrous Na SO , filtered and the volatiles evaporated in
2
4
vacuo. Crude product was purified by column chromatography (elution gradient of 0−10%
EtOAc in hexane). Combined fractions were evaporated in vacuo afforded E- and Z- 4-(4-
methoxycarbonylmethyladamantan-1-yloxy)benzoic acid benzyl ester 24 (1.35 g, 71%) as an oil.
1
H NMR (300 MHz, CDCl3): δ
7.99 (d, J = 8.22 Hz, 2H), 7.48-7.29 (m, 5H), 7.01 (d, J = 8.35
Hz, 2H), 5.34 (s, 2H), 3.66 (s, 3H), 2.47-2.34 (m, 2H), 2.22-2.07 (m, 2H), 2.06-1.81 (m, 7H),
+
1
5
2
.81-1.62 (m, 4H), 1.40 (d, J = 13.05 Hz, 1H). LC-MS (m/z): 435 [M+H] .
.2.24. E-and Z-4-(4-Methoxycarbonylmethyladamantan-1-yloxy)benzoic acid (25)
5 was prepared from intermediate 24 (1.2 g, 2.76 mmol) according to the procedure described
for compound 5. The crude product was purified through column chromatography, eluting with
ethyl acetate in hexanes to give E- and Z-4-(4-methoxycarbonylmethyladamantan-1-yloxy)-
1
benzoic acid 25 (910 mg, 96%) as a white solid. H NMR (300 MHz, CDCl ):
δ

12.59 (s, 1H),
3
7
.87 (d, J = 8.62 Hz, 2H), 6.99 (d, J = 8.86 Hz, 2H), 4.04 (t, J = 6.57 Hz, 2H), 3.57 (s, 3H), 3.39

ACCEPTED MANUSCRIPT
(t, J = 6.31 Hz, 2H), 2.43 (d, J = 7.60 Hz, 1H), 2.38 (d, J = 7.47 Hz, 1H), 2.09-1.29 (m, 10H).
+
LC-MS (m/z): 345 [M+H] .
5.2.25.E-and Z-[5-(4-{2-[(Naphthalene-2-carbonyl)amino]ethylcarbamoyl}phenoxy)adamantan-
2
-yl]acetic acid (27b)
A mixture of E- and Z-4-(4-methoxycarbonylmethyladamantan-1-yloxy)benzoic acid 25 (40 mg,
.116 mmol), EDCI (55.66 mg, 0.290 mmol), naphthalene-2-carboxylic acid (2-amino-ethyl)-
0
amide hydrochloride 17b (32.03 mg, 0.128 mmol), HOBt (23.54 mg, 0.174 mmol) and hünig's
base (52.66 mg, 0.407 mmol) in dichloromethane (8 mL) was stirred for 24 h. The reaction
3
mixture was diluted with aqueous NaHCO and extracted with dichloromethane. The extracts
were washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo. The
residue was purified by silica gel column chromatography to give E- and Z-[5-(4-{2-
[(naphthalene-2-carbonyl)amino]ethylcarbamoyl}phenoxy)adamantan-2-yl]-acetic acid methyl
ester 26b (54 mg, 86 %).
To a solution of 26b (54 mg, 0.1 mmol) in THF /water (20 mL, 3:1) was added NaOH (16 mg,
0
.4 mmol). The reaction mixture was stirred at room temperature for 16 h. The THF was
removed in vacuo and resulting solution was acidified with 1N hydrochloric acid to pH 2-3.
More water was added (100 mL) and the aqueous solution was extracted with EtOAc (3 x 50
mL). The combined organic layer was washed with brine, dried over sodium sulfate and
concentrated. A crude product was isolated form acetonitrile to afford E- and Z-[5-(4-{2-
[(naphthalene-2-carbonyl)amino]ethylcarbamoyl}phenoxy)adamantan-2-yl]acetic acid 27b (49
1
mg, 93%) as a white solid. H NMR (300 MHz, DMSO-d
6
):
δ

12.05 (s, 1H), 8.79-8.74 (m,
1
H), 8.57-8.51 (m,1H), 8.44 (s, 1H), 8.03-7.91 (m, 4H), 7.82-7.77 (m, 2H), 7.63-7.56 (m, 2H),

ACCEPTED MANUSCRIPT
7
.03 (dd, J = 8.37, 1.67 Hz, 2H), 3.52-3.43 (m, 4H), 2.33 (d, J = 7.52 Hz, 1H), 2.26 (d, J= 7.30
Hz, 1H), 2.14-1.84 (m, 6H), 1.82-1.77 (m, 2H), 1.71 (d, J = 12.82 Hz, 1H), 1.65-1.57 (m, 4H),
+
-1
1
1
.33 (d, J =12.58 Hz, 1H); LC-MS (m/z): 527 [M+H] ; IR (ATR) ν max cm : 3280, 2914, 2859,
706, 1627, 1546, 1498, 1294, 1226, 1173, 860, 680; Anal. Calcd for C32 : C,72.98;
34 2 5
H N O
H,6.51; N,5.32. Found: C,72.66; H,6.47; N,5.30.
5.2.26. E-and Z-[5-(4-{2-[(Biphenyl-4-carbonyl)amino]ethylcarbamoyl}phenoxy)adamantan-2-
yl]-acetic acid (27c)
Using the procedure for 27b with biphenyl-4-carboxylic acid (2-aminoethyl)amide hydrochloride
1
7c and E- and Z-4-(4-methoxycarbonylmethyladamantan-1-yloxy)benzoic acid 25 provided the
1
title compound as a white solid (56 mg, 84%). H NMR (500 MHz, DMSO-d ):
δ

12.08 (s,
6
1
7
H), 8.68-8.62 (m, 1H), 8.55-8.49 (m,1H), 7.94 (d, J = 8.32 Hz, 2H), 7.81-7.70 (m, 6H), 7.51-
.46 (m, 2H), 7.42-7.38 (m, 1H), 7.03 (dd, J = 8.53, 1.58 Hz, 2H), 3.48-3.42 (m, 4H), 2.33 (d, J
=
7.52 Hz, 1H), 2.26 (d, J = 7.30 Hz, 1H), 2.14-1.83 (m, 7H), 1.82-1.77 (m, 2H), 1.71 (d, J =
+
1
2.93 Hz, 1H), 1.66-1.57 (m, 3H), 1.33 (d, J =12.93 Hz, 1H); LC-MS (m/z): 553 [M+H] ; IR
-1
(
ATR) ν max cm : 3319, 2915, 2859, 1701,1699, 1630, 1534, 1498, 1223, 1067, 753, 697; Anal.
Calcd for C34 : C,73.89; H,6.57; N,5.07. Found: C,73.72; H,6.59; N,4.98.
36 2 5
H N O
5.2.27. Naphthalene-2-carboxylic acid (3-aminopropyl)amide hydrochloride (30b)
A mixture of naphthalene-2-carboxylic acid 15b (150 mg, 0.871 mmol), EDCI (417.51 mg,
.178 mmol), (3-aminopropyl)carbamic acid tert-butyl ester 28 (159.39 mg, 0.915 mmol), HOBt
176.58 mg, 1.307 mmol) and hünig's base (395.02 mg, 3.049 mmol) in dichloromethane (10
2
(
mL) was stirred for 2 days. The reaction mixture was diluted with aqueous NaHCO and
3
extracted with dichloromethane. The extracts were washed with brine, dried over anhydrous

ACCEPTED MANUSCRIPT
sodium sulfate and concentrated in vacuum. The residue was purified by silica gel column
chromatography to give {3-[(naphthalene-2-carbonyl)amino]propyl}carbamic acid tert-butyl
ester 29b.
To a mixture of {3-[(naphthalene-2-carbonyl)amino]propyl}carbamic acid tert-butyl ester 29b
in ethyl acetate (7 mL) was added hydrogen chloride 4.0 M solution in 1,4-dioxane (1 mL) and
the mixture was stirred for 12 h. The mixture was concentrated to minimum volume and the
residue was collected by filtration to obtained naphthalene-2-carboxylic acid (3-amino-propyl)-
amide hydrochloride 30b (181 mg, 78%, over two steps) as a white solid. Product was used for
1
next step without further purification. H NMR (300 MHz, DMSO-d ):
δ

8.92 (t, J = 5.66 Hz,
6
1
7
H), 8.49 (s, 1H), 8.07-7.93 (m, 7H), 7.65-7.55 (m, 2H), 3.39 (q, J = 5.88 Hz, 2H), 2.86 (t, J =
+
.18 Hz, 2H), 1.93-1.80 (m, 2H); LC-MS (m/z): 229 [M+H] .
The following compound 30c was prepared from the corresponding starting materials in a
similar manner to that described for 30b.
5.2.28. Biphenyl-4-carboxylic acid (3-aminopropyl)amide hydrochloride (30c)
Using the procedure for 30b with biphenyl-4-carboxylic acid 15c provided the title compound as
1
a white solid (179 mg, 76%, over two steps). H NMR (300 MHz, DMSO-d ):
δ

8.79 (t, J =
6
5
.65 Hz, 1H), 8.03-7.89 (m, 5H), 7.81-7.69 (m, 4H), 7.53-7.36 (m, 3H), 3.41-3.30 (m, 2H), 2.84
+
(
t, J = 7.48 Hz, 2H), 1.91-1.77 (m, 2H); LC-MS (m/z): 255 [M+H] .
5.2.29.
E- and
Z-4-(4-{3-[(Naphthalene-2-carbonyl)amino]propylcarbamoyl}phenoxy)-
adamantane-1-carboxylic acid (32b)

ACCEPTED MANUSCRIPT
A mixture of E- and Z-4-(4-carboxyphenoxy)adamantane-1-carboxylic acid methyl ester 5 (40
mg, 0.116 mmol), EDCI (58.02 mg, 0.303 mmol), naphthalene-2-carboxylic acid (3-amino-
propyl)amide hydrochloride 30b (35.26 mg, 0.133 mmol), HOBt (24.54 mg, 0.182 mmol) and
hünig's base (54.9 mg, 0.424 mmol) in dichloromethane (8 mL) was stirred for 24 h. The
reaction mixture was diluted with aqueous NaHCO and extracted with dichloromethane. The
3
extracts were washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo.
The residue was purified by silica gel column chromatography to give E- and Z-4-(4-{3-
[(naphthalene-2-carbonyl)amino]propylcarbamoyl}phenoxy)adamantane-1-carboxylic
acid
methyl ester 31b (60 mg, 91 %).
To a solution of 31b (60 mg, 0.111 mmol) in THF /water (20 mL, 3:1) was added NaOH (22.20
mg, 0.555 mmol). The reaction mixture was stirred at room temperature for 16 h. The THF was
removed in vacuo and resulting solution was acidified with 1N hydrochloric acid to pH 2-3.
More water was added (100 mL) and the aqueous solution was extracted with EtOAc (3 x 50
mL). The combined organic layer was washed with brine, dried over sodium sulfate and
concentrated. A crude product was isolated form acetonitrile to afford E-and Z-4-(4-{3-
[(naphthalene-2-carbonyl)amino]propylcarbamoyl}phenoxy)adamantane-1-carboxylic acid 32b
1
(
49 mg, 84%) as a white solid. H NMR (300 MHz, DMSO-d ):
δ

12.07 (s, 1H), 8.67 (t, J =
6
5
.60 Hz, 1H), 8.43 (s, 1H), 8.36 (t, J = 5.45 Hz, 1H), 8.04-7.95 (m, 3H), 7.93 (d d, J = 8.63,1.32
Hz, 1H), 7.80 (d, J = 8.63 Hz, 2H), 7.63-7.56 (m, 2H), 7.05-6.99 (m, 2H), 4.62-4.52 (m, 1H),
+
-1
3
.41-3.33 (m, 4H), 2.21-1.40 (m, 15H); LC-MS (m/z): 527 [M+H] ; IR (ATR) ν max cm : 3337,
2
920, 2857, 1686, 1625, 1640, 1501, 1293, 1236, 1185, 1025, 766; Anal. Calcd for C H N O :
3
2
34
2
5
C,72.98; H,6.51; N,5.32. Found: C,73.11; H,6.72; N,4.99.