Synthesis and biological evaluation of triazepane derivatives as DPP-IV inhibitors

Article abstract of DOI:10.1016/j.jfluchem.2009.08.001

A series of triazepane derivatives such as (R)-3-amino-1-(1,2,5-triazepan-1-yl)-4-(2,4,5-trifluorophenyl)butan-1-ones (7, 13a-p) and (R)-3-amino-1-(1,2,5-triazepan-5-yl)-4-(2,4,5-trifluorophenyl)butan-1-ones (17a-e) was synthesized and evaluated for their

Full text of DOI:10.1016/j.jfluchem.2009.08.001

Journal of Fluorine Chemistry 130 (2009) 1001–1010
Contents lists available at ScienceDirect
Journal of Fluorine Chemistry
journal homepage: www.elsevier.com/locate/fluor
Synthesis and biological evaluation of triazepane derivatives as DPP-IV inhibitors
Woul Seong Park a, Mi Ae Jun b, Mi Sik Shin b, Sung Wook Kwon b, Seung Kyu Kang b, Ki Young Kim b,
Sang Dal Rhee b, Myung Ae Bae b, Banda Narsaiah b, Duck Hyung Lee a, Hyae Gyeong Cheon b,
b,
Jin Hee Ahn b, , Sung Soo Kim
*
*
a Department of Chemistry, Sogang University, Seoul 121-742, Republic of Korea
b Drug Discovery Division, Korea Research Institute of Chemical Technology, Yuseong-Gu, Daejeon 305-600, Republic of Korea
A R T I C L E I N F O
A B S T R A C T
Article history:
A series of triazepane derivatives such as (R)-3-amino-1-(1,2,5-triazepan-1-yl)-4-(2,4,5-trifluorophe-
nyl)butan-1-ones (7, 13a–p) and (R)-3-amino-1-(1,2,5-triazepan-5-yl)-4-(2,4,5-trifluorophenyl)butan-
1-ones (17a–e) was synthesized and evaluated for their ability to inhibit dipeptidyl peptidase IV (DPP-
IV) enzyme. Compounds with the acid moiety were found to be potent inhibitors of DPP-IV without
inhibiting CYP 3A4. Among them, compound 13p ((R)-4-[1-acetyl-2-{3-amino-4-(2,4,5-trifluorophe-
Received 22 October 2008
Received in revised form 31 July 2009
Accepted 1 August 2009
Available online 8 August 2009
nyl)butanoyl-1,2,5-triazepan-5-carbonyl}benzoic acid]) showed
inhibiting CYP.
a good in vitro activity without
Keywords:
Dipeptidyl peptidase IV
Incretin
ß 2009 Elsevier B.V. All rights reserved.
Diabetes
Triazepane
1. Introduction
biological properties of the molecule. The fluorine substitution is
extensively practiced in the design of potential molecules and
Diabetes mellitus (type 2) is a non-insulin dependent disease
caused by chronic hyperglycemia, and considered under multi-
ple metabolic disorders. It is commonly observed in patients
with inadequate insulin secretion, insulin resistance, hepatic
glucose overproduction or glucose intolerance [1]. Incretin, a
glucagon-like peptide hormone (GLP-1) [2,3] is released from L
cells of the small intestine in response to the digestion of food,
and plays an important role in insulin secretion. Increased
activity of incretin will lead to sustained insulin secretion, which
regulates the glucose level in the body. It also controls gastric
emptying, induction of satiety as well as regeneration and
therefore there is a growing demand for the synthesis of
fluorinated molecules. Recently, several studies have emerged
on the use of fluorinated molecules [14–20] as DPP-IV inhibitors,
some of which are in advanced stage of development. Among them,
MK-0431 (Sitagliptin, launched in the market by Merck) is a
representative fluorinated DPP-IV inhibitor and its 2,4,5-trifluor-
ophenyl moiety occupy the active pocket of DPP-IV [14].
We have been working on finding new molecules which can
selectively inhibit DPP-IV without inhibiting cytochrome P450
(CYP) enzymes which play a major role in metabolizing drug
molecules. Many lead candidate molecules in pharmaceutical
development fail due to inhibition of one or more isozyme forms of
CYP enzymes. CYP 3A4, is one of the most important cytochrome
P450s present in human liver [21] has ability to metabolize >50%
of administered therapeutic agents. It accounts for the large
number of documented drug–drug interactions associated with
CYP 3A4 inhibition [22–24].
Our continued efforts [25–27] towards finding a potential
dipeptidyl peptidase IV (DPP-IV) inhibitor, we designed triazepane
derivatives having (R)-3-amino-4-(2,4,5-trifluorophenyl)butanoyl
moiety which was conceived from MK-0431. Thus, we wish to
report here the synthesis of triazepane derivatives and biological
evaluation for their ability to inhibit dipeptidyl peptidase IV (DPP-
IV) without inhibiting CYP. MK-0431 was used as a reference. The
basic skeletons are outlined below.
differentiation of islet
b-cells [4,5]. Dipeptidyl peptidase IV
(DPP-IV), a serine protease present in many tissues and body
fluids, existing either in the membrane bound or soluble enzyme
form, degrades GLP-1 (GLP-1[7–36]amide) into inactive GLP[9–
36]amide [6–8] at the N-terminus position. Inhibition of DPP-IV
increases the concentration of GLP-1 and, as a result, increases
insulin secretion [9–11], which can ameliorate hyperglycemia in
type 2 diabetes.
It is known that fluorine or trifluoromethyl [12,13] group at an
appropriate position in the molecule alters the chemical and
* Corresponding author. Fax: +82 42 860 7160.
E-mail address: jhahn@krict.re.kr (J.H. Ahn).
0022-1139/$ – see front matter ß 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.jfluchem.2009.08.001

1002
W.S. Park et al. / Journal of Fluorine Chemistry 130 (2009) 1001–1010
(R)-3-amino-1-(1,2,5-triazepan-1-yl)-4-(2,4,5-trifluorophenyl)butan-1-one (7, 13a–p) and (R)-3-amino-1-(1,2,5-triazepan-5-yl)-4-(2,4,5-
trifluorophenyl)butan-1-one (17a–e) derivatives.
(R)-3-amino-1-(3-(trifluoromethyl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-yl-4-(2,4,5-trifluorophenyl)butan-1-one (MK-0431)
[14].
Scheme 1. Synthesis of (R)-3-amino-1-(1,2,5-triazepan-1-yl)-4-(2,4,5-trifluorophenyl)butan-1-one (7,13a–p) derivatives
Reagents and conditions: (a) CbzCl, Na2CO3, acetone/H2O, 0 8C to room temperature; (b) BocNHNHBoc, 50% NaOH, Et4NBr, toluene, reflux, 12 h; (c) 4 M HCl, ethyl acetate,
12 h; (d) (R)-3-BocNH-4-(2,4,5-trifluorophenyl)butanoic acid, EDCI, Et3N, CH2Cl2, room temperature, 12 h; (e) 10% Pd/C, H2 balloon, MeOH, room temperature; (f) electrophile
(acid or acyl halide), EDCI, Et3N, CH2Cl2, room temperature.

W.S. Park et al. / Journal of Fluorine Chemistry 130 (2009) 1001–1010
1003
Scheme 2. Synthesis of (R)-3-amino-1-(1,2,5-triazepan-5-yl)-4-(2,4,5-trifluorophenyl)butan-1-one (17a–e)derivatives.
Reagents and conditions: (a) Electrophile (acid halide); (b) 10% Pd/C, H2 balloon, MeOH, room temperature, 12 h; (c) (R)-3-BocNH-4-(2,4,5-trifluorophenyl)butanoic acid,
EDCI, Et3N, CH2Cl2, room temperature, 12 h; (d) 4 M HCl, ethyl acetate, room temperature, 12 h.
Table 1
In vitro DPP-IV inhibitory activity of (R)-3-amino-1-(1,2,5-triazepan-1-yl)-4-(2,4,5-trifluorophenyl)butan-1-one (7, 13a–l) derivatives.
Compound
Ra
H
Rb
H
IC50 (nM)a
9800
7
13a
H
859
13b
13c
578
1200
13d
13e
13f
H
H
H
2500
2900
681
13g
H
609

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W.S. Park et al. / Journal of Fluorine Chemistry 130 (2009) 1001–1010
Table 1 (Continued )
Compound
Ra
Rb
IC50 (nM)a
13h
1800
13i
13j
700
401
13k
591
13l
151
101
MK-0431
a
The IC50 values were determined by a direct regression curve analysis.
Table 2
In vitro DPP-IV inhibitory activity of (R)-3-amino-1-(1,2,5-triazepan-5-yl)-4-(2,4,5-trifluorophenyl)butan-1-one (17a–e) derivatives.
Compound
Ra
H
Rb
H
IC50 (nM)a
4500
17a
17b
17c
17d
H
3300
1600
660

W.S. Park et al. / Journal of Fluorine Chemistry 130 (2009) 1001–1010
1005
Table 2 (Continued )
Compound
17e
Ra
Rb
IC50 (nM)a
853
MK-0431
101
a
The IC50 values were determined from a direct regression curve analysis.
2. Results and discussion
further coupled with (R)-3-[(tert-butoxycarbonyl)amino]-4-
(2,4,5-trifluorophenyl)butanoic acid in the presence of EDCI to
give compound 5. Compound 5 was then reduced using 10%
palladium on carbon under hydrogen atmosphere to yield
compound 6, followed by Boc deprotection with 4 M HCl to
obtain compound 7. Also, compound 5 was deprotected or
further derivatized by acylating reagents to give compound 13.
Alternatively, compound 8 was reacted with various electro-
philes, then Boc deprotection, followed by reaction with (R)-3-
[(tert-butoxycarbonyl)amino]-4-(2,4,5-trifluorophenyl)butanoic
acid to give compound 11 through compounds 9 and 10.
Compound 11 was further converted to final compounds 13 via
compound 12 or directly.
2.1. Synthesis
The triazepane derivatives
7 and 13 were synthesized
according to Scheme 1. Bis(2-chloroethyl)amine 1 was initially
protected with benzyl chloroformate (CbzCl) in the presence of a
base, and coupled with di-tert-butyl hydrazine-1,2-dicarbox-
ylate to yield cyclic triazepane 3. Two strategies were adopted
for selective deprotection of compound 3. One strategy was Boc
deprotection using 4 M HCl and another was Cbz deprotection
using 10% palladium on carbon under hydrogen atmosphere to
obtain compounds 4 and 8, respectively. Compound 4 was
Table 3
In vitro DPP-IV and CYP 3A4 inhibitory activity of (R)-3-amino-1-(1,2,5-triazepan-1-yl)-4-(2,4,5-trifluorophenyl)butan-1-one (13m–p)derivatives.
Compound
Ra
H
Rb
IC50 (nM)a
439
CYP 3A4 activity at 10
NT
mM (%)
13m
13n
13o
13p
H
216
213
98
92.4
NT
87.2
MK-0431
101
a
The IC50 values were determined from a direct regression curve analysis.

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W.S. Park et al. / Journal of Fluorine Chemistry 130 (2009) 1001–1010
Table 4
4. Experimental
Selectivity of compounds 13n and p toward DPP-IV-related enzymes.
DPP-IV IC50 (nM)a
DPP-2 (nM)
DPP-8 (nM)
4.1. General
Compound
13n
13p
216
98
37,153
77,624
24,547
29,512
All reported yields are isolated yields after column chromato-
graphy or crystallization. The 1H NMR spectra were recorded on
FT-NMR Varian GEMINI-200FT or Bruker AVANCE-300 and TMS as
an internal reference. ATR-FTIR spectra were recorded on Travel IR
(Sens IR Technology) spectrophotometer. Low-resolution mass
spectra were obtained on the Liquid Chromatography-Mass
Spectrometer (LC-MS, Waters). High-resolution mass spectra were
obtained on the Autospec magnetic sector mass spectrometer
(Micromass, Manchester, UK).
a
The IC50 values were determined from a direct regression curve analysis.
Similarly, triazepane derivatives 17 were synthesized as shown
in Scheme 2. Thus, compound 4 was acylated with various
acylating reagents to afford compound 14, and on Cbz deprotection
gave compound 15 followed by coupling with (R)-3-[(tert-
butoxycarbonyl)amino]-4-(2,4,5-trifluorophenyl)butanoic
resulted compound 16. Alternatively, compound 16a was prepared
starting from compound 8 through coupling with (R)-3-[(tert-
acid
butoxycarbonyl)amino]-4-(2,4,5-trifluorophenyl)butanoic
acid
4.1.1. Preparation of benzyl bis(2-chloroethyl)carbamate (2)
followed by Boc deprotection yielded compound 17.
To a solution of bis-(2-chloroethyl)amine HCl 1 (4.5 g,
25.2 mmol) in acetone/H2O (100 mL, 1:1), were added Na2CO3
(8.9 g, 84.0 mmol) and benzyl chloroformate (4.7 mL, 33.6 mmol)
at 0 8C. The reaction mixture was stirred for 1 h at room
temperature. Acetone was removed under vacuum, and aqueous
residue was extracted with ethyl acetate. Organic layer was
washed with brine, dried over MgSO4, and concentrated. The
residue was purified by silica gel column chromatography (ethyl
acetate/hexane: 1/9) to give compound 2 (5.3 g, 61%, colorless oil)
2.2. In vitro DPP-IV inhibitory activity
The 1-[3-amino-4-(2,4,5-trifluorophenyl)butanoyl]triazepane
derivatives (7 and 13a–l) were evaluated in vitro for their DPP-IV
inhibition and the results are summarized in Table 1. MK0431 was
used as a reference compound. The basic compound (7, Ra = Rb = H)
showed weak inhibitory activity with an IC50 value of 9.8
mM.
Introduction of the benzyloxycarbonyl group at the Rb position
resulted in improved potency (13a, Ra = H, Rb = Cbz, IC50 = 859 nM).
Furthermore, acetyl derivative at the Ra position (13b, Ra = CH3CO,
Rb = Cbz) showed better inhibitory activity with an IC50 value of
578 nM. Whereas the benzoyl substituent (13c, Ra = C6H5CO,
Rb = Cbz) reduced the activity. The 5-pyrazine, 5-methyl acetate
and 2-acetyl-5-methanesulfonyl derivatives showed micromolar
range potencies (13d, e, h). However, the 5-trifluoroacetyl, 5-
methanesulfonyl and 2,5-disubstituted derivatives showed better
potencies (13f, g, i–l) with the IC50 values in the 151–700 nM range.
Among all of the derivatives, compound 13l (Ra = 2-(thiazolo[5,4-
b]pyridine-2-ylthio)acetyl, Rb = CH3SO2) demonstrated the highest
in vitro activity, with an IC50 value of 151 nM.
1H NMR (CDCl3, 300 MHz):
d 7.36–7.35 (m, 5H), 5.15 (s, 2H), 3.69–
3.65 (m, 4H), 3.61–3.55 (m, 4H); LC-MS: m/z 276 (MH+).
4.1.2. Preparation of 5-benzyl-1,2-di-tert-butyl-1,2,5-triazepane-
1,2,5-tricarboxylate (3)
To a solution of benzyl bis-(2-chloroethyl)carbamate 2 (4.2 g,
18.1 mmol) and di-t-butyl hydrazodiformate (5.0 g, 18.1 mmol) in
toluene (36 mL), were added 50% NaOH solution (18 mL) and
tetraethyl ammonium bromide (570 mg, 2.7 mmol). The mixture
was stirred for 13 h under reflux condition, cooled to room
temperature, and then extracted with ethyl acetate. The organic
layer was washed with brine, dried over MgSO4, and concentrated.
The residue was purified by silica gel column chromatography
(ethyl acetate/hexane: 1/1) to give compound 3 (4.0 g, 51%,
The 5-[3-amino-4-(2,4,5-trifluorophenyl)butanoyl]triazepane
derivatives (17a–e) also were evaluated in vitro, and the results
are summarized in Table 2. The basic triazepane derivative 17a
(Ra = Rb = H) showed a weak inhibitory activity with an IC50 of
colorless oil). 1H NMR (CDCl3, 200 MHz):
d 7.36–7.34 (m, 5H), 5.14
(s, 2H), 4.21–4.02 (m, 2H), 3.98–3.65 (m, 1H), 3.52–3.04 (m, 5H),
1.49 (s, 18H); LC-MS: m/z 436 (MH+); IR 2975, 2932, 1692, 1721.
4.5
mM and the introduction of substituents for Ra and Rb (17b–e)
resulted an improved activity with the IC50 values in the 853–
3300 nM range.
4.1.3. Preparation of benzyl-1,2,5-triazepane-5-carboxylateꢀ2HCl (4)
To a solution of 5-benzyl-1,2-di-tert-butyl-1,2,5-triazepane-
1,2,5-tricarboxylate 3 (1.3 g, 2.99 mmol) in ethyl acetate (5 mL),
was added 4M-HCl/1,4-dioxane (5 mL). The reaction mixture was
stirred for 16 h at room temperature, and then the solvents were
evaporated. The residue was crystallized with ether to give
compound 4 (400 mg, 43%, white solid). m.p. 91–94 8C; 1H NMR
Based on the inhibitory activity data of the above two series of
compounds, compound 13 derivatives were found to be promising,
and therefore we further derivatized to find more potent
compounds. Thus, a new set of triazepane derivatives was
synthesized, evaluated for their inhibitory activity and CYP
inhibition. Compounds with an acid moiety were found to exhibit
good DPP-IV inhibitory activity without inhibiting CYP as shown in
Table 3. The compound 13p showed promising in vitro DPP-IV
inhibitory activity with an IC50 value of 98 nM without CYP 3A4
(DMSO-d6, 300 MHz):
d 7.37 (m, 5H), 5.09 (s, 2H), 4.20–3.00 (m,
8H); LC-MS: m/z 236 (MH+); IR 2974, 2931, 1691.
4.1.4. Preparation of (R)-benzyl-1-(3-(tert-butoxycarbonylamino)-4-
(2,4,5-trifluorophenyl)butanoyl)-1,2,5-triazepane-5-carboxylate (5)
To a solution of (R)-3-(tert-butoxycarbonylamino)-4-(2,4,5-
trifluorophenyl)butanoic acid (333 mg, 1.00 mmol) in CH2Cl2
(5 mL), were added 1-(3-dimethylaminopropyl)-3-ethylcarbodii-
mide hydrochloride (EDCI, 552 mg, 1.92 mmol), TEA (1.39 mL,
inhibition at 10
mM concentration. We also examined the
selectivity toward DPP-IV-related enzymes such as DPP-2 and
DPP-8 (Table 4). Compound 13p displayed at least 300-fold better
selectivity toward DPP-IV related enzymes.
3. Conclusion
10 mmol) and 5-benzyl-1,2,5-triazepane-5-carboxylateꢀ2HCl
4
(369 mg, 1.20 mmol). The reaction mixture was stirred for 12 h
at room temperature. Organic layer was extracted from H2O/
CH2Cl2 and washed with brine, dried over MgSO4, and evaporated.
The residue was purified by silica gel column chromatography
(ethyl acetate/hexane: 2/1) to obtain compound 5 (440 mg, 80%,
A series of triazepane derivatives (7, 13a–p and 17a–e) was
synthesized, and evaluated their ability to inhibit the dipeptidyl
peptidase IV (DPP-IV). Compound 13p showed a good in vitro
activity, selectivity without CYP inhibition. Further studies are
underway to optimize this compound class for use in the treatment
of diabetes.
colorless oil). 1H NMR (CDCl3, 200 MHz):
7.12–6.99 (m, 1H), 6.88–6.81 (m, 1H), 5.48–5.32 (br, 1H), 5.12 (s,
d 7.35–7.32 (m, 5H),

W.S. Park et al. / Journal of Fluorine Chemistry 130 (2009) 1001–1010
1007
2H), 4.14–4.10 (m, 1H), 3.73–3.46 (m, 8H), 3.00–2.70 (m, 4H), 1.36
acetate (18 mL), was added 4 M-HCl/1,4-dioxane (18 mL) and the
mixture was stirred for 12 h at room temperature. The solvents
were evaporated, the residue was crystallized with ether to yield
(s, 9H); LC-MS: m/z 551 (MH+); IR 2905, 2845, 1691.
4.1.5. Preparation of (R)-tert-butyl-4-oxo-4-(1,2,5-triazepan-1-yl)-
1-(2,4,5-trifluorophenyl)butan-2-ylcarbamate (6)
10m (1.32 g, 79%). 1H NMR (MeOH-d4, 300 MHz):
d 8.04–7.97 (m,
2H), 7.58–7.49 (m, 2H), 4.08–3.94 (m, 2H), 3.83 (s, 3H), 3.56–3.36
(m, 4H), 3.29–3.06 (m, 2H); LC-MS: m/z 264 (MH+). IR 2977, 1662.
To a solution of (R)-benzyl 1-(3-(tert-butoxycarbonylamino)-4-
(2,4,5-trifluorophenyl)butanoyl)-1,2,5-triazepane-5-carboxylate 5
(35 mg, 0.064 mmol) in methanol (2 mL), was added 10%-Pd/C
(7 mg, 20 mol%). The reaction mixture was stirred for 10 h in
hydrogen atmosphere, filtered through celite, washed with
additional methanol and concentrated. The residue was purified
by silica gel column chromatography (ethyl acetate/MeOH: 2/1) to
give compound 6 (24 mg, 90%). m.p. 76–78 8C; 1H NMR (CDCl3,
4.2.3. (R)-Methyl-4-(1-(3-(tert-butoxycarbonylamino)-4-(2,4,5-
trifluorophenyl)butanoyl)-1,2,5-triazepane-5-carbonyl)benzoate
(11m)
To a solution of (R)-3-(tert-butoxycarbonylamino)-4-(2,4,5-
trifluorophenyl)butanoic acid (320 mg, 0.96 mmol) in CH2Cl2,
were added 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide
hydrochloride (EDCI, 552 mg, 1.92 mmol), TEA (1.34 mL,
9.6 mmol) and 4-(1,2,5-triazepane-5-carbonyl)benzoate dihy-
drochloride 10m (643 mg, 1.92 mmol). The reaction mixture
was stirred for 12 h at room temperature. Organic layer was
extracted from H2O/CH2Cl2 and washed with brine, dried over
MgSO4, and evaporated. The residue was purified by silica gel
column chromatography (ethyl acetate/hexane: 1/1) to obtain
200 MHz):
d 7.03–6.82 (m, 1H), 6.79–6.60 (m, 1H), 5.60–5.47 (br,
1H), 4.21–3.83 (m, 2H), 3.31–3.03 (m, 3H), 2.86–2.53 (m, 4H),
2.29–2.11 (m, 4H), 1.22 (s, 9H); LC-MS: m/z 417 (MH+).
4.1.6. Preparation of (R)-3-amino-1-(1,2,5-triazepan-1-yl)-4-(2,4,5-
trifluorophenyl)butan-1-oneꢀHCl (7)
To a solution of [(R)-tert-butyl-4-oxo-4-(1,2,5-triazepan-1-yl)-1-
(2,4,5-trifluorophenyl)butan-2-ylcarbamate]6 (18 mg, 0.043 mmol)
in ethyl acetate (1 mL), was added 4 M-HCl/1,4-dioxane (1 mL) and
the mixture was stirred for 16 h at room temperature. The solvents
were evaporated, and the residue was crystallized with ether to give
compound 7 (12 mg, 80%, white solid). m.p. 115–117 8C; 1H NMR
11m (250 mg, 45%). 1H NMR (CDCl3, 300 MHz):
d 8.10–8.08 (m,
2H), 7.45–7.39 (m, 2H), 7.11–7.06 (m, 1H), 6.92–6.89 (m, 1H), 5.48
(br, 1H), 4.30–4.18 (m, 1H), 3.99 (s, 3H), 3.94–3.77 (m, 3H), 3.69–
3.43 (m, 4H), 3.30–3.18 (m, 1H), 3.08–2.87 (m, 4H), 2.84–2.76 (m,
1H), 1.37 (s, 9H); LC-MS: m/z 579 (MH+); IR 2846, 1660, 1630.
(DMSO-d6, 300 MHz):
d 11.13 (br, 1H), 9.94, 9.08 (br, 1H), 8.00 (br,
2H), 7.37–7.34 (m, 2H), 4.61–4.35 (m, 1H), 4.17–4.14 (m, 1H), 3.94–
3.89 (m, 1H), 3.76–3.14 (m, 5H), 2.79–2.76 (m, 2H), 2.60–2.53 (m,
3H); LC-MS: m/z 317 (MH+); IR 3423, 2840, 1631.
4.2.4. Preparation of (R)-methyl-4-(1-(3-amino-4-(2,4,5-
trifluorophenyl)butanoyl)-1,2,5-triazepane-5-carbonyl)benzoateꢀHCl
(13m)
To a solution of (R)-methyl-4-(1-(3-(tert-butoxycarbonyla-
mino)-4-(2,4,5-trifluorophenyl)butanoyl)-1,2,5-triazepane-5-car-
bonyl)benzoate 11m (30 mg, 0.052 mmol) in ethyl acetate (2 mL),
was added 4 M HCl/1,4-dioxane (2 mL) and the mixture was stirred
for 12 h at room temperature. The solvents were evaporated, and
the residue was crystallized with ether to give compound 13m
(20 mg, 76%, white solid). m.p. 158–160 8C; 1H NMR (DMSO-d6,
4.1.7. Preparation of [1,2,5]triazepane-1,2-dicarboxylic acid di-tert-
butyl ester (8)
To a solution of 5-benzyl 1,2-di-tert-butyl-1,2,5-triazepane-
1,2,5-tricarboxylate 3 (1.0 g, 2.30 mmol) in methanol (5 mL), added
10% Pd/C (200 mg, 20 mol%). The reaction mixture was stirred for
10 h under hydrogen atmosphere, filtered through celite, washed
with additional methanol and concentrated. The residue was
purified by silica gel column chromatography (ethyl acetate/MeOH:
9/1) to give compound 8 (1.1 g, 79%, yellow oil). 1H NMR (CDCl3,
300 MHz):
3H), 3.70–3.33 (m, 7H), 3.30–3.28 (m, 2H), 3.15–2.66 (m, 5H);
HRMS (free base, 23H25F3N4O4): calcd., 478.1828; found,
d 8.06 (br, 3H), 7.93 (m, 2H), 7.47–7.45 (m, 4H), 3.81 (s,
C
300 MHz):
d
4.02–3.93 (m, 2H), 3.16–2.98 (m, 3H), 2.85–2.75 (m,
478.1837; IR 3432, 2925, 1677, 1631.
3H), 1.49 (s, 18H); LC-MS: m/z 302 (MH+); IR 2975, 2933, 1697.
4.2.5. Preparation of (R)-4-(1-(3-amino-4-(2,4,5-
4.2. General procedure for the synthesis of compound 13 (Example:
13m and n)
trifluorophenyl)butanoyl)-1,2,5-triazepane-5-carbonyl)benzoic
acidꢀHCl (13n)
To a solution of (R)-methyl-4-(1-(3-(tert-butoxycarbonyla-
mino)-4-(2,4,5-trifluorophenyl)butanoyl)-1,2,5-triazepane-5-
carbonyl)benzoate 11m (50 mg, 0.087 mmol) in THF (2 mL) and
MeOH (2 mL), was added LiOHꢀH2O (10.5 mg, 0.174 mmol in
1 mL water). The reaction mixture was stirred for 12 h at room
temperature, and then acidified by 1 N HCl to adjust around pH
4. The reaction mixture was diluted with brine and ethyl acetate.
The organic layer was separated, dried and evaporated. The
residue was purified by silica gel column chromatography
(ethyl acetate/MeOH: 9/1) to give (R)-4-(1-(3-(tert-butoxycar-
bonylamino)-4-(2,4,5-trifluoro phenyl)butanoyl)-2,5-dihydro-
1H-1,2,5-triazepane-5-carbonyl)benzoic acid (45 mg, 92%,) 1H
4.2.1. Preparation of di-tert-butyl-5-(4-(methoxycarbonyl)benzoyl)-
1,2,5-triazepane-1,2-dicarboxylate (9m)
To
a solution of 4-(methoxycarbonyl)benzoic acid (1 g,
5.55 mmol) in CH2Cl2, were added 1-(3-dimethylaminopropyl)-
3-ethylcarbodiimide hydrochloride (EDCI, 2.13 g, 11.1 mmol),
DMAP (340 mg, 2.77 mmol), di-tert-butyl-1,2,5-triazepane-1,2-
dicarboxylate 8 (2 g, 6.66 mmol) and TEA (3.87 mL, 27.75 mmol).
The reaction mixture was stirred for 4 h at room temperature.
Organic layer was extracted from H2O/CH2Cl2 and washed with
brine, dried over MgSO4, and evaporated. The residue was purified
by silica gel column chromatography (ethyl acetate/hexane: 1/1)
to obtain compound 9m (2.45 g, 95%). 1H NMR (CDCl3, 300 MHz):
d
NMR (CDCl3, 300 M Hz): d 8.08–8.05 (m, 2H), 7.61–7.44 (m, 2H),
8.10 (dd, J = 1.5, 8 Hz, 2H), 7.44–7.40 (m, 2H), 4.27–4.09 (m, 2H),
3.94 (s, 3H), 3.85–3.74 (m, 1H), 3.39–3.14 (m, 4H), 2.97–2.96 (m,
1H), 1.51 (s, 9H), 1.48 (s, 9H); LC-MS: m/z 464 (MH+); IR 2977,
2936, 1697, 1721.
7.15–7.09 (m, 1H), 6.94–6.89 (m, 1H), 5.44 (br, 1H), 4.35–
4.01 (m, 2H), 4.00–3.80 (m, 3H), 3.66–3.44 (m, 4H), 3.30–
3.00 (m, 2H), 2.96–2.80 (m, 4H), 1.37 (s, 9H); LC-MS: m/z 565
(MH+).
To a solution of (R)-4-(1-(3-(tert-butoxycarbonylamino)-4-
(2,4,5-trifluorophenyl)butanoyl)-2,5-dihydro-1H-1,2,5-triaze-
pane-5-carbonyl)benzoic acid (45 mg, 0.080 mmol) in ethyl
acetate (2 mL), was added 4 M-HCl/1,4-dioxane (2 mL) and the
mixture was stirred for 12 h at room temperature. The solvents
4.2.2. Methyl-4-(1,2,5-triazepane-5-carbonyl)benzoate
dihydrochloride (10m)
To a solution of di-tert-butyl-5-(4-(methoxycarbonyl)benzoyl)-
1,2,5-triazepane-1,2-dicarboxylate 9m (2.3 g, 4.9 mmol) in ethyl

1008
W.S. Park et al. / Journal of Fluorine Chemistry 130 (2009) 1001–1010
were evaporated, and the residue was crystallized with ether to
4.2.13. (R)-1-(2-Acetyl-5-(methylsulfonyl)-1,2,5-triazepan-1-yl)-3-
give compound 13n (32 mg, 81% white solid). m.p., 179–182 8C; 1H
amino-4-(2,4,5-trifluorophenyl)butan-1-oneꢀHCl (13h)
NMR (DMSO-d6,300 MHz):
d
8.85 (br, 3H), 7.96–7.80 (m, 2H), 7.52–
1H NMR (DMSO-d6, 300 MHz):
d 8.14 (br, 3H), 7.59–7.58 (m,
7.47 (m, 4H), 4.20–3.56 (m, 10H), 3.39–3.36 (m, 2H), 2.94–2.72 (m,
3H); HRMS calcd. for C22H23F3N4O4: 464.1671; found, 464.1666; IR
3432, 2921, 1679, 1631.
2H), 4.24–4.19 (m, 2H), 3.85–3.78 (m, 1H), 3.60–3.36 (m, 4H),
3.24–3.00 (m, 4H), 2.99 (s, 3H), 2.97–2.76 (m, 1H), 2.23–1.93 (m,
4H); LC-MS: m/z 437 (MH+); IR 3341, 2947, 2888, 1631.
Compound 13a was directly prepared from compound 5 by Boc
deprotection, whereas compounds 13b and c were prepared from
compound 5 via compound 12 in two steps by reaction of
electrophiles like acetyl chloride and benzoyl chloride, respec-
tively, followed by Boc deprotection.
4.2.14. (R)-3-Amino-1-(5-(methylsulfonyl)-2-(2-morpholinoacetyl)-
1,2,5-triazepan-1-yl)-4-(2,4,5-trifluorophenyl)butan-1-oneꢀHCl (13i)
1H NMR (DMSO-d6, 300 MHz):
d 8.45 (br, 3H), 7.68–7.56 (m,
2H), 4.98–4.62 (m, 3H), 4.33–3.82 (m, 7H), 3.64–3.39 (m, 10H),
3.12–2.82 (m, 6H); LC-MS: m/z 522 (MH+); IR 3393, 2932, 2880,
1679, 1634.
4.2.6. (R)-Benzyl-1-(3-amino-4-(2,4,5-trifluorophenyl)butanoyl)-
1,2,5-triazepane-5-carboxylateꢀHCl (13a)
1H NMR (DMSO-d6, 300 MHz):
d
7.96 (br, 3H), 7.55–7.52 (m,
4.2.15. (R)-3-Amino-1-(2-(2-(benzo[d]oxazol-2-ylthio)acetyl)-5-
(methylsulfonyl)-1,2,5-triazepan-1-yl)-4-(2,4,5-
trifluorophenyl)butan-1-oneꢀHCl (13j)
3H), 7.50–7.35 (m, 4H), 5.07 (s, 2H), 3.70–3.65 (m, 4H), 3.56–3.42
(m, 3H), 2.94–2.93 (m, 2H), 2.83–2.77 (m, 4H); LC-MS: m/z 451
(MH+); IR 3420, 2846, 1699, 1683, 1639.
1H NMR (DMSO-d6, 300 MHz):
d 8.20–8.10 (m, 3H), 7.80–7.30
(m, 6H), 4.50–2.80 (m, 18H); LC-MS: m/z 586 (MH+); IR 3441, 2932,
4.2.7. (R)-Benzyl 1-acetyl-2-(3-amino-4-(2,4,5-
2880, 1758, 1665.
trifluorophenyl)butanoyl)-1,2,5-triazepane-5-carbo xylateꢀHCl (13b)
1H NMR (MeOH-d4, 300 MHz):
d
7.54 (m, 2H), 7.36–7.35 (m,
4.2.16. (R)-3-Amino-1-(2-(2-(5-methyl-1,3,4-thiadiazol-2-
ylthio)acetyl)-5-(methylsulfonyl)-1,2,5-triazepan-1-yl)-4-(2,4,5-
trifluorophenyl)butan-1-oneꢀHCl (13k)
5H), 5.09 (s, 2H), 4.26–3.90 (m, 2H), 3.71–3.35 (m, 5H), 3.20–3.10
(m, 1H), 3.05–2.95 (m, 3H), 2.65–2.64 (m, 2H), 2.00 (s, 3H); LC-MS:
m/z 493 (MH+); IR 3449, 2882, 1667, 1631.
1H NMR (DMSO-d6, 300 MHz):
d 8.11 (m, 3H), 7.6–7.50 (m, 2H),
4.55–2.66 (m, 21H); LC-MS: m/z 567 (MH+); IR 3423, 2927, 2862,
4.2.8. (R)-Benzyl 1-(3-amino-4-(2,4,5-trifluorophenyl)butanoyl)-2-
1669.
benzoyl-1,2,5-triazepane-5-carboxylateꢀHCl (13c)
1H NMR (DMSO-d6, 300 MHz):
d
8.15–8.03 (brs, 3H), 7.42–7.02
4.2.17. (R)-3-Amino-1-(5-(methylsulfonyl)-2-(2-(thiazolo[5,4-
b]pyridin-2-ylthio)acetyl)-1,2,5-triazepan-1-yl)-4-(2,4,5-
trifluorophenyl)butan-1-oneꢀHCl (13l)
(m, 12H), 4.91 (s, 2H), 4.38–4.15 (m, 1H), 3.93–3.21 (m, 8H), 3.08–
3.06 (m, 2H), 3.01–2.90 (m, 2H); LC-MS: m/z 555 (MH+); IR 3447,
2941, 1667, 1631.
1H NMR (DMSO-d6, 300 MHz):
d 8.50 (m, 1H), 8.15–7.95 (m,
Compounds 13d–g were prepared from compound
sequence of steps via compounds 9–11 by introducing various
8
in
3H), 7.55–7.25 (m, 3H), 4.40–2.65 (m, 18H); LC-MS: m/z 603
(MH+); IR 3443, 2925, 1671, 1679.
groups on N-5 by known means.
4.2.18. Preparation of (R)-methyl-4-(1-acetyl-2-(3-amino-4-(2,4,5-
trifluorophenyl)butanoyl)-1,2,5-triazepane-5-carbonyl)benzoateꢀHCl
(13o)
4.2.9. (R)-3-Amino-1-(5-(pyrazin-2-yl)-1,2,5-triazepan-1-yl)-4-
(2,4,5-trifluorophenyl)butan-1-oneꢀHCl (13d)
1H NMR (DMSO-d6, 300 MHz):
d
8.56 (s, 1H), 8.31 (br, 1H), 7.81
To a solution of (R)-4-{1-[3-tert-butoxycarbonylamino-4-
(br, 1H), 7.27–7.18 (m, 1H), 7.15–7.06 (m, 1H), 4.11–3.86 (m, 6H),
3.69–3.63 (m, 2H), 2.99–2.94 (m, 6H), 2.78–2.72 (m, 2H); LC-MS:
m/z 395 (MH+); IR 3431, 2912, 1697, 1631.
(2,4,5-trifluorophenyl)butyryl]-[1,2,5]triazepane-5-carbonyl}ben-
zoic acid methyl ester 11m (90 mg, 0.156 mmol) in CH2Cl2, were
added acetyl chloride (22
mL, 0.311 mmol) and TEA (65 mL,
0.467 mmol) at 0 8C. The reaction mixture was stirred for 12 h
at room temperature. Organic layer was extracted from H2O/
CH2Cl2 and washed with brine, dried over MgSO4 and evaporated.
The residue was purified by silica gel column chromatography
(ethyl acetate/MeOH: 7/1) to obtain compound 12o (75 mg, 78%).
4.2.10. (R)-Methyl-2-(1-(3-amino-4-(2,4,5-
trifluorophenyl)butanoyl)-1,2,5-triazepan-5-yl)acetateꢀHCl (13e)
1H NMR (DMSO-d6, 300 MHz):
d 8.23 (brs, 3H), 7.62–7.51 (m,
2H), 4.32 (s, 2H), 3.86–3.26 (m, 11H), 3.00–2.73 (m, 6H); LC-MS: m/
z 389 (MH+); IR 3431, 2910, 1699, 1631.
1H NMR (CDCl3, 300 M Hz):
d 8.12–8.04 (m, 2H), 7.53–7.43 (m, 2H),
7.12–7.03 (m, 1H), 6.93–6.91 (m, 1H), 5.25 (br, 1H), 4.59–4.40 (m,
1H), 4.38–4.29 (m, 1H), 4.26–4.13 (m, 1H), 4.11 (s, 3H), 3.95–3.42
(m, 4H), 3.01–2.94 (m, 3H), 2.64–2.49 (m, 2H), 2.30–1.98 (m, 3H),
1.37 (s, 9H); LC-MS: m/z 621 (MH+); IR 3440, 2922, 2881, 1661,
1631.
4.2.11. (R)-3-Amino-1-(5-(2,2,2-trifluoroacetyl)-1,2,5-triazepan-1-
yl)-4-(2,4,5-trifluorophenyl)butan-1-oneꢀHCl (13f)
1H NMR (DMSO-d6, 300 MHz):
d 8.09 (brs, 3H), 7.54–7.49 (m,
2H), 3.78–3.35 (m, 8H), 2.98–2.92 (m, 4H), 2.81–2.79 (m, 2H); LC-
MS: m/z 413 (MH+); IR 3432, 2927, 2867, 1680, 1633.
To a solution of (R)-4-{1-acetyl-2-[3-tert-butoxycarbonyla-
mino-4-(2,4,5-trifluorophenyl)butyryl]-[1,2,5]triazepane-5-car-
bonyl}benzoic acid methyl ester 12o (25 mg, 0.040 mmol) in
ethyl acetate (1 mL), added 4 M-HCl/1,4-dioxane (1 mL) and
the mixture was stirred for 12 h at room temperature. The
solvents were evaporated, and the residue was crystallized with
ether to give compound 13o (18 mg, 81%, white solid). 169–
4.2.12. (R)-3-Amino-1-(5-(methylsulfonyl)-1,2,5-triazepan-1-yl)-4-
(2,4,5-trifluorophenyl)butan-1-oneꢀHCl (13g)
1H NMR (DMSO-d6, 300 MHz):
d 8.07 (brs, 3H), 7.54–7.46 (m,
2H), 4.01 (br, 1H), 3.63–3.62 (m, 2H), 3.37–3.29 (m, 4H), 3.00–2.93
(m, 4H), 2.90 (s, 3H), 2.88–2.78 (m, 2H); LC-MS: m/z 395 (MH+); IR
3342, 2925, 1631.
171 8C; 1H NMR (DMSO-d6, 300 MHz):
d 8.08 (br, 3H), 7.95
Compounds 13h–l were prepared from compound
8
by
(m, 2H), 7.50–7.47 (m, 4H), 4.21–4.09 (m, 2H), 3.81 (s, 3H),
3.67–3.57 (m, 3H), 3.50 (s, 3H), 3.40–3.00 (m, 3H), 2.95–2.61
(m, 3H), 2.07–1.76 (m, 2H); HRMS (free base, C25H27F3N4O5):
calcd., 520.1934; found, 520.1899; IR 3441, 2923, 2867, 1669,
1631.
primarily fixing methanesulfonyl group on N-5 followed by in
sequence of steps via compounds 9–11. Then, reaction of
compound 11 with various acyl halides to have compound 12
followed by Boc deprotection to give compound 13h–l.

W.S. Park et al. / Journal of Fluorine Chemistry 130 (2009) 1001–1010
1009
4.2.19. Preparation of (R)-4-{1-acetyl-2-[3-amino-4-(2,4,5-
trifluorophenyl)butyryl]-[1,2,5]triazepine-5-carbonyl}benzoic
acidꢀHCl (13p)
was purified by silica gel column chromatography (ethyl acetate/
MeOH: 4/1) to give compound 15d (81 mg, 83%). 1H NMR (CD3OD,
200 MHz):
d 8.72–8.63 (m, 1H), 8.09–7.89 (m, 1H), 7.59–7.43 (m,
To a solution of (R)-4-{1-acetyl-2-[3-tert-butoxycarbonyla-
mino-4-(2,4,5-trifluorophenyl)butyryl]-[1,2,5]triazepane-5-car-
bonyl}benzoic acid methyl ester 12o (50 mg, 0.081 mmol) in THF
(1 mL) and MeOH (1 mL), was added LiOHꢀH2O (7 mg, 0.161 mmol
in 1 mL water). The reaction mixture was stirred for 12 h at room
temperature, and then acidified by 2 N HCl to adjust around pH 4.
The reaction mixture was diluted with brine and ethyl acetate. The
organic layer was separated, dried and evaporated to give (R)-4-{1-
acetyl-2-[3-tert-butoxycarbonylamino-4-(2,4,5-trifluorophenyl)-
butyryl]-[1,2,5]triazepane-5-carbonyl}benzoic acid (46.5 mg,
1H), 4.60–4.01 (m,4H), 3.74–3.01 (m, 5H), 2.35–1.96 (m, 3H); LC-
MS: m/z (relative intensity) 249 (MH+); IR 3390, 2938, 1660, 1658.
4.3.3. Preparation of (R)-tert-butyl-4-(1-acetyl-2-nicotinoyl-1,2,5-
triazepan-5-yl)-4-oxo-1-(2,4,5-trifluorophenyl)butan-2-ylcarbamate
(16d)
To a solution of (R)-3-(tert-butoxycarbonylamino)-4-(2,4,5-
trifluorophenyl)butanoic acid (50 mg, 0.150 mmol) in CH2Cl2
(2 mL), were added 1-(3-dimethylaminopropyl)-3-ethyl carbodii-
mide hydrochloride (EDCI, 58 mg, 0.300 mmol), DMAP (1 mg,
0.008 mmol), TEA (0.006 mL, 45 mmol) and (2-nicotinoyl-1,2,5-
triazepan-1-yl)ethanone 15d (45 mg, 0.18 mmol). The reaction
mixture was stirred for 12 h at room temperature and diluted with
brine and CH2Cl2. The organic layer was separated, dried over
MgSO4 and evaporated. The residue was purified by silica gel
column chromatography (ethyl acetate/MeOH: 4/1) to obtain 16d
95%). 1H NMR (CDCl3, 300 MHz):
d 8.23–8.08 (m, 2H), 7.61–7.33
(m, 2H), 7.23–7.07 (m, 1H), 7.00–6.80 (m, 1H), 5.30 (br, 1H), 4.70–
4.38 (m, 2H), 3.90–3.38 (m, 7H), 3.03–2.64 (s, 3H), 2.80–2.26 (m,
4H), 1.38 (s, 9H); LC-MS: m/z 607 (MH+).
To a solution of (R)-4-{1-acetyl-2-[3-tert-butoxycarbonyla-
mino-4-(2,4,5-trifluorophenyl)butyryl]-[1,2,5]triazepane-5-car-
bonyl}benzoic acid (36 mg, 0.059 mmol) in ethyl acetate (2 mL),
was added 4 M-HCl/1,4-dioxane (2 mL) and the mixture was
stirred for 12 h at room temperature. The solvents were
evaporated, and the residue was crystallized with ether to give
compound 13p (30 mg, 93%, white solid). 186–188 8C; 1H NMR
(66 mg, 78%). 1H NMR (CDCl3, 200 MHz):
d 8.78–8.67 (m, 2H),
7.80–7.76 (m, 1H), 7.42–7.32 (m, 1H), 7.18–7.00 (m, 1H), 6.95–6.88
(m, 1H), 5.32 (s, 1H), 4.66–4.12 (m, 1H), 4.08–3.72 (m, 2H), 3.65–
3.04 (m, 6H), 2.97–2.90 (m, 2H), 2.65–2.57 (m, 2H), 2.27–2.12 (m,
3H), 1.39 (s, 9H); LC-MS: m/z 564 (MH+).
(DMSO-d6, 300 MHz):
d 8.00–7.98 (m, 2H), 7.54–7.51 (m, 4H),
4.20–3.80 (m, 2H), 3.74–3.63 (m, 2H), 3.57 (s, 3H), 3.41–3.30 (m,
5H), 3.17–2.78 (m, 3H), 2.08–1.84 (m, 2H); IR 3441, 2925, 2889,
1664, 1631; HRMS calcd. for C24H25F3N4O5: 506.1777; found,
506.1743.
4.3.4. (R)-1-(1-Acetyl-2-nicotinoyl-1,2,5-triazepan-5-yl)-3-amino-
4-(2,4,5-trifluorophenyl)butan-1-one hydrochlorideꢀHCl (17d)
To a solution of (R)-tert-butyl-4-(1-acetyl-2-nicotinoyl-1,2,5-
triazepan-5-yl)-4-oxo-1-(2,4,5-trifluorophenyl)butan-2-ylcarba-
mate 16d (30 mg, 0.054 mmol) in ethyl acetate (1 mL), was added
4 M-HCl/1,4-dioxane (1 mL) and the mixture was stirred for 12 h at
room temperature. The solvents were evaporated, and the residue
was crystallized with ether to give compound 17d (25 mg, 93%,
4.3. General procedure for the synthesis of compound 17
(Example: 17d)
4.3.1. Preparation of benzyl-1-acetyl-2-nicotinoyl-1,2,5-triazepane-
5-carboxylate (14d)
white solid). 171–173 8C; 1H NMR (MeOH-d4, 300 MHz):
d 9.08–
9.00 (m, 2H), 8.88–8.51 (m, 1H), 8.11–8.04 (m, 1H), 7.30–7.20 (m,
1H), 7.15–7.13 (m, 1H), 4.69–4.39 (m, 1H), 4.30–4.02 (m, 2H),
3.82–3.63 (m, 4H), 3.10–2.99 (m, 3H), 2.81–2.60 (m, 2H), 2.01–1.86
(m, 6H); LC-MS: m/z 463 (MH+); IR 3423, 2927, 2871, 1631.
To a solution of benzyl-1,2,5-triazepane-5-carboxylateꢀHCl 4
(100 mg, 0.324 mmol) in CH2Cl2, were added acetyl chloride
(0.023 mL, 0.324 mmol) and TEA (0.18 mL, 1.298 mmol) at 0 8C.
The reaction mixture was stirred for 12 h at room temperature, and
diluted with brine and CH2Cl2. The organic layer was separated,
dried over MgSO4 and evaporated. The residue was purified by
silica gel column chromatography (ethyl acetate/MeOH: 4/1) to
obtain benzyl-1-acetyl-1,2,5-triazepane-5-carboxylate (45 mg,
4.3.5. Preparation of (R)-3-amino-1-(1,2,5-triazepan-5-yl)-4-(2,4,5-
trifluorophenyl)butan-1-oneꢀHCl (17a)
To a solution of (R)-3-(tert-butoxycarbonylamino)-4-(2,4,5-
trifluorophenyl)butanoic acid (33 mg, 0.1 mmol) in CH2Cl2 (1 mL),
were added 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide
hydrochloride (EDCI, 54 mg, 0.3 mmol), TEA (0.07 mL, 0.5 mmol)
45%). 1H NMR (CDCl3, 300 M Hz):
d 7.36–7.33 (m, 5H), 5.70 (br,
1H), 5.16–5.12 (m, 2H), 4.16–4.08 (m, 5H), 3.08–3.00 (m, 1H),
2.94–2.88 (m, 2H), 2.04 (s, 3H); LC-MS: m/z 278 (MH+).
and di-tert-butyl-1,2,5-triazepane-1,2-dicarboxylate
8 (30 mg,
To a solution of benzyl-1-acetyl-1,2,5-triazepane-5-carboxy-
late (200 mg, 0.721 mmol) in CH2Cl2, were added nicotinoyl
chloride (257 mg, 1.442 mmol) and TEA (0.3 mL, 2.164 mmol) at
0oC. The reaction mixture was stirred for 48 h at room temperature
and diluted with brine and CH2Cl2. The organic layer was
separated, dried over MgSO4 and evaporated. The residue was
purified by silica gel column chromatography (ethyl acetate/
MeOH: 9/1) to obtain compound 14d (160 mg, 58%). 1H NMR
0.1 mmol). The reaction mixture was stirred for 12 h at room
temperature and diluted with brine and CH2Cl2. The organic layer
was separated, dried over MgSO4 and evaporated. The residue was
purified by silica gel column chromatography (ethyl acetate/
hexane: 1/1) to obtain compound 16a (43 mg, 70%). 1H NMR
(CDCl3, 300 MHz): d 7.05–6.97 (m, 1H), 6.94–6.88 (m, 1H), 5.64 (br,
1H), 4.22–4.07 (m, 3H), 3.90–3.80 (m, 1H), 3.76–3.39 (m, 3H),
3.27–3.39 (m, 3H), 3.27–3.05 (m, 2H), 2.93–2.90 (m, 2H), 2.58–2.53
(m, 2H), 1.46 (s, 18H), 1.37 (s, 9H); LC-MS: m/z 162 (MH+); IR 3433,
2844, 1630.
To a solution of (R)-di-tert-butyl-5-(3-(tert-butoxycarbonyla-
mino)-4-(2,4,5-trifluorophenyl)butanoyl)-1,2,5-triazepane-1,2-
dicarboxylate 16a (30 mg, 0.049 mmol) in ethyl acetate (1 mL),
was added 4 M-HCl/1,4-dioxane (1 mL) and the mixture was
stirred for 16 h at room temperature. The solvents were
evaporated, and the residue was crystallized with ether to give
compound 17a (18 mg, 98%, white solid). 117–119 8C; 1H NMR
(CDCl3, 300 M Hz):
d 8.73–8.55 (m, 2H), 7.87–7.84 (m, 1H), 7.53–
7.31 (m, 6H), 5.22 (s, 2H), 4.70–4.20 (m, 2H), 3.84–3.39 (m, 6H),
2.19–1.79 (m, 3H); LC-MS: m/z 383 (MH+); IR 3036, 2947,
1679,1660.
4.3.2. Preparation of 1-(2-nicotinoyl-1,2,5-triazepan-1-yl)ethanone
(15d)
To a solution of benzyl-1-acetyl-2-nicotinoyl-1,2,5-triazepane-
5-carboxylate 14d (150 mg, 0.392 mmol) in methanol (3 mL),
added 10%-Pd/C (83 mg, 20 mol%). The reaction mixture was
stirred for 12 h in hydrogen atmosphere, filtered through celite,
washed with additional methanol and concentrated. The residue
(DMSO-d6, 300 MHz):
d 8.19 (brs, 3H), 7.63–7.50 (m, 2H), 3.73–
3.57 (m, 5H), 3.35–3.11 (m, 4H), 3.07–2.91 (m, 2H), 2.82–2.66 (m,
2H); LC-MS: m/z 317 (MH+); IR 3423, 2930, 1631.

1010
W.S. Park et al. / Journal of Fluorine Chemistry 130 (2009) 1001–1010
4.3.6. (R)-1-(1-Acetyl-1,2,5-triazepan-5-yl)-3-amino-4-(2,4,5-
reader with an excitation wavelength of 485 nm and an emission
wavelength of 530 nm. The effect of test compounds on CYP 3A4
enzyme was calculated as the percentage of the enzyme activity.
trifluorophenyl)butan-1-oneꢀHCl (17b)
1H NMR (MeOH-d4, 300 MHz):
d 7.35–7.28 (m, 1H), 7.18–7.08
(m, 1H), 3.80–3.67 (m, 7H), 3.64–3.48 (m, 2H), 3.10–2.83 (m, 4H),
2.81–2.60 (m, 3H), 2.19–1.93 (m, 3H); LC-MS: m/z 359 (MH+); IR
3415, 2923, 2853, 1692, 1633.
Acknowledgement
This research was supported by the Center for Biological
Modulators of the 21st Century Frontier R&D Program, Ministry of
Education, Science and Technology, Korea.
4.3.7. (R)-1,10-(5-(3-Amino-4-(2,4,5-trifluorophenyl)butanoyl)-
1,2,5-triazepane-1,2-diyl)diethanoneꢀHCl (17c)
1H NMR (MeOH-d4, 300 MHz):
d 7.28–7.18 (m, 1H), 7.16–7.10
References
(m, 1H), 4.35–4.29 (m, 2H), 4.10–3.90 (m, 1H), 3.74–3.71 (m, 2H),
3.56–3.43 (m, 3H), 3.20–2.95 (m, 5H), 2.87–2.50 (m, 2H), 2.17–1.87
(m, 6H); LC-MS: m/z 401 (MH+); IR 3423, 2932, 2888, 1633.
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NADP+, 3.3 mM glucose 6-phosphate, 3.3 mM MgCl2ꢀ6H2O, and
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dibenzylfluorescein, DBF). The plate was further incubated for
20 min, followed by the addition of the stop solution to terminate
the enzyme activity. Background reading was measured in a
similar manner except for the E/S mixture which was added after
the enzyme reaction was terminated. The fluorescence of DBF
metabolite fluorescein was measured on a fluorescence plate