Journal of Medicinal Chemistry
Article
and concentrated in vacuo. The crude product was dissolved in DCM
(75 mL) and loaded onto a VLC column (height, 8.0 cm; diameter,
9.5 cm; column material, 60H silica gel; column pretreated with
heptane). Gradient elution was carried out with heptane followed by
heptane−EtOAc 4:1 to 2:1. The appropriate fractions were
concentrated in vacuo to yield an intermediate tert-butyl ester (34.1
g, 62%).
was dissolved in EtOAc (500 mL) and then washed with 1 M HCl (3
× 200 mL), water (200 mL), 0.1 M NaOH (200 mL), saturated
NaHCO3 (200 mL), water (200 mL), and brine (200 mL).
Subsequently, the solution was dried over Na2SO4 and concentrated
in vacuo. The crude product was dissolved in DCM (50 mL) and
loaded onto a VLC column (height, 8.0 cm; diameter, 9.5 cm; column
material, 60H silica gel; column pretreated with heptane). Gradient
elution was carried out with heptane followed by heptane−EtOAc 7:1
to 2:1. The appropriate fractions were concentrated in vacuo to yield
an intermediate tert-butyl ester (20.4 g, 54%).
An aliquot of this intermediate tert-butyl ester (17.0 g) was treated
with TFA−DCM 1:3 (230 mL) for 2 h. The mixture was concentrated
in vacuo with DCM−toluene three times. The residue was redissolved
in DCM (200 mL), and then DIPEA (16.4 g, 5.0 equiv) and
pyrazol(Boc)2 (9.4 g, 1.2 equiv) in DCM (200 mL) were added
successively. The mixture was stirred at room temperature for 16 h and
was then concentrated in vacuo, redissolved in DCM (50 mL), and
loaded onto a VLC column (height, 8.0 cm; diameter, 9.5 cm; column
material, 60H silica gel; column pretreated with heptane). Gradient
elution was carried out with heptane followed by 0.1% HOAc in
heptane−EtOAc 2:1 to 1:1. The appropriate fractions were
An aliquot of this intermediate tert-butyl ester (10.4 g) was treated
with TFA−DCM 1:2 (100 mL) for 2 h. The mixture was concentrated
in vacuo with DCM−toluene three times. The residue was redissolved
in DCM (100 mL), and then DIPEA (9.8 g, 5.0 equiv) and
pyrazol(Boc)2 (5.7 g, 1.2 equiv) in DCM (200 mL) were added
successively. The mixture was stirred at room temperature for 16 h and
was then concentrated in vacuo and redissolved in EtOAc (200 mL).
The solution was washed with 1 M HCl (2 × 100 mL), 10% citric acid
(2 × 100 mL), water (2 × 100 mL), and brine (100 mL). The mixture
was dried over Na2SO4, concentrated in vacuo, redissolved in DCM
(40 mL), and loaded onto a VLC column (height, 8.0 cm; diameter,
8.0 cm; column material, 60H silica gel; column pretreated with
heptane). Gradient elution was carried out with heptane followed by
heptane−EtOAc 4:1, 0.1% HOAc in heptane−EtOAc 4:1 to 1:1. The
appropriate fractions were concentrated in vacuo to yield compound
15 (9.9 g, 84%; tR = 14.56 min). HRMS: calcd for C42H53N5O9 [M +
H]+ 772.3901, found 772.3905; ΔM = 0.5 ppm. 1H NMR (600 MHz,
CD3OD): δ = 1.45−1.48 (m, 18 H), 1.25−1.65 (m, 4 H), 1.66 (d, J =
6.9 Hz, 3H), 1.70−1.88 (m, 2 H), 3.32−3.41 (m, 2 H), 3.85* (d, J =
18.9 Hz, 1 H), 3.96 (d, J = 17.3 Hz, 1 H), 4.10−4.38 (m, 5H), 5.48 (q,
J = 6.7 Hz, 1 H), 5.85* (q, J = 6.9 Hz, 1 H), 7.21−7.40 (m, 9H), 7.68
(m, 2 H), 7.78 (m, 2 H). 13C NMR (150 MHz, CD3OD): δ = 16.3*,
17.9, 24.0, 28.2, 28.6, 29.7*, 29.8, 41.7, 45.4, 45.9*, 48.4*, 48.5, 52.5,
53.0*, 53.8*, 56.2, 67.9*, 68.0, 80.6, 84.5, 120.9, 126.2, 126.3, 126.3,
128.2, 128.2, 128.2, 128.8, 128.8*, 129.0*, 129.5, 129.8, 140.8*, 141.1,
142.6, 142.6*, 145.1, 145.2*, 145.3, 154.1*, 154.2, 157.4*, 157.5,
158.3*, 158.4, 164.3, 172.2, 172.6*, 174.5, 175.3*.
Synthesis of Compound 16. An intermediate tert-butyl ester was
prepared as described for compound 15. The intermediate tert-butyl
ester (10.0 g) was treated with TFA−DCM 1:2 (100 mL) for 1 h. The
mixture was concentrated in vacuo with DCM−toluene three times.
The residue was redissolved in DCM (100 mL), and then DIPEA (9.4
g, 5.0 equiv) and Boc2O (4.14 g, 1.3 equiv) in DCM (100 mL) were
added successively. The mixture was stirred at room temperature for
16 h. The mixture was concentrated in vacuo, redissolved in DCM (40
mL), and loaded onto a VLC column (height, 8.0 cm; diameter, 8.0
cm; column material, 60H silica gel; column pretreated with heptane).
Gradient elution was carried out with heptane followed by heptane−
EtOAc 4:1, 0.1% HOAc in heptane−EtOAc 4:1 to 1:1. The
appropriate fractions were concentrated in vacuo to yield compound
16 (2.46 g, 27%; tR = 15.93 min). HRMS: calcd for C36H43N3O7 [M +
H]+ 630.3170, found 630.3171; ΔM = 0.2 ppm. 1H NMR (600 MHz,
CD3OD): δ = 1.41 (s, 9 H), 1.24−1.54 (m, 4 H), 1.66 (d, J = 6.9 Hz,
3H), 1.78−1.89 (m, 2 H), 2.95−3.11 (m, 2 H), 3.86* (d, J = 18.8 Hz,
1 H), 3.96 (d, J = 17.3 Hz, 1 H), 4.11−4.38 (m, 5H), 5.49 (q, J = 6.8
Hz, 1 H), 5.84* (q, J = 6.9 Hz, 1 H), 7.20−7.39 (m, 9H), 7.65 (m, 2
H), 7.78 (d, J = 7.6 Hz, 2 H). 13C NMR (150 MHz, CD3OD): δ =
16.3*, 17.9, 23.9, 24.0*, 28.8, 30.5*, 30.7, 41.0, 41.1*, 45.3, 45.9*,
48.4*, 48.4, 52.6*, 53.0*, 53.8, 56.1, 67.9*, 68.0, 79.8, 120.9, 126.2,
126.3, 126.3*, 128.2*, 128.2*, 128.2, 128.8, 129.0, 129.6*, 129.7,
141.1, 142.6*, 142.6, 145.1, 145.2*, 145.3, 158.3*, 158.5, 158.5, 172.3,
172.6*, 174.5, 175.4*.
concentrated in vacuo to yield compound 13 (13.0 g, 68%; tR
=
14.30 min). HRMS: calcd for C41H51N5O9 [M + H]+ 758.3764, found
758.3764; ΔM = 0.0 ppm. 1H NMR (600 MHz, CD3OD): δ = 1.46 (s,
9 H), 1.47 (s, 9 H), 1.28−1.85 (m, 6 H), 3.28 (t, J = 7 Hz, 2 H), 3.34*
(m, 2 H), 3.80 (d, J = 17.2 Hz, 1 H), 3.90* (d, J = 18.7 Hz, 1 H),
4.14−4.50 (m, 5 H), 4.68 (m, 1 H), 4.85 (m, 1 H), 7.08−7.40 (m, 9
H), 7.64 (m, 2 H), 7.77 (m, 2 H). 13C NMR (150 MHz, CD3OD): δ =
23.9, 24.0*, 28.2, 26.6, 29.6, 26.7*, 32.5*, 32.8, 41.6, 41.7*, 48.4,
48.5*, 51.2*, 51.2*, 52.4, 53.3, 68.0, 80.5, 80.6*, 84.7, 120.9, 126.2*,
126.3, 128.2, 128.2, 128.5, 128.8, 128.9, 129.0, 129.2, 129.7, 129.9,
137.7, 137.8*, 142.6*, 142.6, 145.1, 145.3*, 145.3, 154.1*, 154.1,
157.4, 158.3, 158.4*, 164.2*, 164.3, 172.0, 172.4*, 175.2*, 175.3.
Synthesis of Compound 14. An intermediate tert-butyl ester was
prepared as described for compound 13. The intermediate tert-butyl
ester (17.0 g) was treated with TFA−DCM 1:3 (230 mL) for 2 h. The
mixture was concentrated in vacuo with DCM−toluene three times.
The residue was redissolved in DCM (200 mL), and then DIPEA
(16.4 g, 5.0 equiv) and Boc2O (7.2 g, 1.3 equiv) in DCM (200 mL)
were added successively. The mixture was stirred at room temperature
for 16 h. The mixture was concentrated in vacuo, redissolved in DCM
(50 mL), and loaded onto a VLC column (height, 8.0 cm; diameter,
9.5 cm; column material, 60H silica gel; column pretreated with
heptane). Gradient elution was carried out with heptane followed by
0.1% HOAc in heptane−EtOAc 2:1 to 1:1. The appropriate fractions
were concentrated in vacuo to yield compound 13 (10.7 g, 68%; tR =
15.52 min). HRMS: calcd for C35H41N3O7 [M + H]+ 616.3017, found
616.3022; ΔM = 0.8 ppm. 1H NMR (600 MHz, CD3OD): δ = 1.40 (s,
9 H), 1.41* (s, 9 H), 1.26−1.82 (m, 6 H), 2.93−3.05 (m, 2 H), 3.74
(d, J = 17.2 Hz, 1 H), 3.91* (d, J = 18.7 Hz, 1 H), 4.14−4.52 (m, 5 H),
4.60−4.70 (m, 1 H), 4.85 (m, 1 H), 7.08−7.39 (m, 9 H), 7.65 (m, 2
H), 7.77 (m, 2 H). 13C NMR (150 MHz, CD3OD): δ = 23.9, 24.0*,
28.8, 30.6, 32.6*, 32.8, 41.0, 41.1*, 48.4*, 48.4, 51.2, 52.3*, 52.5*,
53.2, 68.0, 79.8, 120.9, 126.2*, 126.3, 126.3, 128.2, 128.2, 128.5,
128.6*, 128.8, 128.9, 129.0, 129.2, 129.7, 129.9, 137.6, 137.8*, 138.9,
142.6*, 142.6, 145.1, 145.3*, 145.3*, 158.4, 158.5*, 158.5, 172.0,
172.3*, 175.3*, 175.3.
Synthesis of Compound 15. (S)-1-Phenylethylamine (11.5 g)
was dissolved in THF (40 mL), and then Et3N (19.2 g, 2.0 equiv) and
tert-butyl bromoacetate (18.5 g, 1.0 equiv) in THF (40 mL) were
added successively. The mixture was stirred at room temperature for
16 h followed by filtration. The filtrate was concentrated in vacuo, and
then the residue was dissolved in DCM (50 mL) and loaded onto a
VLC column (height, 8.0 cm; diameter, 9.5 cm; column material, 60H
silica gel; column pretreated with heptane). Gradient elution was
carried out with DCM followed by DCM−MeOH 100:1 to 50:1. The
appropriate fractions were concentrated in vacuo to yield an
intermediate amine (12.9 g, 58%).
Fmoc-Lys(Boc)-OH (28.3 g, 1.1 equiv) was dissolved in DCM (650
mL), and then DIPEA (17.7 g, 2.5 equiv) and TBTU (26.4 g, 1.5
equiv) were added under stirring. After 15 min the intermediate amine
in DCM (50 mL) was added. The mixture was stirred at room
temperature for 16 h and concentrated in vacuo. The crude product
General Protocol for Synthesis of Peptidomimetics. Pepti-
domimetics were prepared as previously described.15 In brief, Rink
amide resin (loading, 0.70 mmol/g) and Teflon reactors (10 mL) were
used for all compounds. Fmoc deprotection conditions were the
following: 20% piperidine in DMF (2 × 10 min, each time with 5 mL
under shaking at room temperature). Washing conditions were with
DMF, MeOH, and DCM (each 3 × 3 min with 5 mL). Coupling
conditions were the following: building block, PyBOP, and DIPEA; 2.0
G
dx.doi.org/10.1021/jm401335p | J. Med. Chem. XXXX, XXX, XXX−XXX