Page 5 of 7
Journal of Medicinal Chemistry
methanol-d4) δ ppm 8.52 (s, 1H), 8.09 (d, J = 1.2 Hz, 1H),
resin precursor to 10 (0.1 g, 0.093 mmol) was added a so-
1
2
3
4
5
6
7
8
lution of acetyl chloride (0.057 mL, 0.80 mmol) in DMF (1
mL) followed by DMAP (9.77 mg, 0.08 mmol) and pyri-
dine (0.078 mL, 0.96 mmol). The mixture was shaken at
room temperature for 5 hours, and the resulting resin was
filtered, washed with DMF (3×3 mL), MeOH (3×3 mL),
DCM (3×3 mL), and then dried in high vacuum. To the
resin (0.1 g, 0.16 mmol) was added DCM (1 mL) and HFIP
(0.5 mL) at room temperature. The mixture was shaken at
room temperature for 1 hour, was filtered, the resin was
washed with MeOH/DCM (2×3 mL). The filtrates were
evaporated in vacuo, and the residue was purified by RP
HPLC, ACN/water (contained 0.1% TFA), ACN from 5% to
75% in 14 min. The fractions were combined to afford 14
(0.063 g, TFA salt, 96% pure (Method A), yield 77.8 %) as
a white solid. LC-MS (ESI): m/z 756.0 [M + H]+ (Calc.
7.22 (d, J = 3.1 Hz, 4H), 7.18 – 7.10 (m, 1H), 5.73 (ddd, J =
25.4, 10.7, 3.1 Hz, 1H), 4.73 (dd, J = 17.3, 8.1 Hz, 1H), 4.64 –
4.38 (m, 1H), 4.30 – 4.16 (m, 1H), 3.12 (s, 2H), 3.09 (s, 2H),
2.94 – 2.82 (m, 3H), 2.48 – 2.36 (m, 2H), 2.33 (d, J = 10.2
Hz, 4H), 2.28 – 2.18 (m, 1H), 2.15 (d, J = 3.3 Hz, 3H), 2.05 –
1.95 (m, 1H), 1.92 – 1.76 (m, 4H), 1.76 – 1.52 (m, 6H), 1.46 –
1.28 (m, 1H), 1.25 – 1.14 (m, 1H), 1.10 (dd, J = 6.9, 3.0 Hz,
3H), 1.04 (t, J = 6.9 Hz, 3H), 0.99 (d, J = 6.8 Hz, 2H), 0.93
(td, J = 7.3, 2.1 Hz, 5H), 0.81 (t, J = 6.1 Hz, 3H).
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Methyl
(2S,4R)-4-(2-((1R,3R)-1-acetoxy-3-((2S,3S)-N,3-
dimethyl-2-((R)-piperidine-2-carboxamido)pentanamido)-
4-methylpentyl)thiazole-4-carboxamido)-2-methyl-5-
phenylpentanoate 27. The synthesis was analogous to 1
except
of
(R)-1-(tert-butoxycarbonyl)piperidine-2-
carboxylic acid was used for the final step coupling. To
the final resin was added DCM (1 mL) and HFIP (0.5 mL)
at room temperature. The mixture was shaken at room
temperature for 1h, and the resin was filtered, washed
with MeOH/DCM (3×2 mL). The filtrates were evaporated
in vacuo, and the residue was purified by RP HPLC
ACN/water (0.1% TFA), ACN from 5% to 80% in 14 min,
the pure fractions were lyophilized to give N-Boc-27
(0.060 g, 46.1 %) as a white solid. LC-MS: 814 (M+1)+. To
the solution of N-Boc-27 (59.7 mg, 0.07 mmol) in MeOH
(1 mL) and toluene (2 mL) was added (diazome-
thyl)trimethylsilane (2.0 M in ether) (0.073 mL, 0.15
mmol) at room temperature. The mixture was stirred at
room temperature for 30 min, and was evaporated in vac-
uo. The residue was dissolved in DCM (2 mL) and cooled
to 0 °C and TFA (2 mL) was added. The mixture was
stirred at 0 °C for 1 hour, and was evaporated in vacuo.
The residue was purified by RP HPLC , ACN/water (0.1%
TFA), ACN from 5% to 60% in 14 min. The fractions were
lyophilized to give 27 (48.0 mg, TFA salt, 99% pure
(Method A), 78 % yield) as a solid. LC-MS (ESI): m/z
1
M=755.39). H NMR (400 MHz, methanol-d4) δ ppm 8.04
- 8.13 (m, 2H), 7.46 - 7.60 (m, 1H), 7.21 - 7.30 (m, 4H), 7.11 -
7.22 (m, 1H), 5.65 - 5.81 (m, 1H), 5.50 (s, 2H), 5.20 (d, J =
4.80 Hz, 1H), 4.73 - 4.84 (m, 2H), 4.32 - 4.55 (m, 3H), 4.12
(q, J = 7.07 Hz, 2H), 3.81 (d, J = 13.39 Hz, 1H), 3.21 (br. s.,
1H), 3.08 - 3.16 (m, 2H), 2.84 - 2.99 (m, 2H), 2.49 - 2.70 (m,
1H), 2.21 - 2.48 (m, 2H), 2.12 - 2.20 (m, 2H), 1.96 - 2.09 (m,
3H), 1.77 - 1.96 (m, 2H), 1.34 - 1.76 (m, 7H), 1.26 (t, J = 7.07
Hz, 3H), 1.07 - 1.22 (m, 4H), 0.88 - 1.02 (m, 6H), 0.78 - 0.87
(m, 3H).
Synthesis of (1R,3R)-1-(4-(((2R,4S)-5-amino-4-methyl-5-
oxo-1-phenylpentan-2-yl)carbamoyl)thiazol-2-yl)-3-
((2S,3S)-N,3-dimethyl-2-((R)-1-methylpiperidine-2-
carboxamido)pentanamido)-4-methylpentyl acetate 25.
The synthesis was analogous to 1 except the synthesis was
done on Rink amide resin (0.5 meq/g). To the resin (0.3 g,
0.15 mmol) was added DCM (2 mL) and TFA (2 mL) at
room temperature. The mixture was shaken at room tem-
perature for 1h, and the resin was filtered, washed with
MeOH/DCM (3×2 mL). The filtrates were evaporated in
vacuo, and the residue was purified by RP HPLC
ACN/water (0.1% FA), ACN from 5% to 60% in 14 min, the
pure fractions were lyophilized to give 25 as a solid (0.065
g, FA salt, 97% pure (Method B), yield 55.7 %). LC-MS
1
728.5 [M + H]+ (Calc. M=741.41); H NMR (400 MHz,
methanol-d4) δ ppm 8.03 - 8.82 (m, 2H), 7.17 – 7.29 (m,
5H), 5.69 - 5.74 (m, 1H), 4.78 - 4.70 (m, 1H), 4.36 - 4.43 (m,
2H), 3.83 - 3.85 (m, 1H), 3.59 - 3.61 (m, 3H), 3.37 - 3.42 (m,
1H), 3.11 – 3.13 (m, 3H), 2.99 – 3.06 (m, 1H), 2.85 – 2.95 (m,
2H), 2.58 - 2.67 (m, 1H), 2.36 - 2.46 (m, 1H), 2.24 - 2.33 (m,
2H), 2.16 - 2.17 (m, 3H), 1.86 - 2.04 (m, 5H), 1.58 – 1.78 (m,
5H), 1.14 - 1.18 (m, 4H), 1.06 (d, J = 6.57 Hz, 3H), 1.02 (dd, J
= 6.8, 2.8 Hz, 3H), 0.96 (td, J = 7.4, 5.0 Hz, 3H), 0.86 (d, J
= 6.6 Hz, 1H).
(ESI): m/z 727.5 [M + H]+ (Calc. M=726.41); H NMR (400
1
MHz, methanol-d4) δ ppm 8.09 (s, 1H), 7.23 (s, 2H), 7.22
(s, 3H), 7.19 – 7.13 (m, 1H), 5.72 (ddd, J = 13.6, 11.1, 2.8 Hz,
1H), 4.73 (dd, J = 7.8, 4.4 Hz, 1H), 4.51 – 4.27 (m, 2H), 3.12
(d, J = 3.0 Hz, 3H), 2.90 (dd, J = 6.9, 1.7 Hz, 2H), 2.80 –
2.65 (m, 1H), 2.59 – 2.45 (m, 4H), 2.44 – 2.19 (m, 2H), 2.15
(d, J = 3.8 Hz, 3H), 2.07 – 1.94 (m, 2H), 1.92 – 1.79 (m, 4H),
1.78 – 1.42 (m, 6H), 1.26 – 1.15 (m, 1H), 1.13 (dd, J = 7.0, 1.5
Hz, 3H), 1.02 (ddd, J = 14.2, 6.7, 2.0 Hz, 7H), 0.94 (td, J =
7.4, 2.1 Hz, 3H), 0.84 (d, J = 6.6 Hz, 3H).
(1R,3R)-1-(4-(((S)-1-amino-3-phenylpropan-2-
yl)carbamoyl)thiazol-2-yl)-3-((2S,3S)-N,3-dimethyl-2-((R)-
1-methylpiperidine-2-carboxamido)pentanamido)-4-
methylpentyl acetate 28. (1R,3R)-1-(4-(((S)-1-amino-3-
phenylpropan-2-yl)carbamoyl)thiazol-2-yl)-3-((2S,3S)-
N,3-dimethyl-2-((R)-1-methylpiperidine-2-
carboxamido)pentanamido)-4-methylpentyl acetate 30. 2-
((1R,3R)-1-acetoxy-3-((2S,3S)-N,3-dimethyl-2-((R)-1-
methylpiperidine-2-carboxamido)pentanamido)-4-
methylpentyl)thiazole-4-carboxylic acid9b (0.050 g, 0.08
(1R,3R)-3-((2S,3S)-N,3-dimethyl-2-((R)-1-
methylpiperidine-2-carboxamido)pentanamido)-1-(4-
(((2R,4S)-5-hydrazinyl-4-methyl-5-oxo-1-phenylpentan-2-
yl)carbamoyl)thiazol-2-yl)-4-methylpentyl acetate 26. Syn-
thesis was analogous to 1 except the synthesis was done
on 2-CTC that was treated with hydrazine to afford the
corresponding hydrazine-resin; white solid (0.061 g, FA
salt, 99% pure (Method B), yield 48.4 %). LC-MS (ESI):
m/z 742.59 [M + H]+ (Calc. M=741.42); 1H NMR (400 MHz,
mmol) was added to
a
solution of 2,3,4,5,6-
pentafluorophenol (25.4 mg, 0.138 mmol) and (0.022 mL,
0.138 mmol) in DCM (5 mL) at 0 °C. The solution was
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