Journal of Medicinal Chemistry
ARTICLE
The molecule also possessed excellent PK across three species,
was potent in primary AML patient blast samples, and showed
strong efficacy in a Ba/F3-FLT3-ITD leukemia mouse model.
On the basis of these findings, compound 37 was selected to
move forward toward preclinical evaluation.
2.02ꢀ1.89 (m, 2H), 1.82 (dt, J = 13.1, 11.1 Hz, 2H), 1.59ꢀ1.47 (m,
4H). Data for trans-7: FIA-MS: 291.1 [M + 1]. 1H NMR (500 MHz,
DMSO-d6): δ 8.14 (d, J = 8.7 Hz, 2H), 7.52 (d, J = 8.7 Hz, 2H),
3.60ꢀ3.54 (m, 4H), 2.63 (tt, J = 11.9, 3.3 Hz, 1H), 2.6 (m, 4H), 2.30
(m, 1H), 1.93 (d, J = 11.5 Hz, 2H), 1.88 (d, J = 11.9 Hz, 2H), 1.51 (q,
J = 13.6 Hz, 2H), 1.36 (q, J = 12.6 Hz, 2H).
4-(trans-4-Morpholinocyclohexyl)aniline (trans-8) and
N3-(4-(trans-4-Morpholinocyclohexyl)phenyl)-1-(pyridin-2-yl)-
1H-1,2,4-triazole-3,5-diamine (37). To a solution of 4-(trans-4-(4-
nitrophenyl)cyclohexyl)morpholine (150 mg, 0.52 mmol) in MeOH
(15 mL) were added zinc dust (169 mg, 2.58 mmol) and ammonium
chloride (110 mg, 2.0 mmol). The resulting suspension was heated under
reflux for 1 h, cooled to room temperature, filtered through Celite, and
washed with MeOH. The filtrate was evaporated to give crude 4-(trans-4-
morpholinocyclohexyl)aniline (trans-8). LC-MS: 261.1 [M + 1]. Without
further purification, the aniline was dissolved in isopropanol (20 mL) and
stirred with diphenyl cyanocarbonimidate (129 mg, 0.54 mmol) for 5 days
under N2. The solvent was removed in vacuo, and the residue was purified
by flash chromatography (SiO2) (CH2Cl2/MeOH/28% NH4OH 96:4:0.4)
to give phenyl N0-cyano-N-(4-(trans-4-morpholinocyclohexyl)phenyl)-
carbamimidate as an off-white solid (113 mg, 57% yield). FIA-MS: 405.1
[M + 1], 403.2 [M ꢀ 1]. 1H NMR (500 MHz, DMSO-d6): δ 10.6 (s, 1H,
NH), 7.44 (t, J = 7.8 Hz, 2H), 7.35 (d, J = 8.3 Hz, 2H), 7.32ꢀ7.21 (m, 5H),
3.57 (m, 4H), 2.47 (m, 1H), 2.7ꢀ2.5 (m, 5H), 2.31ꢀ2.23 (m, 1H), 1.92 (d,
J = 10.0 Hz, 2H), 1.84 (d, J = 11.7 Hz, 2H), 1.45 (q, J = 13.7 Hz, 2H), 1.33
(q, J = 13.7 Hz, 2H).
’ EXPERIMENTAL SECTION
All commercially available reagents and anhydrous solvents were used
without further purification. Purity assessment for final compounds
based on analytical HPLC: column, 4.6 mm ꢁ 50 mm Waters YMC Pro-
C18 column, 5 μm, 120A. Mobile phases are as follows: A, H2O with
0.2% formic acid; B, acetonitrile with 0.2% formic acid; gradient,
10ꢀ90% B in 3 min with 5 min run time. The flow rate is 1.5 mL/min.
Unless specified otherwise, all compounds were g95% purity. Mass
samples were analyzed on a Micro Mass ZQ, ZMD, Quattro LC, or
Quatro II mass spectrometer operated in a single MS mode with
electrospray ionization. Samples were introduced into the mass spectrom-
eter using flow injection (FIA) or chromatography. The mobile phase
for all mass analysis consisted of acetonitrileꢀwater mixtures with either
0.2% formic acid or ammonium formate. The high-resolution mass
spectrum was measured using a 9.4T APEX III FTMS Bruker Daltonics
instrument. 1H NMR spectra were recorded either using a Bruker DRX-
500 (500 MHz) or a Bruker Avance II-300 (300 MHz) instrument. The
column chromatography was performed using Merck silica gel 60
(0.040ꢀ0.063 mm). Preparative reversed phase chromatography was
carried out using a Gilson 215 liquid handler coupled to a UVꢀvis 156
Gilson detector, an Agilent Zorbax SB-C18 column, 21.2 mm ꢁ 100 mm,
a linear gradient from 10ꢀ90% CH3CN in H2O over 10 min (0.1%
trifluoroacetic acid); the flow rate was 20 mL/min. Most of the anilines and
the hydrazines were commercially available or synthesized following
literature procedures.
4-(4-Nitrophenyl)cyclohexanone (6). To a solution of 4-phe-
nylcyclohexanone (4.36 g, 25 mmol) in dry acetonitrile (200 mL) cooled
with an acetoneꢀdry ice bath was added nitronium tetrafluoroborate
(4.68 g, 35 mmol) in one portion under N2. After it was stirred for
15 min, the reaction mixture was stirred at 0 ꢀC for 2 h, treated with ice
chips, and evaporated. The residue was suspended in water and extracted
with ethyl acetate (EtOAc) (3ꢁ), and the organic phase was washed
with brine, dried (Na2SO4), filtered, and evaporated. The residue was
purified by flash chromatography (SiO2) eluted with EtOAc/hexanes
(15:85) to give 4-(2-nitrophenyl)cyclohexanone (475 mg, yellow solid,
8.6% yield) and then the desired product 4-(4-nitrophenyl)cyclohexanone
6 (2.36 g, yellow solid, 43% yield). FIA-MS: 220.1 [M + 1]. 1H NMR (500
MHz, CDCl3): δ 8.12 (dt, J = 8.7, 2.2, 2H), 7.34 (dt, J = 8.7, 2.2, 2H), 3.08
(tt, J = 12.2, 3.4 Hz, 1H), 2.51ꢀ2.43 (m, 4H), 2.18 (ddd, J = 10.5, 5.8,
3.2 Hz, 2H), 1.97ꢀ1.83 (m, 2H).
A mixture of phenyl N0-cyano-N-(4-(trans-4-morpholinocyclohexyl)-
phenyl)carbamimidate (113 mg, 0.28 mmol) and 2-pyridylhydrazine
(32 mg, 0.29 mmol) in isopropanol (3 mL) was heated in a microwave
oven at 180 ꢀC for 10 min. After the mixture was cooled, the precipitate
was collected and washed with isopropanol to give 61 mg of
N3-(4-(trans-4-morpholinocyclohexyl)phenyl)-1-(pyridin-2-yl)-1H-1,2,
4-triazole-3,5-diamine (37). The product was further purified by reverse
phase HPLC (C-18, water/CH3CN). LC-MS: 420.1 [M + 1]. 1H NMR
(500 MHz, DMSO-d6): δ 9.59 (br. s, 1H), 8.99 (s, 1H), 8.41 (d,
J = 4.4 Hz, 1H), 7.97 (t, J = 7.8 Hz, 1H), 7.68 (d, J = 8.3 Hz, 1H), 7.65
(br. s, 1H), 7.54 (d, J = 8.5 Hz, 2H), 7.21 (dd, J = 7.2, 5.5, 1H), 7.11 (d,
J = 8.4 Hz, 2H), 4.02 (d, J = 11.3 Hz, 2H), 3.70 (t, J = 11.9 Hz, 2H), 3.44
(d, J = 11.8 Hz, 2H), 3.28 (m, 1H), 3.20ꢀ3.09 (m, 2H), 2.45 (t, J = 11.6
Hz, 1H), 2.18 (d, J = 11.8 Hz, 2H), 1.96 (d, J = 12.5 Hz, 2H), 1.58 (q, J =
11.7 Hz, 2H), 1.49 (q, J = 12.7 Hz, 2H).
4-(cis-4-Morpholinocyclohexyl)aniline (cis-50) and N3-(4-(cis-
4-Morpholinocyclohexyl)phenyl)-1-(pyridin-2-yl)-1H-1,2,4-
triazole-3,5-diamine (38). As described for trans-8, with 4-(cis-4-(4-
nitrophenyl)cyclohexyl)morpholine (428 mg, 1.47 mmol), zinc dust
(482 mg, 7.37 mmol) and ammonium chloride (316 mg, 5.90 mmol) in
MeOH (15 mL) gave cis-50. After treatment with diphenyl cyanocarbo-
nimidate (369 mg, 1.55 mmol) in isopropanol (20 mL), phenyl N0-
cyano-N-(4-(cis-4-morpholinocyclohexyl)phenyl)carbamimidate was
obtained as a yellow solid (328 mg, 55% yield). LC-MS: 404.2 [M + 1].
1H NMR (500 MHz, DMSO-d6) δ 10.7 (s, 1H), 7.44 (t, J = 7.9 Hz, 2H),
7.37 (d, J = 8.5 Hz, 2H), 7.33ꢀ7.22 (m, 5H), 3.61 (m, 4H), 2.67ꢀ2.61
(m, 1H), 2.39 (br. s, 4H), 2.17 (br. s, 1H), 1.96ꢀ1.90 (m, 2H),
1.86ꢀ1.69 (m, 2H), 1.55ꢀ1.42 (m, 4H).
4-(cis-4-(4-Nitrophenyl)cyclohexyl)morpholine (cis-7) and
4-(trans-4-(4-Nitrophenyl)cyclohexyl)morpholine (trans-7). A
suspension of 4-(4-nitrophenyl)cyclohexanone 6 (493 mg, 2.28 mmol),
morpholine (0.2 mL, 2.28 mmol), and sodium triacetoxyborohydride
(678 mg, 3.2 mmol) in THF (15 mL) was stirred for 24 h. Thin-layer
chromatography (TLC) indicated that the reaction was incomplete.
Additional sodium triacetoxyborohydride (151 mg) was added. The
reaction mixture was stirred for another 24 h, treated with saturated
sodium bicarbonate, and extracted with EtOAc (3ꢁ). The combined
organic phases were washed with brine, dried over anhydrous Na2SO4,
filtered, and evaporated. The crude was purified by flash chromatography
(SiO2) eluted with dichloromethane (CH2Cl2)/methanol (MeOH)/28%
ammonium hydroxide (NH4OH) (98:2:0.2) to give cis-7 as a yellow
oil (428 mg, 65% yield) and trans-7 as a yellow solid (150 mg, 23%).
Data for cis-7: FIA-MA: 291.1 [M + 1]. 1H NMR (500 MHz, DMSO-
d6): δ 8.16 (d, J = 8.9 Hz, 2H), 7.52 (d, J = 8.8 Hz, 2H), 3.62 (t, J = 4.6
Hz, 4H), 2.82 (tt, J = 10.9, 3.7 Hz, 1H), 2.39 (br.s, 4H), 2.18 (s, 1H),
As described for 37, with phenyl N0-cyano-N-(4-(cis-4-morpholino-
cyclohexyl) phenyl)carbamimidate (328 mg, 0.81 mmol), 2-pyridylhy-
drazine (92 mg, 0.85 mmol) in isopropanol (3 mL) to give 134 mg of 38
after reverse phase HPLC purification. LC-MS: 420.1 [M + 1]. 1H NMR
(500 MHz, DMSO-d6): δ 9.21 (br. s, 1H), 9.01 (s, 1H), 8.41 (d, J = 3.2
Hz, 1H), 7.98 (td, J = 7.85, 1.86, 1H), 7.68 (d, J = 8.4 Hz, 1H), 7.65 (s,
1H), 7.59 (d, J= 8.6 Hz, 2H), 7.23 (d, J= 8.6 Hz, 2H), 7.22ꢀ7.17 (m, 1H),
3.97 (d, J = 10.9 Hz, 2H), 3.68 (t, J = 11.8 Hz, 2H), 3.49 (d, J = 12.2 Hz,
2H), 3.32 (br. s, 1H), 3.04(q, J=11.3 Hz, 2H),2.85 (br. s,1H), 2.18ꢀ2.06
(m, 2H), 1.92ꢀ1.85 (m, 2H), 1.79ꢀ1.70 (m, 4H).
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dx.doi.org/10.1021/jm200712h |J. Med. Chem. 2011, 54, 7184–7192