DOI: 10.3109/14756366.2015.1010530
Reversible MAGL inhibitors
5
nitrogen for 10 min. After that period, commercially available
bromo-substituted aldehydes 10–12 (1 eq), 2 M aqueous Na2CO3 1.7 Hz), 7.46–7.52 (m, 2H), 7.63–7.66 (m, 2H), 7.76 (AA0XX0,
1H-NMR (CDCl3, 400 MHz) d (ppm): 7.42 (td, 1H, J ¼ 7.3,
(6 ml/2.7 mmol bromo-derivative) and the appropriate substituted 2H, JAX ¼ 8.4 Hz, JAA /XX ¼ 2.1 Hz), 7.96 (AA0XX0, 2H,
0
0
0
0
phenylboronic acid (1.6 eq) were sequentially added. The result- JAX ¼ 8.4 Hz, JAA /XX ¼ 1.7 Hz), 10.06 (s, 1H).
ing mixture was heated at 100 ꢀC in a sealed vial under nitrogen
for 24 h. After being cooled to RT, the mixture was diluted with 40-Fluoro-[1,10-biphenyl]-4-carbaldehyde (15b)
water and extracted with EtOAc. The combined organic phase
White solid, yield: 98% (527.2 mg) from aldehyde 12 and
4-fluorophenylboronic acid. Rf ¼ 0.17 (n-hexane/EtOAc 95:5).
were dried and concentrated. The crude product was purified
by flash chromatography using the indicated eluent and pure
fractions containing the desired biphenyl compound were
evaporated to dryness affording the desired product.
1H-NMR (CDCl3, 400 MHz) d (ppm): 7.17 (double AA0XX0,
2H, 3JHF-o ¼ 9.7 Hz, JAX ¼ 8.7 Hz, JAA /XX ¼ 2.6 Hz), 7.61 (double
0
0
4
AA0XX0, 2H, JHF-m ¼ 5.3 Hz, JAX ¼ 8.9 Hz, JAA /XX ¼ 2.6 Hz),
0
0
7.70 (AA0XX0, 2H, JAX ¼ 8.2 Hz, JAA /XX ¼ 1.7 Hz), 7.95
0
0
[1,10-Biphenyl]-2-carbaldehyde (13a)
(AA0XX0, 2H, JAX ¼ 8.5 Hz, JAA /XX ¼ 1.8 Hz), 10.06 (s, 1H).
40-Methoxy-[1,10-biphenyl]-4-carbaldehyde (15c)
0
0
Yellow oil, yield: 76% (490.3 mg) from aldehyde 10 and
phenylboronic acid. Rf ¼ 0.16 (n-hexane/EtOAc 98:2).
1H-NMR (CDCl3, 400 MHz) d (ppm): 7.38–7.40 (m, 2H),
7.44–7.53 (m, 5H), 7.65 (td, 1H, J ¼ 7.5, 1.5 Hz), 8.04 (ddd, 1H,
J ¼ 7.8, 1.4, 0.4 Hz), 9.99 (s, 1H).
White solid, yield: 95% (542.0 mg) from aldehyde 12 and
4-methoxyphenylboronic acid. Rf ¼ 0.18 (n-hexane/EtOAc 95:5).
1H-NMR (CDCl3, 400 MHz) d (ppm): 3.87 (s, 3H),0 7.01
0
(AA0XX0, 2H, JAX ¼ 8.9 Hz, JAA /XX ¼ 2.6 Hz), 7.60 (AA XX , 2H,
0
0
40-Fluoro-[1,10-biphenyl]-2-carbaldehyde (13b)
0
0
0
0
JAX ¼ 8.9 Hz, JAA /XX ¼ 2.6 Hz), 7.72 (AA XX , 2H, JAX ¼ 8.2 Hz,
0
0
0
0
0
0
White solid, yield: 99% (619.3 mg) from aldehyde 10 and JAA /XX ¼ 1.7 Hz), 7.93 (AA XX , 2H, JAX ¼ 8.5 Hz, JAA /XX
¼
4-fluorophenylboronic acid. Rf ¼ 0.20 (n-hexane/EtOAc 95:5).
1.8 Hz), 10.04 (s, 1H).
1H-NMR (CDCl3, 400 MHz) d (ppm): 7.17 (double AA0XX0,
2H, 3JHF-o ¼ 9.5 Hz, JAX ¼ 8.6 Hz, JAA /XX ¼ 2.5 Hz), 7.36 (double Procedure for synthesis of compound (Z)-3-([1,10-biphe-
0
0
4
AA0XX0, 2H, JHF-m ¼ 5.3 Hz, JAX ¼ 8.6 Hz, JAA /XX ¼ 2.5 Hz), nyl]-4-yl)-2-acetamidoacrylic acid (19)
0
0
7.42 (dd, 1H, J ¼ 7.7, 0.7 Hz), 7.48–7.53 (m, 1H), 7.64 (td, 1H,
A suspension of azlactone 18a (150 mg, 0.570 mmol) in 1.5 ml of
1 N sodium hydroxide solution was heated at 90 ꢀC until
homogeneous. The clear solution was cooled in an ice bath and
then was acidified to pH 1–2 with a hydrochloric acid solution 3 N
J ¼ 7.5, 1.4 Hz), 8.02 (dd, 1H, J ¼ 7.8, 1.3 Hz), 9.97 (s, 1H).
40-Methoxy-[1,10-biphenyl]-2-carbaldehyde (13c)
Light yellow oil, yield: 99% (667.7 mg) from aldehyde 10 and and a white precipitate was formed. The precipitate thus formed
4-methoxyphenylboronic acid. Rf ¼ 0.14 (n-hexane/EtOAc 95:5). was isolated by filtration and washed with distilled water. The
1H-NMR (CDCl3, 400 MHz) d (ppm): 3.88 (s, 3H),0 7.01 precipitate was then dissolved in acetone, dried, filtered and
0
(AA0XX0, 2H, JAX ¼ 8.8 Hz, JAA /XX ¼ 2.5 Hz), 7.31 (AA XX , 2H, evaporated under reduced pressure to obtain a white solid.
0
0
0
0
JAX ¼ 8.7 Hz, JAA /XX ¼ 2.5 Hz), 7.42–7.49 (m, 2H), 7.62 (td, 1H, The solid was further purified by crystallization in n-hexane/
J ¼ 7.5, 1.4 Hz), 8.00 (dd, 1H, J ¼ 7.8, 1.4 Hz), 10.00 (s, 1H).
[1,10-Biphenyl]-3-carbaldehyde (14a)
EtOAc to afford the pure desired compound 19 in 14% yield
(21.8 mg) as white crystals.
1H-NMR (DMSO-d6, 400 MHz) d (ppm): 2.01 (s, 3H), 7.26
(s, 1H), 7.36–7.41 (m, 1H), 7.46–7.50 (m, 2H), 7.69–7.74
(m, 6H), 9.53 (bs, 1H), 12.66 (bs, 1H).
Light yellow oil, yield: 88% (868.0 mg) from aldehyde 11 and
phenylboronic acid. Rf ¼ 0.28 (n-hexane/EtOAc 95:5).
1H-NMR (CDCl3, 400 MHz) d (ppm): 7.40 (tt, 1H, J ¼ 7.3,
1.6 Hz), 7.46–7.51 (m, 2H), 7.59–7.65 (m, 3H), 7.85–7.89 (m,
2H), 8.11 (t, 1H, J ¼ 1.5 Hz), 10.10 (s, 1H).
13C-NMR (DMSO-d6, 100 MHz) d (ppm): 22.56, 126.61 (2C),
126.66 (2C), 127.36, 127.82, 129.01 (3C), 130.35, 130.50,
132.88, 139.26, 140.53, 166.37, 169.13.
40-Fluoro-[1,10-biphenyl]-3-carbaldehyde (14b)
Biological evaluation
MAGL inhibition assay
Colorless oil, yield: 99% (668.9 mg) from aldehyde 11 and
4-fluorophenylboronic acid. Rf ¼ 0.14 (n-hexane/EtOAc 95:5).
Human recombinant MAGL, and 4-nitrophenylacetate substrate
(4-NPA) were from Cayman Chemical. The IC50 values for
compounds were generated in 96-well microtiter plates. The
MAGL reaction was conducted at room temperature at a final
volume of 200 ml in 10 mM Tris buffer, pH 7.2, containing 1 mM
1H-NMR (CDCl3, 400 MHz) d (ppm): 7.17 (double AA0XX0,
3
0
0
2H, JHF-o ¼ 9.8 Hz, JAX ¼ 8.7 Hz, JAA /XX ¼ 2.6 Hz), 7.56–7.63
(m, 3H), 7.81 (ddd, 1H, J ¼ 7.8, 1.9, 1.2 Hz), 7.86 (dt, 1H, J ¼ 7.6,
1.4 Hz), 8.05 (t, 1H, J ¼ 1.6 Hz), 10.09 (s, 1H).
EDTA.
A
total of 150 ml of 4-NPA 133.3 mM (final
40-Methoxy-[1,10-biphenyl]-3-carbaldehyde (14c)
concentration ¼ 100 mM) was added to 10 ml of DMSO containing
the appropriate amount of compound. The reaction was initiated
by the addition of 40 ml of MAGL (11 ng/well) in such a way that
the assay was linear over 30 min. The final concentration of the
analyzed compounds ranged for CAY10499 and JZL-184 from
10 to 0.00001 mM and for the synthesized compounds from 200 to
0.0128 mM. After the reaction had proceeded for 30 min, absorb-
ance values were then measured by using a VictorX3 PerkinElmer
instrument at 405 nm. Two reactions were also run: one reaction
containing no compounds and the second one containing neither
inhibitor nor enzyme. IC50 values were derived from experimental
data using the Sigmoidal dose–response fitting of GraphPad
White crystalline solid, yield: 99% (791.0 mg) from aldehyde 11
and 4-methoxyphenylboronic acid. Rf ¼ 0.12 (n-hexane/EtOAc
95:5).
1H-NMR (CDCl3, 400 MHz) d (ppm): 3.87 (s, 3H), 7.01
(AA0XX0, 2H, JAX ¼ 8.9 Hz, JAA /XX ¼ 2.6 Hz), 7.55–7.60 (m, 3H),
7.80–7.84 (m, 2H), 8.06 (t, 1H, J ¼ 1.6 Hz), 10.08 (s, 1H).
0
0
[1,10-Biphenyl]-4-carbaldehyde (15a)
Light yellow solid, yield: 92% (909.8 mg) from aldehyde 12 and
phenylboronic acid. Rf ¼ 0.23 (n-hexane/EtOAc 95:5).