B. van der Wildt et al.
Bioorganic & Medicinal Chemistry 42 (2021) 116245
mL, 5.5 mmol). The resulting solution was stirred for 2 h at rt. After
concentration in vacuo, the residue was taken up in DCM (10 mL) and a
solution of compound 2 (1.5 g, 5.0 mmol) and TEA (1.5 mL, 11 mmol) in
DCM (10 mL) was added. The resulting mixture was stirred overnight
and diluted with DCM (50 mL) and 1 M HCl (50 mL). The solids were
collected by filtration, rinsed with water and DCM to obtain the product
as a white solid (2.1 g, 88%). 1H NMR (400 MHz, DMSO‑d6): δ = 10.51
(s, 1H), 10.24 (s, 1H), 9.13 (s, 1H), 8.92 (s, 1H), 8.57 (s, 1H), 8.32 (s,
1H), 8.28 (d, 1H, J = 7.9 Hz), 7.95 (d, 1H, J = 7.8 Hz), 7.90 (s, 1H), 7.78
(t, 1H, J = 7.8 Hz), 7.63 (d, 1H, J = 8.3 Hz), 7.28 (d, 1H, J = 8.4 Hz),
2.25 (s, 3H). 13C NMR (101 MHz, DMSO‑d6): δ = 163.9, 162.5, 152.8,
147.3, 137.8, 136.9, 135.7, 135.7, 131.8, 131.7, 130.4, 129.7, 129.3,
129.2 (q, J = 32.1 Hz), 128.1 (q, J = 3.6 Hz), 124.2 (q, J = 3.9 Hz), 124.0
(q, J = 272.4 Hz), 120.1, 118.7, 118.6, 17.4; ESI-HRMS: m/z calculated
for C21H15BrF3N3NaO2: 500.0193; found 500.0193 [M + Na]+.
137.2, 136.9, 135.8, 135.7, 131.9, 130.4, 129.9, 129.7, 129.4, 129.2 (q,
J = 32.1 Hz), 128.2, 128.1, 124.2 (q, J = 3.8 Hz), 124.0 (q, J = 272.4
Hz), 122.4, 118.7, 118.6, 117.0, 25.1, 17.4; ESI-HRMS: m/z calculated
for C25H20F3N5NaO2: 502.1467; found 502.1461 [M + Na]+.
5.1.7. (1-(2-fluoroethyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-
1H-pyrazole)
A suspension of 4-pyrazoleboronic acid pinacol ester (0.97 g, 5.0
mmol) and NaH (0.18 g, 7.5 mmol) in DMF (20 mL) was stirred for 30
min prior to the addition of 1-fluoro-2-iodoethane (0.45 mL, 5.5 mmol)
and the resulting mixture was stirred overnight at rt. The mixture was
diluted with Et2O (100 mL) and washed with sat. NaHCO3 (3 × 50 mL),
1 M HCl (3 × 50 mL) and brine (1 × 50 mL). The organic fraction was
dried on Na2SO4, filtrated and concentrated in vacuo. Flash column
chromatography (hexanes/EA 1:1) afforded the product as a colorless oil
(0.35 g, 14%). 1H NMR (400 MHz, CDCl3): δ = 7.89 (s, 1H), 7.78 (m,
1H), 4.30 (t, 1H, J = 5.3 Hz), 3.85 (t, 1H, J = 5.4 Hz), 3.63 (t, 1H, J = 6.7
Hz), 3.16 (t, 1H, J = 6.7 Hz), 1.32 (d, 12H, J = 5.3 Hz); 13C NMR (101
MHz, CDCl3): δ = 145.8, 140.7, 137.5, 83.5 (d, J = 10.3 Hz), 70.7 (d, J =
260.1 Hz), 50.3, 24.9; ESI-HRMS: m/z calculated for C11H18BFN2NaO2:
263.1343; found: 263.1341 [M + Na]+.
5.1.4. (4-bromo-N-(2-methyl-5-(3-(trifluoromethyl)benzamido)phenyl)
picolinamide)
To a solution of 4-bromopicolinic acid (1.1 g, 5.5 mmol) in THF (5
mL) and DCM (5 mL) and DMF (1.0 mL) was added oxalic chloride (0.47
mL, 5.5 mmol). The resulting solution was stirred for 2 h at rt. After
concentration in vacuo, the residue was taken up in DCM (10 mL) and a
solution of compound 2 (1.5 g, 5.0 mmol) and TEA (1.5 mL, 11 mmol) in
DCM (10 mL) was added. The resulting mixture was stirred overnight
and diluted with DCM (50 mL) and 1 M HCl (50 mL). The solids were
collected by filtration, rinsed with water and DCM to obtain the product
as a white solid (1.9 g, 79%). 1H NMR (400 MHz, DMSO‑d6): δ = 10.52
(s, 1H), 10.29 (s, 1H), 8.74 (d, 1H, J = 5.3 Hz), 8.27 (m, 3H), 8.17 (d, 1H,
J = 2.1 Hz), 7.96 (d, 1H, J = 7.8 Hz), 7.86 (dd, 1H, J = 2.1, 5.3 Hz), 7.80
(t, 1H, J = 7.8 Hz), 7.62 (dd, 1H, J = 2.2, 8.2 Hz), 7.27 (d, 1H, J = 8.4
Hz), 2.29 (s, 3H) 13C NMR (101 MHz, DMSO‑d6): δ = 163.8, 160.9,
151.4, 150.2, 145.0, 137.0, 135.7, 135.6, 131.9, 130.2, 129.7, 129.1 (q,
J = 32.0 Hz), 128.1 (q, J = 3.7 Hz), 126.9, 126.3, 124.0 (q, J = 272.6
Hz), 124.2 (q, J = 3.8 Hz), 122.3, 117.7, 115.8, 17.0; ESI-HRMS: m/z
calculated for C21H15BrF3N3NaO2: 500.0193; found 500.0201 [M +
Na]+.
5.1.8. (5-(1-(2-fluoroethyl)-1H-pyrazol-4-yl)-N-(2-methyl-5-(3-
(trifluoromethyl)benzamido)phenyl)nicotinamide)
A mixture of compound 3 (95 mg, 0.20 mmol), compound 7 (42 mg,
0.20 mmol), Pd(PPh3)4 (23 mg, 20 µmol) and CsF (50 mg, 0.33 mmol) in
MeOH/THF (1:1, 3 mL) was refluxed for 16 h. After concentration in
vacuo and flash column chromatography (EA/hexanes 3:1), the product
was obtained as a yellow solid (75 mg, 73%). 1H NMR (400 MHz,
DMSO‑d6): δ = 10.51 (s, 1H), 10.17 (s, 1H), 9.06 (s, 1H), 8.96 (s, 1H),
8.50 (m, 2H), 8.32 (m, 2H), 8.16 (s, 1H), 7.95 (m, 2H), 7.79 (t, 1H, J =
7.8 Hz), 7.64 (d, 1H, J = 8.2 Hz), 7.31 (d, 1H, J = 8.2 Hz), 4.82 (dt, 2H, J
= 47.3, 4.7 Hz), 4.50 (dt, 2H, J = 27.8, 4.7 Hz), 2.26 (s, 3H); 13C NMR
(101 MHz, DMSO‑d6): δ = 164.4, 164.3, 149.0, 146.6, 137.5, 137.3,
136.4, 136.2, 132.3, 131.9, 131.5, 130.8, 130.7, 130.2, 129.8, 129.6 (q,
J = 32.8 Hz), 129.1, 128.7, 128.6 (q, J = 3.8 Hz), 124.7 (q, J = 3.8 Hz),
124.4 (q, J = 272.4 Hz), 119.2, 119.0, 118.5, 81.9 (d, J = 168.8 Hz),
52.6 (d, J = 19.9 Hz); ESI-HRMS: m/z calculated for C26H21F4N5NaO2:
534.1529; found 534.1524 [M + Na]+.
5.1.5. (5-(1-methyl-1H-pyrazol-4-yl)-N-(2-methyl-5-(3-(trifluoromethyl)
benzamido)phenyl)nicotinamide)
A solution of compound 3 (96 mg, 0.20 mmol), 1-methylpyrazole-4-
boronic acid pinacol ester (42 mg, 0.20 mmol), Pd(PPh3)4 (23 mg, 20
µmol) and CsF (50 mg, 0.33 mmol) in MeOH/DMF (1:1, 2 mL) was
reacted for 16 h at 70 ◦C. After concentration in vacuo and flash column
chromatography (hexanes/EA 1:3 -> 0:1) the product was obtained as a
white solid (65 mg, 68%). 1H NMR (500 MHz, CDCl3): δ = 9.29 (s, 1H),
8.90 (m, 2H), 8.67 (s, 1H), 8.17 (s, 1H), 8.05 (s, 1H), 7.94 (d, 1H, J = 7.8
Hz), 7.81 (s, 1H), 7.72 (s, 1H), 7.64 (m, 2H), 7.42 (t, 1H, J = 7.8 Hz),
7.24 (d, 1H, J = 8.3 Hz), 6.90 (d, 1H, J = 8.4 Hz), 3.85 (s, 3H), 1.93 (s,
3H); 13C NMR (101 MHz, DMSO‑d6): δ = 164.4, 164.3, 149.0, 146.4,
137.3, 137.0, 136.4, 136.2, 132.3, 131.4, 130.8, 130.7, 130.2, 129.8,
129.5, 129.1, 128.8, 128.5 (q, J = 3.8 Hz), 124.7 (q, J = 3.8 Hz), 124.4
(q, J = 272.4 Hz), 119.2, 119.0, 118.4, 39.2, 17.9; ESI-HRMS: m/z
calculated for C25H20F3N5NaO2: 502.1467; found 502.1461 [M + Na]+.
5.1.9. (N3-methyl-N5-(2-methyl-5-(3-(trifluoromethyl)benzamido)
phenyl)pyridine-3,5-dicarboxamide)
To a solution of compound 3 (95 mg, 0.20 mmol), Pd(OAc)2 (2.2 mg,
25 µmol), xantphos (12 mg, 50 µmol), NaOAc (41 mg, 0.50 mmol) in
dioxane (4 mL) was added a solution of 2,4,6-trichlorophenyl formate
(77 mg, 0.30 mmol) in toluene (1 mL). The resulting solution was heated
◦
at 80 C in a closed vial for 16 h. After dilution with EA (10 mL) the
mixture was filtered. The filtrate was concentrated in vacuo and resus-
pended in DMF (5 mL). Subsequently, TEA (0.28 mL, 2.0 mmol) and
methylamine⋅HCl (0.13 g, 2.0 mmol) were added and the mixture was
reacted for 3 h at rt. After dilution with EA (50 mL), the organic fraction
was washed with 1 M HCl (50 mL) and brine (50 mL). After drying on
Na2SO4, filtration and concentration, the product was purified using
flash column chromatography (2% MeOH in EtOAc) to yield the product
as a white solid (32 mg, 35%). 1H NMR (400 MHz, DMSO‑d6): δ = 10.50
(s, 1H), 10.29 (s, 1H), 9.24 (s, 1H), 9.16 (s, 1H), 8.84 (d, 1H, J = 4.7 Hz),
8.71 (s, 1H), 8.30 (m, 2H), 7.98 (d, 1H, J = 7.8 Hz), 7.88 (s, 1H), 7.79 (t,
1H, J = 7.8 Hz), 7.61 (d, 1H, J = 8.4 Hz), 7.30 (d, 1H, J = 8.2 Hz), 2.85
(d, 3H, J = 4.3 Hz), 2.24 (s, 3H); 13C NMR (101 MHz, DMSO‑d6): δ =
164.6, 163.9, 163.5, 150.6, 136.9, 135.9, 135.7, 134.3, 131.9, 130.4,
129.9, 129.8, 129.7, 129.3, 129.0, 128.2, 128.1, 124.2 (q, J = 3.8 Hz),
124.0 (q, J = 272.4 Hz), 118.7, 118.6, 26.3, 17.5; ESI-HRMS: m/z
calculated for C23H19F3N4NaO3: 479.1307; found: 479.1303 [M + Na]+.
5.1.6. (2-(1-methyl-1H-pyrazol-4-yl)-N-(2-methyl-5-(3-(trifluoromethyl)
benzamido)phenyl)isonicotinamide)
A solution of compound 4 (96 mg, 0.20 mmol), 1-methylpyrazole-4-
boronic acid pinacol ester (42 mg, 0.20 mmol), Pd(PPh3)4 (23 mg, 20
µmol) and CsF (50 mg, 0.33 mmol) in THF/DMF (1:1, 3 mL) was reacted
for 16 h at 70 ◦C. After concentration in vacuo and flash column chro-
matography (2% MeOH in EA) the product was obtained as a white solid
(85 mg, 88%). 1H NMR (400 MHz, DMSO‑d6): δ = 10.49 (s, 1H), 10.19
(s, 1H), 8.68 (d, 1H, J = 5.1 Hz), 8.35 (s, 1H), 8.29 (m, 2H), 8.10 (s, 1H),
8.05 (s, 1H), 7.96 (d, 1H, J = 7.8 Hz), 7.87 (s, 1H), 7.77 (t, 1H, J = 7.8
Hz), 7.62 (m, 2H), 7.29 (d, 1H, J = 8.2 Hz), 3.89 (s, 3H), 2.23 (s, 3H); 13
C
NMR (101 MHz, DMSO‑d6): δ = 164.0, 163.9, 152.5, 150.1, 142.4,
8