反应详情

LiOH (495.9 μL of 1 M aq solution, 0.4959 mmol) was added to a suspension of methyl 4-[5-amino-6-(5-phenyl-1,3,4-oxadiazol-2-yl)pyrazin-2-yl]-3-(difluoromethyl)benzoate (70 mg, 0.1653 mmol) in THF (5 mL) and methanol (2 mL). The reaction mixture was stirred for 4 h at room temperature and then concentrated in vacuo. The residue was acidified to pH2 by the addition of 1M HCl. A precipitate formed which was then filtered and washed with water, ethylacetate and ether. The solid was taken up in DMF (2 mL) and TBTU (79.63 mg, 0.2480 mmol) and DIPEA (64.09 mg, 86.37 μL, 0.4959 mmol) added followed by N-methylmethanamine (495.9 μL of 1 M, 0.4959 mmol) in THF. The resulting mixture was stirred at room temperature for 2 h, diluted with ethylacetate (5 mL), washed with water (2×5 mL) and concentrated in vacuo. The residue was purified by reverse phase preparative HPLC [Waters Sunfire C18, 10 mM, 100 Å column, gradient 10%-95% B (solvent A: 0.05% TFA in water; solvent B: CH3CN) over 16 minutes at 25 mL/min]. Product fractions were freeze dried to leave the product as a solid (29.6 mg, 40% yield); 1H NMR (400.0 MHz, DMSO) d 3.0 (d, 6H), 7.6-7.7 (m, 4H), 7.82 (s, 1H), 7.9 (d, 2H), 8.15-8.18 (m, 2H) and 8.7 (s, 1H) ppm; MS (ES+) 437.2

1. concentrationconcentrated in vacuo
2. additionThe residue was acidified to pH2 by the addition of 1M HCl
3. customA precipitate formed which
4. filtrationwas then filtered
5. washwashed with water, ethylacetate and ether
6. stirringThe resulting mixture was stirred at room temperature for 2 h
7. washwashed with water (2×5 mL)
8. concentrationconcentrated in vacuo
9. customThe residue was purified by reverse phase preparative HPLC [Waters Sunfire C18, 10 mM, 100 Å column, gradient 10%-95% B (solvent A: 0.05% TFA in water; solvent B: CH3CN) over 16 minutes at 25 mL/min]
10. customdried