2-(2-Fluorophenyl)-1,5-dimethyl-4-nitro-1H-pyrazol-3(2H)-one → 4-Amino-2-(2-fluorophenyl)-1,5-dimethyl-1H-pyrazol-3(2H)-one

Temperature

65 °C

2-(2-Fluorophenyl)-1,5-dimethyl-4-nitro-1H-pyrazol-3(2H)-one (208 g, 828 mmol) and 10% Pd/C (25 g, 235 mmol) in MeOH (3000 ml) was subjected to hydrogenation over 98 hrs at 0.1 bar at RT. The resulting mixture was filtered over a pad of Celite® (filter material), washed with MeOH (1000 ml) and the filtrate was evaporated to dryness. To the solid was added DCM (300 ml) and this was heated at 65° C., followed by addition of toluene (900 ml). The DCM was removed under reduced pressure and the resulting mixture was allowed to cool to RT with stirring and left to stand at RT overnight. The mixture was filtered, washing with 1:1 toluene:heptane (200 ml) and heptane (800 ml) and dried under v to give the title compound as light yellow crystals.

1. filtrationThe resulting mixture was filtered over a pad of Celite® (filter material)
2. washwashed with MeOH (1000 ml)
3. customthe filtrate was evaporated to dryness
4. additionTo the solid was added DCM (300 ml)
5. additionfollowed by addition of toluene (900 ml)
6. customThe DCM was removed under reduced pressure
7. temperatureto cool to RT
8. waitleft
9. filtrationThe mixture was filtered
10. washwashing with 1:1 toluene
11. dry with materialheptane (200 ml) and heptane (800 ml) and dried under v

ORD record

ord-99464e0022274c10970026c5cb34cac6

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09403833B2