Reaktion #58690

Reaktionsgleichung

Intermediate 44

2-amino-6-fluoro-benzoic acid N′-(2-fluoro-phenyl)-hydrazide

sodium nitrite

→

4-fluoro-1-(2-fluoro-phenyl)-1H-indazol-3-ol

Ausbeute 95.0%

Lösungsmittel

EtOH H2O

water

HCl

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated
2. 2
   Temperaturto reflux for 3 hours
3. 3
   workup.STIRRINGstirred at room temperature for 18 hours
4. 4
   FiltrationThe solid was filtered
5. 5
   Waschenrinsed with water
6. 6
   Sonstigedried

Vorschrift

Intermediate 44 (2.182 g, 8.289 mmol) was suspended in 1M HCl (20 ml), cooled to 0° C. and treated dropwise with a solution of sodium nitrite (1.144 g, 16.58 mmol) in water (7 ml). The mixture was stirred for 10 minutes at 0° C., diluted with 1:1 EtOH/H2O (30 ml) and heated to reflux for 3 hours, then stirred at room temperature for 18 hours. The solid was filtered, rinsed with water and dried to afford 1.939 g (95%) of 4-fluoro-1-(2-fluoro-phenyl)-1H-indazol-3-ol (Intermediate 45) as a tan solid. MS (APCI): (M+1)=247.1, (M−1)=245.0.

Quelle