Reaktion #657309

Reaktionsgleichung

3-(4-fluorophenyl)-1H-pyrazol-5-ol

K2CO3

2,2-difluoropropane-1,3-diyl dimethanesulfonate

→

6,6-difluoro-2-(4-fluorophenyl)-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine

Ausbeute 56.0%

Lösungsmittel

DMF

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with diethyl ether
2. 2
   TrocknenThe organic layer was dried over anhydrous sodium sulphate
3. 3
   Einengenconcentrated
4. 4
   Sonstigeto get the crude product
5. 5
   SonstigePurification by column chromatography over silica gel (eluent 5-10% ethyl acetate in petrol ether)

Vorschrift

To a solution of 3-(4-fluorophenyl)-1H-pyrazol-5-ol (4 g, 22.47 mmol) in DMF (30 mL) was added K2CO3 (12.4 g, 89.88 mmol) and 2,2-difluoropropane-1,3-diyl dimethanesulfonate (9 g, 33.7 mmol) at room temperature and then stirred for 16 h at 60° C. The progress of the reaction was monitored by TLC. Thereafter, the reaction mixture was diluted with cold water and extracted with diethyl ether. The organic layer was dried over anhydrous sodium sulphate and concentrated to get the crude product. Purification by column chromatography over silica gel (eluent 5-10% ethyl acetate in petrol ether) yielded 6,6-difluoro-2-(4-fluorophenyl)-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine (3.2 g, 56%) as an off-white solid.

Quelle