Réaction #657309

Équation de réaction

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

Rendement 56.0%

Solvants

DMF

water

Conditions de réaction

Traitement

1. 1
   Extractionextracted with diethyl ether
2. 2
   SéchageThe organic layer was dried over anhydrous sodium sulphate
3. 3
   Concentrationconcentrated
4. 4
   Autreto get the crude product
5. 5
   AutrePurification by column chromatography over silica gel (eluent 5-10% ethyl acetate in petrol ether)

Mode opératoire

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.

Source