Reaktion #90558

Reaktionsgleichung

3,5-dibromo pyridine

isopropyl magnesium chloride

Hexafluoroacetone

→

2-(5-bromopyridin-3-yl)-1,1,1,3,3,3-hexafluoropropan-2-ol

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGcontinued stirring for another 2 h
2. 2
   SonstigeAfter completion of the starting materials, the reaction was quenched with saturated ammonium chloride solution
3. 3
   SonstigeThe organic layer was separated
4. 4
   Extraktionaqueous phase was extracted again with diethyl ether
5. 5
   Trocknenthe combined organic layer was dried over sodium sulphate
6. 6
   Einengenconcentrated

Vorschrift

To a stirred solution of 3,5-dibromo pyridine 257 (1.09 g, 4.60 mmol) in dry THF cooled to 0° C., was added isopropyl magnesium chloride (2.4 mL, 4.8 mmol) drop wise while stirring for 10 min. Hexafluoroacetone (CF3—CO—CF3) 244 was added to the resulting reaction and continued stirring for another 2 h. After completion of the starting materials, the reaction was quenched with saturated ammonium chloride solution. The organic layer was separated and aqueous phase was extracted again with diethyl ether, the combined organic layer was dried over sodium sulphate and concentrated to get the crude 2-(5-bromopyridin-3-yl)-1,1,1,3,3,3-hexafluoropropan-2-ol 258. The crude was purified through silica gel by using 100-200 mesh silica gel by eluting the compound at 20:5 ethyl acetate in hexane as thick oil of compound 258.

Quelle