[Li+].C[Si]([N-][Si](C)(C)C)(C)C.[F:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=1[CH2:18][C:19]([O:21][CH3:22])=[O:20].[Cl:23][C:24]1[C:25]([C:31](Cl)=[O:32])=[N:26][CH:27]=[C:28]([Cl:30])[CH:29]=1.[Cl-].[NH4+]>CCCCCC.C1COCC1.O>[Cl:23][C:24]1[C:25]([C:31](=[O:32])[CH:18]([C:13]2[CH:14]=[CH:15][CH:16]=[CH:17][C:12]=2[F:11])[C:19]([O:21][CH3:22])=[O:20])=[N:26][CH:27]=[C:28]([Cl:30])[CH:29]=128.5 ml (28.5 mmol) of a 1 M solution of LiHMDS in hexane are added to 50 ml of THF at −78° C. A solution of 4.00 g (23.8 mmol) of methyl (2-fluorophenyl)acetate in 10 ml of THF is then added dropwise. The mixture is stirred at −78° C. for 1 h and then 6.00 g (28.5 mmol) of 3,5-dichloro-pyridine-2-carbonyl chloride are added in portions. After a further hour, the mixture is allowed to reach RT and saturated ammonium chloride solution is added dropwise. The mixture is diluted with water and extracted with ethyl acetate. The organic phase is washed with saturated sodium chloride solution and dried over sodium sulfate. The residue after concentration in vacuo is purified by chromatography on silica gel (eluent: dichloromethane/methanol 50:1). 4.46 g (46% of theory) of the desired compound are obtained as a yellowish oil.
불러오는 중…
