Ethyl chloroformate → 5-Fluoro-3H-spiro[benzofuran-2,4'-piperidine]
Reaction equation
ClC(OCC)=O.C([N:14]1[CH2:19][CH2:18][C:17]2([CH2:23][C:22]3[CH:24]=[C:25]([F:28])[CH:26]=[CH:27][C:21]=3[O:20]2)[CH2:16][CH2:15]1)C1C=CC=CC=1>C1(C)C=CC=CC=1>[F:28][C:25]1[CH:26]=[CH:27][C:21]2[O:20][C:17]3([CH2:16][CH2:15][NH:14][CH2:19][CH2:18]3)[CH2:23][C:22]=2[CH:24]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Ethyl chloroformate (65.6 mg, 0.604 mmol) was added to a solution of 1′-benzyl-5-fluoro-3H-spiro[1-benzofuran-2,4′-piperidine] (150 mg, 0.504 mmol) in toluene (2 mL) and the reaction mixture was refluxed overnight. The reaction mixture was cooled to room temperature, diluted by addition of toluene, washed successively with aqueous sodium hydrogencarbonate (NaHCO3) and water. The organic layer was dried over sodium sulphate (Na2SO4) filtered and concentrated in vacuo. The residue was dissolved in ethanol (3.5 mL), aqueous potassium hydroxide (KOH) (800 mg KOH in 0.8 mL water) was added and the reaction mixture was kept on stirring at reflux overnight, cooled to room temperature, extracted with ethyl acetate. The organic layer was well washed with water, dried over sodium sulphate (Na2SO4), filtered and concentrated. The residue was purified by HPLC (10% acetonitrile (CH3CN)-55% CH3CN in water containing 0.1% ammonium hydroxide, NH4OH) to give the titled compound (49 mg).