[CH2:1]([Mg]I)[CH3:2].[Br:5][C:6]1[CH:15]=[CH:14][C:9]([C:10]([O:12]C)=O)=[C:8]([F:16])[CH:7]=1.[NH4+].[Cl-]>C(OCC)C.CC(O[Ti](OC(C)C)(OC(C)C)OC(C)C)C>[Br:5][C:6]1[CH:15]=[CH:14][C:9]([C:10]2([OH:12])[CH2:2][CH2:1]2)=[C:8]([F:16])[CH:7]=1
To a stirred solution of Ti(OiPr)4 (44.68 mL, 141.63 mmol, 1 eq) in diethyl ether (250 mL) was added freshly prepared ethyl magnesium iodide (212.44 mL, 424.89 mmol, 3 eq) in diethyl ether (220 mL) at −78° C. for 45 min. The reaction mixture was stirred for 90 min at −78° C., then methyl 4-bromo-2-fluorobenzoate (33.0 g, 141.63 mmol, 1.0 eq) was added and the mixture allowed to stir at RT for 16 h. Saturated aqueous NH4Cl (30 mL) was added and the mixture passed through celite pad. The ether layer was separated, washed with 1 N HCl (250 mL), brine (500 mL), water (750 mL), dried over MgSO4 and the solvent evaporated. The resulting residue was purified by CC using PE/EtOAc (19:1) as eluent to get 1-(4-bromo-2-fluorophenyl)cyclopropanol (9.01 g, 28%; TLC system: PE/EtOAc (9:1), Rf: 0.3).
Wird geladen…
