[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[NH:8][C:9](=[O:15])[O:10][C:11]([CH3:14])([CH3:13])[CH3:12].C([Li])(C)(C)C.[B:21](OC)([O:24]C)[O:22]C.[OH-].[Na+].Cl>O1CCCC1.C(OCC)(=O)C>[C:11]([O:10][C:9]([NH:8][C:3]1[C:2]([F:1])=[CH:7][CH:6]=[CH:5][C:4]=1[B:21]([OH:24])[OH:22])=[O:15])([CH3:12])([CH3:14])[CH3:13]To a solution of tert-butyl 2-fluorophenylcarbamate (from step 1) (1.0 eq.) in tetrahydrofuran (0.25 M) at −78° C. under N2 atmosphere was added dropwise 1.7 M tert-butyllithium (2.4 eq.). The reaction was warmed to −40° C. slowly over 2 hours, and neat trimethyl borate (3.8 eq.) was added. The reaction was warmed to room temperature over 30 minutes. An aqueous solution of 1N NaOH was slowly added to the reaction and stirred for 15 minutes. The mixture was poured into ethyl acetate and acidified with 3N HCl to dissolve the solids. The aqueous layer was extracted twice with ethyl acetate, and the combined organic layers were washed with brine, dried over anhydrous MgSO4, and concentrated en vacuo. The resulting solids were stirred in 1:1 ether/hexane, filtered, and dried. The solids were carried onto the next step without further purification.
불러오는 중…
