[OH:1][B:2]1[C:6]2[CH:7]=[C:8](/[CH:11]=[N:12]/O)[CH:9]=[CH:10][C:5]=2[C:4]([CH3:15])([CH3:14])[O:3]1.CO>CC(O)=O.[Zn]>[NH2:12][CH2:11][C:8]1[CH:9]=[CH:10][C:5]2[C:4]([CH3:15])([CH3:14])[O:3][B:2]([OH:1])[C:6]=2[CH:7]=1To a solution of crude compound (E)-1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-6-carbaldehyde oxime (47.4 mmol) in AcOH (60 mL) at rt was added zinc dust (12.3 g, 190 mmol). The reaction mixture was stirred at 40° C. for 4 h under argon atmosphere. Methanol was added and the mixture was filtered over Celite. The filtrate was concentrated and dissolved in ethyl acetate. The organic layer was washed with water. The water layer was lyophilized to give the crude compound 6-(aminomethyl)-3,3-dimethylbenzo[c][1,2]oxaborol-1(3H)-ol as a light yellow solid. It was used in next step without further purification. MS: m/z=192.0 (M+1, ESI+).
불러오는 중…