C([O:3][C:4](=[O:19])[C:5]1[CH:10]=[CH:9][CH:8]=[C:7]([NH:11][C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH:6]=1)C.[Li+].[OH-]>C1COCC1>[C:15]([O:14][C:12]([NH:11][C:7]1[CH:6]=[C:5]([CH:10]=[CH:9][CH:8]=1)[C:4]([OH:19])=[O:3])=[O:13])([CH3:18])([CH3:16])[CH3:17]To the crude 3-tert-butoxycarbonylamino-benzoic acid ethyl ester (˜2.0 g, 0.00754 mmol) added THF (15 mL), and 0.5M LiOH (15 mL). The mixture was heated for two hours at 75° C. and the THF was removed in vacuo after cooling. The precipitate was filtered from the remaining mixture and the filtrate was transferred to a separatory funnel. The aqueous layer was washed with dichloromethane (3×) and was acidified to pH˜5 using 1M HCl. The product was then extracted with ethyl acetate, washed with water, saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated. 730 mg of 3-tert-Butoxycarbonylamino-benzoic acid (white solid) was isolated. 1H NMR (DMSO-d6) δ (ppm): 9.58 (s, 1H), 8.16 (s, 1H), 7.63 (d, 1H), 7.54 (d, 1H), 7.37 (t, 1H), 1.49 (s, 9H)
불러오는 중…