芳胺boc保护？2-Aminofluorene (20 g, 110 mmol) is suspended in a mixture of dioxaneH2O (2:1) (200 mL) and 2 N NaOH (60 mL) in an ice bath with magnetic stirring. Boc2O (26.5 g, 121 mmol, 1.1 equiv) is then added and the stirring is continued at 25◦C. The evolution of the reaction is followed by TLC and the pH is maintained between 9–10 by addition of 2 N NaOH. If, after 24 h, TLC analysis still shows the presence of 2- aminofluorene , Boc2O (5 g, 22,8 mmol, 0.21 equiv) is added and the reaction is continued until the total disappearance of the starting product. The suspension is acidified with 1 M KHSO4 to pH 3. The solid is filtered and washed with cold H2O (50 mL), dioxane-H2O (2:1) (50 mL), hexane (50 mL), and dried over P2O5. The product, a pale yellow powder (30.1 g, 97% yield) (12), is shown to be pure by TLC (Rf = 0.70), 1H-NMR and FAB-MS . ——SynComm-2001-31-225查看更多
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