反応 #51455

反応方程式

methyl 2(R/S)-(tert-butoxycarbonyl)amino-3,3-dimethyl-4-pentenoate

trifluoroacetic acid

→

methyl 2(R/S)-amino-3,3-dimethyl-4-pentenoate

収率 75.8%

溶媒

dichloromethane

反応条件

後処理

1. 1
   濃縮the solution was concentrated
2. 2
   workup.DISSOLUTIONthe residue was dissolved in 100 mL of dichloromethane
3. 3
   洗浄washed with sat. aq. sodium bicarbonate (50 mL)
4. 4
   乾燥The organic layer was dried over sodium sulfate
5. 5
   濃縮concentrated

実験手順

To a solution of methyl 2(R/S)-(tert-butoxycarbonyl)amino-3,3-dimethyl-4-pentenoate (4.97 g, 19.3 mmol) in 50 mL of dichloromethane at 0° C. was added 16.5 mL of trifluoroacetic acid. After 2 hours, the solution was concentrated and the residue was dissolved in 100 mL of dichloromethane and washed with sat. aq. sodium bicarbonate (50 mL). The organic layer was dried over sodium sulfate and concentrated to give methyl 2(R/S)-amino-3,3-dimethyl-4-pentenoate (2.30 g), which was dissolved in 50 mL of dichloromethane and cooled to 0° C. Triethylamine (8.1 mL, 58 mmol) was added, followed by addition of 4-(4-fluorophenoxy)benzenesulfonyl chloride (6.71 g, 21.3 mmol). The reaction was allowed to warm to room temperature and stirred for 18 hours and then washed 3 N hydrochloric acid (125 mL), dried over sodium sulfate and concentrated. The residue was purified by chromatography on silica gel, eluting with 20% ethyl acetate in hexane, to yield 4.41 g (61%) of methyl 2(R/S)-[4-(4-fluorophenoxy)benzenesulfonyl]amino-3,3-dimethyl4-pentenoate as a white solid.

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