Diethyl Ether → (S)-4-(1-Boc-amino-ethyl)-benzoic acid

関与物質

反応条件

反応手順

To a solution of tert-butyl [(1S)-1-(4-bromophenyl)ethyl]carbamate from Example 1, Step 7 (91.7 g, 305 mmol) in THF (1.5 L)/ether (300 mL) at −20° C. was added methyllithium (1.6M in ether, 229 mL, 366 mmol) and the mixture was slowly warmed to 0° C. and stirred for 30 min. and then cooled to −72° C. (internal temperature). n-Butyllithium (2.5M in hexanes, 146 mL, 366 mmol) was added dropwise and the mixture was stirred at −72° C. for 30 min. Excess CO2 gas was bubbled into the reaction mixture (white solid formation) and the suspension was allowed to warm in air for 30 min. and then to it was added 18 mL of acetic acid. The slurry was stirred at r.t. for 1 h and then filtered. The solid was collected and redissolved in acetic acid (50 mL), ethyl acetate and water and extracted with ethyl acetate. The organic layers were washed with water, dried over Na2SO4 and filtered. The crude product was washed with ether and dried under vacuum to give the desired product.

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