反応 #6968

反応方程式

3-butenal diethyl acetal

9-BBN

Na2CO3

3-bromo-4-fluoro-N-cyclopropylbenzamide

→

N-cyclopropyl-3-(4,4-diethoxybutyl)-4-fluorobenzamide

収率 93.4%

溶媒

ethyl acetate

EtOH

benzene

反応条件

後処理

1. 1
   濃縮The mixture was concentrated and to the residue
2. 2
   温度The mixture was then cooled to RT
3. 3
   洗浄washed with water
4. 4
   その他The organic layer was separated
5. 5
   濃縮concentrated
6. 6
   その他The residue was purified by column chromatography (SiO2; EtOAc/hexane 1:3)

実験手順

A solution of 3-butenal diethyl acetal (144 mg, 1 mmol) and 9-BBN (0.5 M in THF, 2.2 mL, 1.1 mmol) was stirred at RT for 1 h. The mixture was concentrated and to the residue were added benzene (2 mL), EtOH (1 mL), aqueous Na2CO3 solution (2M, 1 mL), 3-bromo-4-fluoro-N-cyclopropylbenzamide (127 mg, 0.5 mmol) and Pd(Ph3P)4 (40 mg). The resulting mixture was stirred at 80° C. for 2 h. The mixture was then cooled to RT and diluted with ethyl acetate (10 mL) and washed with water. The organic layer was separated and concentrated. The residue was purified by column chromatography (SiO2; EtOAc/hexane 1:3) to afford N-cyclopropyl-3-(4,4-diethoxybutyl)-4-fluorobenzamide (151 mg, 93%). This material was dissolved in acetone (1 mL) and 3 N HCl solution (0.2 mL) and stirred at RT for 1 h. The mixture was neutralized with NaHCO3 solution and extracted with ethyl acetate (3×5 mL). The organic layer was dried and concentrated to afford N-cyclopropyl-4-fluoro-3-(4-oxo-butyl)-benzamide (110 mg, 94%).

出典