反応 #71529

反応方程式

3,5-dibromobenzaldehyde

tert-butoxide

(1,3-dioxolan-2-ylmethyl)tri-n-butylphosphine bromide salt

HCl

→

3-(3′,5′-dibromophenyl)-2-propenal

溶媒

ether

反応条件

後処理

1. 1
   温度The reaction was gradually warmed to room temperature
2. 2
   workup.STIRRINGstirred at room temperature for 21 h
3. 3
   その他The two layers were separated
4. 4
   抽出The aqueous layer was extracted with ether (3×200 cm3)
5. 5
   洗浄washed with brine (1×300 cm3)
6. 6
   乾燥dried over anhydrous magnesium sulfate
7. 7
   その他The solvents were completely removed
8. 8
   その他to leave a yellow solid
9. 9
   その他The solid was purified by column chromatography of silica gel
10. 10
    その他ethyl acetate-light petroleum (40-60° C.)
11. 11
    その他to give 3.36 g (19%) of A-1 as a colourless solid

実験手順

3,5-dibromobenzaldehyde (16.1 g, 61.0 mmol) was added to a cold (ice-water bath) solution of tert-butoxide (13.0 g, 116 mmol), (1,3-dioxolan-2-ylmethyl)tri-n-butylphosphine bromide salt (4.5 M, 32 cm3, 144 mmol) in 400 cm3 of ether under argon. The mixture was stirred at 0-2° C. for 2 h. 1.0 M HCl(aq) (300 cm3) was added to the mixture. The reaction was gradually warmed to room temperature and stirred at room temperature for 21 h. The two layers were separated. The aqueous layer was extracted with ether (3×200 cm3). The organic layer and the ether extracts were combined, washed with brine (1×300 cm3) and dried over anhydrous magnesium sulfate. The solvents were completely removed to leave a yellow solid. The solid was purified by column chromatography of silica gel using ethyl acetate-light petroleum (40-60° C.) as eluent to give 3.36 g (19%) of A-1 as a colourless solid; δH(200 MHz; CDCl3) 6.68 (1 H, dd, J 7.4 & 16 Hz, vinylH), 7.33 (1 H, d, J 16 Hz, vinylH), 7.33 (2 H, m, ArH), 7.63 (1 H, m, ArH), and 9.72 (1 H, d, J 7.6 Hz, CHO); m/z [CI(NH3)] 306, 308, 310 (MNH4+), and 288, 290, 292 (M+).

出典