反応 #2507828

反応方程式

N-formylpiperidine

n-butyllithium

7-bromo-6-fluoro-3-pentylchroman

hydrochloric acid

→

6-fluoro-3-pentylchroman-7-carbaldehyde

溶媒

THF

n-hexane

THF

water

反応条件

後処理

1. 1
   抽出extracted three times with MTB ether
2. 2
   洗浄phases are washed with water and sat. sodium chloride soln
3. 3
   乾燥and dried over sodium sulfate
4. 4
   その他the solvent is removed in vacuo
5. 5
   その他the residue is recrystallised from heptane at −25° C.

実験手順

15.5 g (51.5 mmol) of 7-bromo-6-fluoro-3-pentylchroman are dissolved in 85 ml of THF, and 35 ml (55.7 mmol) of a 15 percent solution of n-butyllithium in n-hexane are slowly added at −70° C. After 1 h, 6.3 ml (56.7 mmol) of N-formylpiperidine in 15 ml of THF are added dropwise, and the mixture is stirred for 1 h. The batch is subsequently allowed to thaw, added to water, acidified using dil. hydrochloric acid and extracted three times with MTB ether. The combined org. phases are washed with water and sat. sodium chloride soln. and dried over sodium sulfate, the solvent is removed in vacuo, and the residue is recrystallised from heptane at −25° C., giving 6-fluoro-3-pentylchroman-7-carbaldehyde as colourless crystals (Rf=0.4; 1-chlorobutane).

出典