反応 #1960498

反応方程式

hydrochloric acid

trimethyl borate

hydrogen peroxide

7,8-difluoro-2-(4-propylcyclohexyl)-1,2,3,4-tetrahydronaphthalene

n-BuLi

→

3,4-difluoro-6-(4-propylcyclohexyl)-5,6,7,8-tetrahydronaphthalen-2-ol

溶媒

Water

acetic acid

THF

反応条件

後処理

1. 1
   温度The mixture is warmed to 30° C.
2. 2
   workup.ADDITIONWhen the addition
3. 3
   抽出The solution is extracted a number of times with MTBE
4. 4
   洗浄the combined organic phases are washed successively with water, sat. sodium chloride soln
5. 5
   その他The solution is dried
6. 6
   その他evaporated to dryness
7. 7
   その他The crude product is purified by column chromatography (SiO2, toluene)
8. 8
   その他The further purification
9. 9
   その他is carried out by crystallisation from n-heptane

実験手順

77.0 g (about 0.26 mol) of crude 7,8-difluoro-2-(4-propylcyclohexyl)-1,2,3,4-tetrahydronaphthalene are initially introduced in 500 ml of THF, and 200.0 ml (0.32 mol) of n-BuLi (15% soln. in hexane) are added at −70° C. After 3 h at this temperature, 37.0 ml (0.33 mol) of trimethyl borate are added dropwise, the batch is warmed to 0° C., and 80 ml of dilute acetic acid (about 30%) are added. The mixture is warmed to 30° C., and 70 ml of hydrogen peroxide solution (35%) are carefully added. When the addition is complete, the mixture is stirred at RT for 2 h. Water is added, and the batch is acidified using dil. hydrochloric acid. The solution is extracted a number of times with MTBE, and the combined organic phases are washed successively with water, sat. sodium chloride soln. and ammonium iron(II) sulfate soln. The solution is dried using sodium sulfate and evaporated to dryness. The crude product is purified by column chromatography (SiO2, toluene). The further purification is carried out by crystallisation from n-heptane, giving 3,4-difluoro-6-(4-propylcyclohexyl)-5,6,7,8-tetrahydronaphthalen-2-ol as a colourless solid.

出典