反応 #511485

反応方程式

4-hydroxybenzoic acid

pyridinium p-toluenesulphonic acid

3,4-dihydro-2H-pyran

→

4-(tetrahydro-2H-pyran-2-yloxy)benzoic acid

溶媒

diethylether

反応条件

後処理

1. 1
   workup.ADDITIONwise added
2. 2
   workup.ADDITIONAfter complete addition
3. 3
   ろ過the white precipitate was filtered off
4. 4
   洗浄washed twice with 100 ml of +4° C.
5. 5
   温度pre-cooled diethylether
6. 6
   その他dried

実験手順

To an ice-cooled mixture of 4-hydroxybenzoic acid (13.81 g) in 250 ml of diethylether containing 1.98 g of pyridinium p-toluenesulphonic acid, 3,4-dihydro-2H-pyran (16 g) was drop wise added. After complete addition stirring was continued at temperature below +8° C. for 4 h and the white precipitate was filtered off, washed twice with 100 ml of +4° C. pre-cooled diethylether and dried to give nearly pure 4-(tetrahydro-2H-pyran-2-yloxy)benzoic acid as white powder.

出典