反応 #984028

反応方程式

trimethoxytoluene

3,6-difluoro-2-methylbenzoic acid

3,4,5-trimethoxytoluene

phosphorus pentoxide

phosphorus pentoxide

→

2,5-Difluoro-2′,6-dimethyl-4′,5′,6′-trimethoxybenzophenone

収率 67.0%

溶媒

water

dichloromethane

反応条件

後処理

1. 1
   workup.ADDITIONwere then added
2. 2
   workup.WAITAfter a further four hours
3. 3
   抽出extracted with dichloromethane
4. 4
   その他The combined organic phases were then dried
5. 5
   濃縮concentrated
6. 6
   その他The crude product was purified by reversed-phase MPLC (eluent acetonitrile/water 7:3)

実験手順

9.3 g (54.3 mmol) of 3,6-difluoro-2-methylbenzoic acid and 9.88 g (54.3 mmol) of 3,4,5-trimethoxytoluene were introduced into 250 ml of absolute dichloromethane, and 54 g (380 mmol) of pulverulent phosphorus pentoxide were then added. The mixture was stirred for 16 hours at room temperature. According to HPLC check, the trimethoxytoluene had not been reacted completely. A further 13.5 g of phosphorus pentoxide were added. After a further four hours, the reaction mixture was poured into water and extracted with dichloromethane. The combined organic phases were then dried and concentrated. The crude product was purified by reversed-phase MPLC (eluent acetonitrile/water 7:3). This gave 12.2 g of the compound I.5-02 (36 mmol, 67% yield).

出典