反応 #62567

反応方程式

NH4Cl

2-Bromofluorobenzene

furan

dioxolanyl furan

magnesium

→

1-(1,3-dioxolan-2-yl)-1,4-epoxy-1,4-dihydronaphthalene

収率 77.1%

溶媒

THF

THF

反応条件

後処理

1. 1
   workup.ADDITIONAfter the addition
2. 2
   温度refluxing
3. 3
   その他the organic layer separated
4. 4
   抽出the aqueous layer re-extracted with ether
5. 5
   抽出The combined organic extract
6. 6
   洗浄was washed with saturated NH4Cl solution
7. 7
   乾燥dried over anhydrous K2CO3 -Na2SO4
8. 8
   濃縮concentrated in vacuo
9. 9
   その他The residue was purified on the Waters Prep 500 HPLC
10. 10
    洗浄eluting with EtOAc/hexane (1:4)

実験手順

2-Bromofluorobenzene (36.0 g, 0.222M) in THF (200 ml) was added dropwise over one hour to a refluxing mixture of the above furan (28.0 g, 0.200M) and magnesium turnings (5.4 g, 0.206M) in dry THF (200 ml) under nitrogen. After the addition was complete, refluxing was continued for one hour. The cooled mixture was then poured onto saturated NH4Cl solution (250 ml), the organic layer separated and the aqueous layer re-extracted with ether. The combined organic extract was washed with saturated NH4Cl solution, dried over anhydrous K2CO3 -Na2SO4 and concentrated in vacuo. The residue was purified on the Waters Prep 500 HPLC using two columns and eluting with EtOAc/hexane (1:4). A total of 33.3 g of 1-(1,3-dioxolan-2-yl)-1,4-epoxy-1,4-dihydronaphthalene was obtained as a pale yellow oil. Crystallization of the oil from hexane gave 32.5 g (75% yield) as white crystals, mp 48°-49° C.

出典