反应 #570467

反应方程式

1,2-dibromoethane

hydrochloric acid

2-bromobenzaldehyde

1,2-dibromoethane

1,2-dibromoethane

magnesium

4-iodobenzotrifluoride

→

oil

收率 136.3%

4'-Trifluoromethyl-2-biphenylcarbaldehyde

收率 136.3%

溶剂

THF

THF

THF

THF

tetrahydrofuran

反应条件

后处理

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   温度to maintain gentle reflux
3. 3
   温度The mixture was then refluxed an additional 20 minutes
4. 4
   其他decanted into an addition funnel
5. 5
   其他attached to a second reaction flask
6. 6
   温度the mixture refluxed for 11/2 hr
7. 7
   其他the THF evaporated on the rotary evaporator
8. 8
   萃取The residue was extracted with diethyl ether
9. 9
   萃取The ether extract
10. 10
    洗涤was washed with 3N hydrochloric acid (20 mL) water (4×25 mL), and saturated sodium chloride solution (10 mL)
11. 11
    干燥The ether solution was then dried (MgSO4)
12. 12
    workup.ADDITIONtreated with charcoal
13. 13
    过滤filtered
14. 14
    其他evaporated

实验过程

To magnesium turnings (1.23 g, 50.7 mmol) in a dry flask under nitrogen was added anhydrous tetrahydrofuran (THF, 10 mL). The mixture was mechanically stirred while a solution of 1,2-dibromoethane (1.22 g, 6.5 mmol) in THF (10 mL) was added dropwise. Upon completion, a solution of the dimethyl acetal of 2-bromobenzaldehyde (3.00 g, 13.0 mmol) and 1,2-dibromoethane (2.44 g, 13.0 mmol) in THF (10 ml) was added at a rate to maintain gentle reflux. Upon completing, a second solution of 1,2-dibromoethane (1.22 g, 6.5 mmol) in THF (10 mL) was added dropwise. The mixture was then refluxed an additional 20 minutes and decanted into an addition funnel attached to a second reaction flask containing a solution of 4-iodobenzotrifluoride (2.72 g, 10.0 mmol) and iodo(4-trifluoromethyl)bis(triphenylphosphine)palladium (II) (0.21 g, 0.9 mmol) in refluxing THF (20 mL). The Grignard reagent was added dropwise and the mixture refluxed for 11/2 hr. After cooling to room temperature, 3N hydrochloric acid was added (30 mL) and the THF evaporated on the rotary evaporator. The residue was extracted with diethyl ether. The ether extract was washed with 3N hydrochloric acid (20 mL) water (4×25 mL), and saturated sodium chloride solution (10 mL). The ether solution was then dried (MgSO4), treated with charcoal, filtered and evaporated to give a dark yellow oil (3.41 g). This was chromatographed on the Waters Prep 500 HPLC using a 1:1 mixture of methylene chloride and hexane. The product was isolated after evaporation of solvent as a light yellow oil (2.41 g, 96.4%). 'H NMR (CDCl3): 7.6 (m, 7, Ar--H), 8.0 (m, 1, 3-H), 9.9 (s, 1, CHO).

来源