반응 #570467

반응 방정식

1,2-dibromoethane

hydrochloric acid

2-bromobenzaldehyde

1,2-dibromoethane

1,2-dibromoethane

magnesium

4-iodobenzotrifluoride

→

oil

수율 136.3%

4'-Trifluoromethyl-2-biphenylcarbaldehyde

수율 136.3%

용매

THF

THF

THF

THF

tetrahydrofuran

반응 조건

후처리

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   온도to maintain gentle reflux
3. 3
   온도The mixture was then refluxed an additional 20 minutes
4. 4
   기타decanted into an addition funnel
5. 5
   기타attached to a second reaction flask
6. 6
   온도the mixture refluxed for 11/2 hr
7. 7
   기타the THF evaporated on the rotary evaporator
8. 8
   추출The residue was extracted with diethyl ether
9. 9
   추출The ether extract
10. 10
    세척was washed with 3N hydrochloric acid (20 mL) water (4×25 mL), and saturated sodium chloride solution (10 mL)
11. 11
    건조The ether solution was then dried (MgSO4)
12. 12
    workup.ADDITIONtreated with charcoal
13. 13
    여과filtered
14. 14
    기타evaporated

실험 절차

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).

출처