Carbon tetrabromide → 1-(2,2-Dibromoethenyl)-3-fluorobenzene

To a stirred, cooled (ice/salt, 0°) solution of carbon tetrabromide (48.82 g) in anhydrous DCM (200 ml) was added, portionwise over 3 minutes, triphenylphosphine (77.1 g), maintaining the temperature below 10°. The resulting orange suspension was stirred at 0° for 1 hour before adding to it 3-fluorobenzaldehyde (7.8 ml). After the addition was complete, the suspension was stirred at 0° for 1 hour then quenched by the addition of water (75 ml). The organic phase was separated and washed with brine (75 ml), dried (Na2SO4) and evaporated to dryness. The residue was poured into cyclohexane (1 L) and stirred for 30 minutes. The organic phase was decanted and the residue taken up into DCM and poured into cyclohexane (1 L). This procedure was repeated twice more and the combined organic phases concentrated to ˜100 ml and passed through silica gel. The filtrate was concentrated to give the title compound as a mobile yellow oil (24 g, 100%). MH+ 280, MH− 279

1. additionwas added, portionwise over 3 minutes
2. additionAfter the addition
3. stirringthe suspension was stirred at 0° for 1 hour
4. customthen quenched by the addition of water (75 ml)
5. customThe organic phase was separated
6. washwashed with brine (75 ml)
7. dry with materialdried (Na2SO4)
8. customevaporated to dryness
9. additionThe residue was poured into cyclohexane (1 L)
10. stirringstirred for 30 minutes
11. customThe organic phase was decanted
12. additionpoured into cyclohexane (1 L)
13. concentrationthe combined organic phases concentrated to ˜100 ml
14. concentrationThe filtrate was concentrated

ORD record

ord-0eed646aa2b24c498323d8f86c05b0d0

Source dataset

uspto-grants-2007_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07223772B1