Trifluoroacetic acid → 6-fluoro-3-(2-nitroethenyl)-1H-indole

HRID 1666843Notes

Reaction equation

HRID 1666843 reaction equation
[F:1][C:2]1[CH:10]=[C:9]2[C:5]([CH:6]=[CH:7][NH:8]2)=[CH:4][CH:3]=1.FC(F)(F)C(O)=O.CN(C)/[CH:20]=[CH:21]\[N+:22]([O-:24])=[O:23]>ClCCl>[N+:22]([CH:21]=[CH:20][C:6]1[C:5]2[C:9](=[CH:10][C:2]([F:1])=[CH:3][CH:4]=2)[NH:8][CH:7]=1)([O-:24])=[O:23]

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 3512786-FluoroindoleHCID 1714183HCID 1714183, compound

Product 1

HCID 673430236-fluoro-3-(2-nitroethenyl)-1H-indole

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
2.5 °C

Procedure

Combine 6-fluoroindole (108 g, 0.8 mol) and dichloromethane (324 ml). Cool in an ice bath. Add trifluoroacetic acid (308 ml) over a few minutes (exothermic). Add a solution of Z-1-dimethylamino-2-nitroethylene (94.7 g, 0.816 mol) in dichloromethane (600 ml) during 40 minutes while maintaining the temperature at about 0-5° C. After 45 minutes, warm to about 20° C. After 2 hours, pour over 1.2 L ice water and stirring overnight with seeding to give a solid. Collect the solid by filtration, wash first with 100 ml of a mixture dichloromethane-cyclohexane 1/1, then with 750 ml of water and dry at 4° C. to give 3-(2-nitrovinyl)-6-fluoroindole.

Workup

  1. temperatureCool in an ice bath
  2. temperaturewarm to about 20° C
  3. waitAfter 2 hours
  4. customto give a solid
  5. customCollect the solid
  6. filtrationby filtration
  7. washwash first with 100 ml of a mixture dichloromethane-cyclohexane 1/1
  8. dry with materialwith 750 ml of water and dry at 4° C.

Sources & evidence

ORD record
ord-e8d670ad77544bce81790fea3012e9e0
Source dataset
uspto-grants-2011_10
Patent number
US08044090B2

Reaction notes

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