1-Bromo-4-iodobenzene → Tributyltin iodide

HRID 1949618Notes

Reaction equation

HRID 1949618 reaction equation
[CH2:1]([Sn:4]([CH2:13][CH2:14][CH2:15][CH3:16])([CH2:9][CH2:10][CH2:11][CH3:12])[CH2:5][CH2:6][CH2:7][CH3:8])[CH:2]=[CH2:3].[Br:17][C:18]1[CH:23]=[CH:22][C:21]([I:24])=[CH:20][CH:19]=1>>[CH2:3]([C:21]1[CH:22]=[CH:23][C:18]([Br:17])=[CH:19][CH:20]=1)[CH:2]=[CH2:1].[CH2:5]([Sn:4]([I:24])([CH2:13][CH2:14][CH2:15][CH3:16])[CH2:9][CH2:10][CH2:11][CH3:12])[CH2:6][CH2:7][CH3:8]

Participants

4

Reactant 2

HCID 115221-Bromo-4-iodobenzeneHCID 90628Allyltributylstannane

Product 2

HCID 23765Tributyltin iodideHCID 137529Benzene, 1-bromo-4-(2-propenyl)-

Procedure

In a Stille coupling reaction, 1-bromo-4-iodobenzene and allyltri-n-butyltin were reacted to yield Compound 1. Thus, tetrakistriphenylphosphine palladium(0) (1.976 g, 1.710×10−3 mol) was weighed out in a nitrogen-filled glove box and transferred to a Schlenk line. Allyltri-n-butyltin (10.60 mL, 3.419×10−2 mol) and 1-bromo-4-iodobenzene (9.680 g, 3.422×10−2 mol) were added along with 115 mL distilled, degassed 1,4-dioxane to yield a yellow reaction mixture that darkened to orange as the reaction progressed. The reaction mixture was stirred at 70° C. for 46 h until analysis by TLC (hexanes) and GC/MS showed that reaction was complete. The mixture was next cooled to room temperature, filtered through Celite (rinsing with hexanes), and resulting solution washed with both hexanes and water, to remove PPh3. Then the organic portion was dried over MgSO4. Filtration through Celite and removal of the solvent in a rotary evaporator at <75° C. yielded an orange oil. Column chromatography on silica gel with hexanes as eluant afforded only Compound 1 and tri-n-butyltin iodide. These were separated via vacuum distillation at 160 mTorr, where Compound 1 distills at about 50° C. (never exceed 75° C., which can potentially cause allyl group isomerization) as a clear colorless oil (2.810 g, 42% yield). GC/MS: single peak; m/z (rel. intensity) 198 (M+, 46), 196 (M+, 46), 117 (100), 115 (86). 1H NMR (CDCl3): δ7.41 (d, J=8.5 Hz, 2H), 7.07 (d, J=8.0 Hz, 2H), 5.90 (m, 1H), 5.09 (m, 2H), 3.36 (d, J=7.0 Hz, 2H).

Workup

  1. additionfilled glove box
  2. customtransferred to a Schlenk
  3. distillationdistilled
  4. customdegassed 1,4-dioxane
  5. customto yield a yellow reaction mixture that darkened to orange as the reaction
  6. customshowed that reaction
  7. filtrationfiltered through Celite (rinsing with hexanes)
  8. customresulting solution
  9. washwashed with both hexanes and water
  10. customto remove PPh3
  11. dry with materialThen the organic portion was dried over MgSO4
  12. filtrationFiltration
  13. customthrough Celite and removal of the solvent
  14. customin a rotary evaporator at <75° C.
  15. customyielded an orange oil

Sources & evidence

ORD record
ord-a27518fe1bc3493fa9ac000854466a19
Source dataset
uspto-grants-2013_03
Patent number
US08399761B2

Reaction notes

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