Iodine → 3-(4-Methylpent-3-enyl)thiophene

HRID 1614140Notes

Reaction equation

HRID 1614140 reaction equation
Br[CH2:2][C:3]1[CH:7]=[CH:6][S:5][CH:4]=1.[CH2:8](Cl)[CH:9]=[C:10]([CH3:12])[CH3:11].[Mg].II.BrCC1SC=CC=1.[Cl-].[NH4+]>[Cu]I.O.O1CCCC1>[CH3:11][C:10]([CH3:12])=[CH:9][CH2:8][CH2:2][C:3]1[CH:7]=[CH:6][S:5][CH:4]=1

Participants

10

Reactant 6

HCID 807IodineHCID 104291-Chloro-3-methyl-2-butene2×HCID 25517Ammonium ChlorideHCID 5207033-(Bromomethyl)thiopheneHCID 5462224Magnesium4×HCID 118299782-(Bromomethyl)thiophene

Product 1

HCID 5661073-(4-Methylpent-3-enyl)thiophene

Reagents, catalysts & solvents 3

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
40 °C

Procedure

217 g of 3-bromomethylthiophene, 513 g of prenylchloride, 117 g of copper (I) iodide and 2 kg of tetrahydrofuran were introduced into a 4-liter reaction flask. 750 g of magnesium shavings were then added in small portions at a rate such that the temperature of the reaction mixture did not rise above 30°. If the temperature rises were to great, the reaction mixture was temporarily cooled. The first portion of magnesium was activated by subliming an iodine crystal onto it. After all the magnesium had been added, a check was made by means of GLC as to whether bromomethylthiophene or prenyl chloride was still present. It was possibly necessary to add more magnesium. The mixture was then stirred for a further hour at 40° C. and after that poured out into a mixture of 180 g of ammonium chloride, 1 liter of water and 500 g of ice, and stirred.

Workup

  1. customdid not rise above 30°
  2. temperaturewas temporarily cooled
  3. stirringstirred

Sources & evidence

ORD record
ord-1672b4b70d2d4158926317481463db38
Source dataset
uspto-grants-1993_03
Patent number
US05196224

Reaction notes

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