Isoprene → 2-Methylbuta-1,3-diene;styrene

HRID 369436Notes

Reaction equation

HRID 369436 reaction equation
[CH2:1]=[CH:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1.C([Li])CCC.C=CC(=C)C>C1CCCCC1.O1CCCC1>[CH2:1]=[CH:2][C:3](=[CH2:4])[CH3:8].[CH2:1]=[CH:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1

Participants

6

Reactant 3

HCID 6557Isoprene2×HCID 7501Styrene2×HCID 178418339Butyllithium

Product 1

HCID 1599892-Methylbuta-1,3-diene;styrene

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8078CyclohexaneSolvent

Conditions

Temperature
85 °C

Procedure

In a solution of styrene (41 g) in cyclohexane (1100 g), 0.3 ml of tetrahydrofuran and 1.2 g of 15 wt % n-butyllithium solution were added to initiate polymerization. The reaction was continued for 30 minutes, and the temperature was increased from 40° C. to 50° C. After most of the styrene monomer was reacted, 123 g of isoprene solution was added into the polymer mixture. The reaction was continued for an additional 90 minutes, and the temperature was increased from 55° C. to 80-90° C. After all of the isoprene monomer was completely reacted, a living styrene-isoprene block copolymer was formed in the first step.

Workup

  1. custompolymerization
  2. temperaturethe temperature was increased from 40° C. to 50° C
  3. waitThe reaction was continued for an additional 90 minutes

Sources & evidence

ORD record
ord-b27779508719469bb00cc8a634ca21ab
Source dataset
uspto-grants-2000_10
Patent number
US06136921

Reaction notes

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