Isoprene → Isoprene butadiene

HRID 1781954Notes

Reaction equation

HRID 1781954 reaction equation
[CH2:1]=[CH:2][C:3](=[CH2:5])[CH3:4].[Na].[CH2:7]([Li])[CH2:8][CH2:9][CH3:10].C=CC=C>C1CCCCC1.O1CCCC1.CCCCC>[CH2:1]=[CH:2][C:3](=[CH2:4])[CH3:5].[CH2:7]=[CH:8][CH:9]=[CH2:10]

Participants

8

Reactant 4

HCID 6557IsopreneHCID 78451,3-ButadieneHCID 5360545SodiumHCID 178418339Butyllithium2×

Product 1

HCID 168288Isoprene butadiene

Reagents, catalysts & solvents 3

HCID 8003PentaneSolventHCID 8028TetrahydrofuranSolventHCID 8078CyclohexaneSolvent

Procedure

Eleven hundred milliliters of purified pentane was introduced under a nitrogen atmosphere into a two quart glass-bowled pressure reactor. The reactor was equipped with an air driven stirrer, a pressure gauge, a thermometer well, a heat exchange coil, a top surface inlet valve, a dip tube feeder with a valve, a syringe injection port containing a Viton rubber gasket, and a blow-out disk (200 psi). Five milliliters of a 0.1M dipyridyl in cyclohexane solution was injected into the reactor along with 8.0 mL of anhydrous tetrahydrofuran. Isoprene (18.6 g, 27.3 mL, 0.344 mol), freshly distilled from sodium, was added via syringe to the reaction vessel. The solution was heated to 50° C. and titrated by slow addition of 1.6M n-butyllithium until an orangish color persisted. Then 4.2 mL (6.7 mmol) of n-butyllithium was added. After 4 hr, butadiene (114.7 g, 155 mL, 2.12 mol) was pressured into the same reactor. The solution temperature was maintained at 50°-51° C. for 3 hours. The remainder of the procedure was the same as that described in Example V.

Workup

  1. customThe reactor was equipped with an air
  2. additionwas added via syringe to the reaction vessel
  3. temperatureThe solution temperature was maintained at 50°-51° C. for 3 hours

Sources & evidence

ORD record
ord-a3eda3d721a549a6bcd88ad5e8f9a4a3
Source dataset
uspto-grants-1997_05
Patent number
US05633415

Reaction notes

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