Isoprene → HCID 19864713, compound

HRID 1464234Notes

Reaction equation

HRID 1464234 reaction equation
[CH2:1]=[CH:2][C:3](=[CH2:5])[CH3:4].[CH:6]([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][N:9]=1)=[CH2:7].C([Li])(CC)C>>[CH2:1]=[CH:2][C:3](=[CH2:4])[CH3:5].[CH:6]([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][N:9]=1)=[CH2:7]

Participants

4

Reactant 3

HCID 6557Isoprene2×HCID 75212-Vinylpyridine3×HCID 178418400CID 536281002×

Product 1

HCID 19864713HCID 19864713, compound

Conditions

Temperature
40 °C

Procedure

The diblock copolymer was prepared by a sequential addition of isoprene and and 2-vinylpyridine to secbutyllithium. Benzene (500 ml) was degassed as before with oxygen-free argon for 45 minutes. Secbutyllithium (0.8 ml of 1.3M, 1.04 mmoles) was syringed in followed by 63.13 g (0.93 moles) of isoprene. The solution was stirred at 35° C. for 15 minutes and 40° C. for 15 minutes. There was an exotherm to 45° C. The solution was stirred at 45° C. for 11/2 hours more. As before the magnetic stirring system was switched to a mechanical for more efficient stirring. An aliquot of polyisoprene was syringed out for determination of the molecular weight of the starting block and the solution cooled to 8° C. At this stage 2-vinylpyridine (27.06 g, 0.26 mole) was added. Chain transfer to 2-vinylpyridine was noticed by the dark red color. The solution was stirred at 8° C. for 30 minutes and was quenched with degassed methanol. As before, the copolymer was characterized by 1H NMR and GPC. These results are also summarized in Table 1.

Workup

  1. customBenzene (500 ml) was degassed as before with oxygen-free argon for 45 minutes
  2. customto 45° C
  3. stirringThe solution was stirred at 45° C. for 11/2 hours more
  4. temperaturethe solution cooled to 8° C
  5. stirringThe solution was stirred at 8° C. for 30 minutes
  6. customwas quenched with degassed methanol

Sources & evidence

ORD record
ord-e6daa812cf0349a4b409d6d140049ac6
Source dataset
uspto-grants-1994_04
Patent number
US05304458

Reaction notes

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