Methyl iodide → Lithium diisopropylamide

HRID 2380043Notes

Reaction equation

HRID 2380043 reaction equation
[CH:1]([NH:4][CH:5]([CH3:7])[CH3:6])([CH3:3])[CH3:2].[CH2:8]([Li:12])[CH2:9][CH2:10][CH3:11].CC1C=[CH:18][N:17]=[N:16][CH:15]=1.IC>CCCCCC.O1CCCC1.O>[CH:1]([N-:4][CH:5]([CH3:7])[CH3:6])([CH3:3])[CH3:2].[Li+:12].[CH2:10]([C:9]1[CH:8]=[CH:18][N:17]=[N:16][CH:15]=1)[CH3:11]

Participants

9

Reactant 4

HCID 6328Methyl iodideHCID 7912DiisopropylamineHCID 1368824-MethylpyridazineHCID 178418339Butyllithium

Product 2

HCID 2724682Lithium diisopropylamideHCID 18956526HCID 18956526, compound

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Procedure

A solution of lithium diisopropylamide was prepared as described in Example 1(i) from diisopropylamine (17.9 g) and n-butyllithium (70.4 ml of a 2.5M solution in hexane) in dry tetrahydrofuran (300 ml) under an atmosphere of dry nitrogen. To this solution at -70° was added 4-methylpyridazine, dropwise with stirring, ensuring that the temperature did not rise above -60°. Iodomethane (27.25 g) was added slowly with stirring, the solution was stirred at -70° for 1 hour and then allowed to warm to room temperature. Water was added and the solution was evaporated to low bulk. The solution was extracted three times with dichloromethane and the combined extracts were dried (Na2SO4) and evaporated. The residue was chromatographed on silica gel using ethyl acetate as eluant. The product fractions were combined and evaporated, and the residual oil was distilled to give the title compound, (10.4 g), b.p. 65°-66° at 0.1 mm.

Workup

  1. customdid not rise above -60°
  2. stirringwith stirring
  3. stirringthe solution was stirred at -70° for 1 hour
  4. customthe solution was evaporated to low bulk
  5. extractionThe solution was extracted three times with dichloromethane
  6. dry with materialthe combined extracts were dried (Na2SO4)
  7. customevaporated
  8. customThe residue was chromatographed on silica gel
  9. customevaporated
  10. distillationthe residual oil was distilled

Sources & evidence

ORD record
ord-b051b75345704e72b370044bd2295964
Source dataset
uspto-grants-1994_11
Patent number
US05364938

Reaction notes

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