1,2-Dibromoethane → 2-(2-Bromoethyl)-4-methylphthalazin-1(2H)-one

HRID 981021Notes

Reaction equation

HRID 981021 reaction equation
[CH3:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5](=[O:12])[NH:4][N:3]=1.[H-].[Na+].[H][H].[Br:17][CH2:18][CH2:19]Br>CN(C)C=O>[CH3:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5](=[O:12])[N:4]([CH2:19][CH2:18][Br:17])[N:3]=1

Participants

6

Reactant 4

HCID 78391,2-DibromoethaneHCID 211031-Hydroxy-4-methylphthalazineHCID 24758Sodium hydrideHCID 178418361HCID 178418361, compound

Product 1

HCID 217614862-(2-Bromoethyl)-4-methylphthalazin-1(2H)-one

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

4-Methyl-(2H)-phthalazin-1-one (6 g) and sodium hydride (1.5 g, 60% in oil) in dimethylformamide (DMF) were stirred at room temperature until hydrogen evolution ceased. To this suspension was added a five fold excess of 1,2-dibromoethane (25 ml) and stirring was continued for a further 2 hours. The solvent was removed and the residue taken up in ethyl acetate, washed twice with brine, dried (MgSO4) and evaporated. Chromatography on silica [Merck `Kieselgel 60` (Trade Mark)] eluting with methylene chloride containing methanol (0% up to 5%) gave, after collection and evaporation of appropriate fractions, a solid which was recrystallised from ethanol to give the title compound, yield 6.25 g, m.p. 102°-103°, used in the next stage.

Workup

  1. customThe solvent was removed
  2. washwashed twice with brine
  3. dry with materialdried (MgSO4)
  4. customevaporated
  5. washChromatography on silica [Merck `Kieselgel 60` (Trade Mark)] eluting with methylene chloride
  6. additioncontaining methanol (0% up to 5%)
  7. customgave
  8. customafter collection and evaporation of appropriate fractions
  9. customa solid which was recrystallised from ethanol

Sources & evidence

ORD record
ord-ba5124323215466cb14e05f56d0adeaf
Source dataset
uspto-grants-1991_02
Patent number
US04990509

Reaction notes

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