Benzyl Bromide → 5-(3,4-Dimethoxyphenyl)-2-benzylpyrazolin-3-one

HRID 1078354Notes

Reaction equation

HRID 1078354 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:11]2[NH:15][NH:14][C:13](=[O:16])[CH2:12]2)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].N1[C:22]([CH3:23])=[CH:21][C:20](C)=[CH:19][C:18]=1[CH3:25].C(Br)C1C=CC=CC=1>C1(C)C=CC=CC=1.ClCCl>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:11]2[NH:15][N:14]([CH2:25][C:18]3[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=3)[C:13](=[O:16])[CH2:12]2)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10]

Participants

6

Reactant 3

HCID 7498Benzyl BromideHCID 79532,4,6-TrimethylpyridineHCID 220460885-(3,4-Dimethoxyphenyl)-pyrazolin-3-one

Product 1

HCID 229023385-(3,4-Dimethoxyphenyl)-2-benzylpyrazolin-3-one

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 6344DichloromethaneSolvent

Procedure

5 g of 5-(3,4-dimethoxyphenyl)-pyrazolin-3-one, prepared according to Example 1C, were suspended in 100 ml of toluene. First 3 ml of collidine and subsequently 3.6 ml of benzyl bromide were added dropwise to the suspension. After heating for 6 hours under reflux, the reaction mixture was cooled, and the precipitated crystals were filtered out and washed with isopropanol. The crystals obtained were dissolved in dichloromethane and washed with 2M citric acid. The organic phase was dried with magnesium sulfate and concentrated. For purification the residue was recrystallized from isopropanol. 4 g of 5-(3,4-dimethoxyphenyl)-2-benzyl-pyrazolin-3-one were obtained having a melting point of 165° C.

Workup

  1. temperatureAfter heating for 6 hours
  2. temperatureunder reflux
  3. temperaturethe reaction mixture was cooled
  4. filtrationthe precipitated crystals were filtered out
  5. washwashed with isopropanol
  6. customThe crystals obtained
  7. washwashed with 2M citric acid
  8. dry with materialThe organic phase was dried with magnesium sulfate
  9. concentrationconcentrated
  10. customFor purification the residue
  11. customwas recrystallized from isopropanol

Sources & evidence

ORD record
ord-eb40e8b17603436787bcc9fe9812463a
Source dataset
uspto-grants-1996_08
Patent number
US05547967

Reaction notes

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