N-[3-[3-(Dimethylamino)-1-oxo-2-propenyl]-phenyl]-N-methylacetamide → Zaleplon Impurity 16

HRID 231504Notes

Reaction equation

HRID 231504 reaction equation
[NH2:1][C:2]1[C:6]([C:7]#[N:8])=[CH:5][NH:4][N:3]=1.CN(C)[CH:11]=[CH:12][C:13]([C:15]1[CH:16]=[C:17]([N:21]([CH3:25])[C:22](=[O:24])[CH3:23])[CH:18]=[CH:19][CH:20]=1)=O>C(O)(=O)C>[C:7]([C:6]1[CH:5]=[N:4][N:3]2[C:13]([C:15]3[CH:16]=[C:17]([N:21]([CH3:25])[C:22](=[O:24])[CH3:23])[CH:18]=[CH:19][CH:20]=3)=[CH:12][CH:11]=[N:1][C:2]=12)#[N:8]

Participants

4

Reactant 2

HCID 53424451N-[3-[3-(Dimethylamino)-1-oxo-2-propenyl]-phenyl]-N-methylacetamideHCID 178510443HCID 178510443, compound

Product 1

HCID 11779028Zaleplon Impurity 16

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A mixture of 540 mg of 3-aminopyrazole-4-carbonitrile, 1.23 g of N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-methylacetamide and 50 ml of glacial acetic acid was heated at reflux for 8 hours then the solvent was removed: The residue was partitioned between saturated aqueous sodium bicarbonate and dichloromethane. The organic layer was separated, dried, passed through a pad of hydrous magnesium silicate and hexane was added to the refluxing filtrate to crystallize the product. The mixture was cooled and the solid collected, giving the desired product, mp 195°-197° C.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 8 hours
  3. customthe solvent was removed
  4. customThe residue was partitioned between saturated aqueous sodium bicarbonate and dichloromethane
  5. customThe organic layer was separated
  6. customdried
  7. additionwas added to the refluxing filtrate
  8. customto crystallize the product
  9. temperatureThe mixture was cooled
  10. customthe solid collected

Sources & evidence

ORD record
ord-14d7cf7143e74defa2beecc768917738
Source dataset
uspto-grants-1989_07
Patent number
US04847256

Reaction notes

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