Dimethylformamide → Phenobarbital

HRID 1658942Notes

Reaction equation

HRID 1658942 reaction equation
[CH3:1][CH2:2][C:3]1([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[C:9](=[O:10])[N:8]=[C:7]([O-:11])[NH:6][C:4]1=[O:5].[Na+].ClCC([O-])=O.[Na+].[Cl-].[Cl-].[Ca+2].CN(C=O)C>CO>[CH3:1][CH2:2][C:3]1([C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=2)[C:9](=[O:10])[NH:8][C:7](=[O:11])[NH:6][C:4]1=[O:5]

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 5284359Calcium ChlorideHCID 23665759Sodium chloroacetateHCID 23674889Phenobarbital sodium

Product 1

HCID 4763PhenobarbitalYield 36.9%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

A solution of sodium phenobarbitone (8.8 g, 35 mmoles), and sodium chloroacetate (4.5 g, 38 mmoles) in methanol (250 ml) was mixed with a solution of CaCl2 (3 g) in methanol (50 ml). After addition of 5 ml DMF the mixture was refluxed for 36 hours. After removal of the solvent, the residue was treated with water (100 ml) and acidified with conc. HCl followed by extraction with chloroform. The organic layer was evaporated to dryness and the residue treated with 10% NaHCO3 solution. Extraction with chloroform and evaporation of the organic layer yielded 3 g of unreacted phenobarbital. The bicarbonate layer was acidified with conc. HCl and extracted with chloroform. Evaporation of the dried (MgSO4) chloroform yielded 4.5 g of a gummy material which solidified slowly on standing. TLC and NMR showed this to be nearly pure monoacid with only traces of unreacted phenobarbitone and dialkylated derivative.

Workup

  1. temperaturewas refluxed for 36 hours
  2. customAfter removal of the solvent
  3. additionthe residue was treated with water (100 ml)
  4. extractionfollowed by extraction with chloroform
  5. customThe organic layer was evaporated to dryness
  6. additionthe residue treated with 10% NaHCO3 solution
  7. extractionExtraction
  8. customwith chloroform and evaporation of the organic layer

Sources & evidence

ORD record
ord-7bd69fe7ae104c648bd5d7ea79d4eeb8
Source dataset
uspto-grants-1976_06
Patent number
US03966764

Reaction notes

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