Sodium Azide → HCID 13341556, compound

HRID 1981123Notes

Reaction equation

HRID 1981123 reaction equation
Br[CH:2]1[CH2:14][N:5]2[CH2:6][CH2:7][CH2:8][CH:9]([C:10]([O:12][CH3:13])=[O:11])[N:4]2[C:3]1=[O:15].[N-:16]=[N+:17]=[N-:18].[Na+]>CC(C)=O>[N:16]([CH:2]1[CH2:14][N:5]2[CH2:6][CH2:7][CH2:8][CH:9]([C:10]([O:12][CH3:13])=[O:11])[N:4]2[C:3]1=[O:15])=[N+:17]=[N-:18]

Participants

4

Reactant 2

HCID 33557Sodium AzideHCID 13341555HCID 13341555, compound

Product 1

HCID 13341556HCID 13341556, compoundYield 28%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

4.5 g of methyl 2-bromo-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate (2 racemates) and 1.58 g of sodium azide in 30 ml of acetone were stirred and heated under reflux for 48 hours. The mixture was evaporated and the residue was partitioned between dichloromethane and water. The organic phase was separated, dried over magnesium sulphate and evaporated. The residue was chromatographed on silica gel. Elution with diethyl ether/methanol (19:1, v/v) gave firstly 2.5 g (65%) of methyl 2-azido-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate (racemate A) in the form of a white solid of melting point 92°-93° C. (from ethyl acetate/n-hexane) and secondly 1.08 g (28%) of methyl 2-azido-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate (racemate B) in the form of a white solid of melting point 70°-71.5° C. (from diethyl ether/n-hexane).

Workup

  1. temperatureheated
  2. temperatureunder reflux for 48 hours
  3. customThe mixture was evaporated
  4. customthe residue was partitioned between dichloromethane and water
  5. customThe organic phase was separated
  6. dry with materialdried over magnesium sulphate
  7. customevaporated
  8. customThe residue was chromatographed on silica gel
  9. washElution with diethyl ether/methanol (19:1

Sources & evidence

ORD record
ord-80ac0332d3d6419386c8af5ee408a7da
Source dataset
uspto-grants-1985_04
Patent number
US04512924

Reaction notes

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