Ammonia → 2,3-Dihydro4-methyl-2-oxo-1-pyrid-3-ylmethyleneamino-1H-imidazole

HRID 1489508Notes

Reaction equation

HRID 1489508 reaction equation
[C:1]([CH2:4][N:5]1[N:9]=[C:8]([CH3:10])O[C:6]1=[O:11])(=O)[CH3:2].[NH3:12]>C(#N)C>[CH3:2][C:1]1[NH:12][C:6](=[O:11])[N:5]([N:9]=[CH:8][C:10]2[CH:6]=[N:5][CH:4]=[CH:1][CH:2]=2)[CH:4]=1

Participants

4

Reactant 2

HCID 222AmmoniaHCID 110409205-Methyl-3-(2-oxopropyl)-1,3,4-oxadiazol-2(3H)-one

Product 1

HCID 541240302,3-Dihydro4-methyl-2-oxo-1-pyrid-3-ylmethyleneamino-1H-imidazole

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A solution of 156 g of 3-acetylmethyl-2,3-dihydro-5-methyl-2-oxo-1,3,4-oxadiazole in 600 ml of acetonitrile is treated with 170 g of aqueous ammonia solution (30%), and the mixture is stirred for one hour at 80° in an autoclave. A pressure of approximately 8 bar is in this case established. The resulting suspension is evaporated, the residue is dissolved in 500 ml of methanol, and 40 g of gaseous HCl are passed into the solution at 50°. The reaction mixture is stirred for 30 minutes at 50°, and 107 g of 3-formylpyridine are then added dropwise at the same temperature. The reaction mixture is stirred for a further 30 minutes at 50°, then cooled to 0°, and filtered with suction. The filter cake, consisting of 2,3-dihydro-2-oxo-1-pyrid-3-ylmethyleneamino-4-tert-butyl-1H-imidazole hydrochloride (compound no. 4.1.1 in table 4), is dissolved in water at room temperature. The pH of the solution is brought to approximately 7 using aqueous sodium hydroxide solution (30%), during which process a precipitation of crystals is observed at a pH of approximately 3. The crystals are filtered off with suction and dried in vacuo, yielding the title compound melting at 200°-202°.

Workup

  1. customThe resulting suspension is evaporated
  2. dissolutionthe residue is dissolved in 500 ml of methanol
  3. customare passed into the solution at 50°
  4. stirringThe reaction mixture is stirred for 30 minutes at 50°
  5. addition107 g of 3-formylpyridine are then added dropwise at the same temperature
  6. stirringThe reaction mixture is stirred for a further 30 minutes at 50°
  7. temperaturecooled to 0°
  8. filtrationfiltered with suction
  9. dissolutionis dissolved in water at room temperature
  10. customa precipitation of crystals
  11. filtrationThe crystals are filtered off with suction
  12. customdried in vacuo

Sources & evidence

ORD record
ord-ddfbe81354c042fcab3883590ce465d4
Source dataset
uspto-grants-1997_10
Patent number
US05679623

Reaction notes

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