Ammonia → 4-amino-3-ethyl-1H-1,2,4-triazol-5-one

HRID 465679Notes

Reaction equation

HRID 465679 reaction equation
[OH2:1].[NH2:2][NH2:3].[C:4](=[O:19])(OC1C=CC=CC=1)OC1C=CC=CC=1.[C:20](#[N:23])[CH2:21][CH3:22].[NH3:24]>C1(O)C=CC=CC=1.C[Sn](=O)C>[C:20]([NH:23][NH2:24])([NH:2][NH2:3])=[O:1].[CH2:21]([C:20]1[N:2]([NH2:3])[C:4](=[O:19])[NH:24][N:23]=1)[CH3:22]

Participants

8

Reactant 4

HCID 222AmmoniaHCID 7597Diphenyl carbonateHCID 7854PropionitrileHCID 24654Hydrazine hydrate (1:1)

Product 2

HCID 73948CarbohydrazideHCID 3844914-amino-3-ethyl-1H-1,2,4-triazol-5-oneYield 85%

Reagents, catalysts & solvents 2

HCID 75277DimethyloxostannaneCatalystHCID 996PhenolSolvent

Conditions

Temperature
125 °C

Procedure

Analogously to Example 3, a solution of carbodihydrazide in phenol is prepared from 3,200 g (64 mol) of hydrazine hydrate and 6,848 g (32 mol) of diphenyl carbonate and the water of hydration and also 1,500 ml of phenol are then distilled off. After addition of 3 g of dimethyltin oxide and 1,848 g (33.6 mol) of propionitrile, the mixture is heated to a weak reflux (125° C.). The temperature can be increased to 180° C. in the course of 11 hours under a continuous reflux. Thereafter, the evolution of NH3 has ended. Phenol is now distilled off at a bottom temperature of 160° C. under reduced pressure (decreasing to 15 mbar), the residue remaining liquid. Residual phenol is therefore removed under 1 mbar using an oil pump. After cooling, the residue is dissolved in 3 1 of hot water. 80 ml of diethylamine and 10 g of tartaric acid (to remove a slight turbidity caused by the catalyst) are added to the solution. A diethylamine excess and traces of phenol are removed by incipient distillation. After cooling to 10° C., the product is filtered off with suction, washed with 500 ml of cold 50% strength ethanol and dried at 100° C. in vacuo. 3,478 g (85% of theory) of 3-ethyl-4-amino-1,2,4-triazol-5-one of melting point 171° C. are obtained.

Workup

  1. distillationthe water of hydration and also 1,500 ml of phenol are then distilled off
  2. temperaturethe mixture is heated to
  3. temperatureThe temperature can be increased to 180° C. in the course of 11 hours under a continuous reflux
  4. distillationPhenol is now distilled off at a bottom temperature of 160° C. under reduced pressure (decreasing to 15 mbar)
  5. customResidual phenol is therefore removed under 1 mbar
  6. temperatureAfter cooling
  7. dissolutionthe residue is dissolved in 3 1 of hot water
  8. custom80 ml of diethylamine and 10 g of tartaric acid (to remove a slight turbidity
  9. additionare added to the solution
  10. customare removed by incipient distillation
  11. temperatureAfter cooling to 10° C.
  12. filtrationthe product is filtered off with suction
  13. washwashed with 500 ml of cold 50% strength ethanol
  14. customdried at 100° C. in vacuo

Sources & evidence

ORD record
ord-b2e1984812524a79851cb0014691d55f
Source dataset
uspto-grants-1992_10
Patent number
US05153326

Reaction notes

Loading…