Acetic Acid → 2-amino-6H-thiazolo[4,5-d]pyridazin-7-one

HRID 908633Notes

Reaction equation

HRID 908633 reaction equation
C[O:2][C:3]([C:5]1[S:9][C:8]([NH2:10])=[N:7][C:6]=1[CH:11]=O)=O.O.[NH2:14][NH2:15].C(O)(=O)C>C(O)C>[NH2:10][C:8]1[S:9][C:5]2[C:3](=[O:2])[NH:15][N:14]=[CH:11][C:6]=2[N:7]=1

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 24654Hydrazine hydrate (1:1)HCID 597038082-Amino-4-formylthiazole-5-carboxylic acid methyl ester

Product 1

HCID 597037542-amino-6H-thiazolo[4,5-d]pyridazin-7-one

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of the compound (1.20 g) obtained in Step 4 in ethanol (120 ml) was added hydrazine monohydrate (374 μl), and the mixture was heated under reflux for 24 hr. Since the reaction was not completed, acetic acid (1.0 ml) was added, and the mixture was further heated under reflux for 20 hr. The reaction mixture was concentrated under reduced pressure to an amount of 5 ml, a small amount of ethanol was added, and the mixture was stirred at room temperature for 30 min. The precipitated solid was collected by filtration, washed with a small amount of ethanol, and dried to give the title compound (822 mg).

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 24 hr
  3. temperaturethe mixture was further heated
  4. temperatureunder reflux for 20 hr
  5. concentrationThe reaction mixture was concentrated under reduced pressure to an amount of 5 ml
  6. additiona small amount of ethanol was added
  7. filtrationThe precipitated solid was collected by filtration
  8. washwashed with a small amount of ethanol
  9. customdried

Sources & evidence

ORD record
ord-4450c9f7888f4af3921e57e1484907c9
Source dataset
uspto-grants-2011_09
Patent number
US08017612B2

Reaction notes

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