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

Participants

Reaction Steps

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).

Provenance & Evidence