Hydrochloric Acid → 2-chloro-5H-thiazolo[4,5-d]pyridazin-4-one

Participants

Reaction Steps

The compound (688 mg) obtained in Step 4 was suspended in 6N aqueous hydrochloric acid solution (10 ml), and sodium nitrite (1.41 g) was added in several portions with stirring at room temperature, and the mixture was further stirred at room temperature for 1 hr. Water was added, with stirring at room temperature, and the solid was collected by filtration, washed with water, and dried to give the title compound (571 mg).

Provenance & Evidence