1837-55-4

Yellow solid powder.

3,5-Dichloropyridazine used in the treatment of asthma and allergy. Potential for antinociceptive and antiinflammatory effects

3,5-Dichloropyridazine can be used as a pharmaceutical reaction intermediate, for example, in the preparation of the compound 3-chloro-5-aminopyridazine. These compounds are commonly used chemical synthesis intermediates and have been widely applied in the research and development of drugs and pesticides in recent years, such as anticancer drugs (US2004/54186) and plant growth regulators (US1988/4728355).

ChEBI: 3,5-Dichloropyridazine is a member of pyridazines.

Preparation of 3,5-Dichloropyridazine:
2,4,4,4-Tetrachlorocrotonaldehyde is dissolved in a solvent, and a mixture of semicarbazide hydrochloride, water, and solvent is added dropwise under controlled temperature conditions. The reaction is stirred for 5 hours. Afterward, the reaction mixture is concentrated under reduced pressure to remove the solvent. Water is added, and the temperature is lowered to 5°C, allowing a solid to precipitate. The solid is filtered and recrystallized using a dichloromethane/petroleum ether mixture, yielding 3,5-dichloropyridazine as a white crystalline solid.