Regioselective synthesis of 1,5-diarylpyrazole anti-inflammatory agents

摘要

The invention provides a process for preparing 1,5-diaryl pyrazole anti-inflammatory agents. A 6-aryl-4,6-dioxohexanoic acid is treated with acetic anhydride or acetyl chloride to produce an enol lactone, which is added to methylhydroxylamine to generate the dione hydroxamic acid. This dione hydroxamic acid is then treated with 4-methoxyphenylhydrazine hydrochloride to yield the 1,5-diaryl pyrazole. Novel intermediate compounds in the synthetic pathway are also disclosed.