Ethyl 2-oxocyclohexanecarboxylate → (2-fluoro-4-chloro-5-cyclopentyloxyphenyl)-1,2,4,5,6,7-hexahydro-3H-indazol-3-one

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Reaction Steps

2-Fluoro-4-chloro-5-cyclopentyloxyphenylhydrazine (24.5 g, 0.10 mol), 2-ethoxycarbonylcyclohexanone (17.0 g, 0.10 mol) were dissolved in acetic acid (200 ml), and stirred for 2 hours while heating under refluxing. After completion of the reaction, the solvent was distilled off to obtain a crude product (37 g). The product was washed with a mixed solvent of benzene/hexane to obtain 2N-(2-fluoro-4-chloro-5-cyclopentyloxyphenyl)-1,2,4,5,6,7-hexahydro-3H-indazol-3-one as a white solid (25.3 g, 72.3% yield)

Provenance & Evidence