(4-Chlorophenyl)hydrazine → [2-(4-Chloro-phenyl)-2,4,5,6-tetrahydro-cyclopentapyrazol-3-yl]-cyclohexyl-acetic acid ethyl ester

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Reaction Steps

(4-Chloro-phenyl)-hydrazine (5.63 g, 31 mmol; CAS Reg. No. 1073-69-4) was added to a solution of 2-cyclohexyl-3-oxo-3-(2-oxo-cyclopentyl)-propionic acid ethyl ester (8.8 g, 31 mmol) in ethanol (200 ml). The reaction mixture was heated under reflux conditions for 6 h. The solvent was removed under reduced pressure. The residue was suspended in dichloromethane and filtered off. The filtrate was brought to dryness under reduced pressure to give a brown oil which was purified by column chromatography (silica gel, iPrOAc/heptane) to give the title compound (6.26 g, 16 mmol; 51%) as orange oil. MS: m/e=388.4 [M+H+].

Provenance & Evidence