Hydrazine, ethyl-, ethanedioate (1:1) → 4-(4-(2-Phenyleth-1-yl)-1-ethyl-(1h)-pyrazol-5-yl)-1-benzylpiperidine

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Reaction Steps

di-TFA salt A solution of 1-(1-benzylpiperidin-4-yl)-2-formyl-4-phenyl-1-butanone from Step E (76.5 mg) and ethylhydrazine oxalate (45 mg) in methanol (4 mL) was heated at 45° C. for 15.5 h. The solvent was removed under reduced pressure. The residue was purified by preparative reverse-phase IHPLC using a 9.4×250 mm Semi-preparative Zorbax SB-C18 column with 30-50% acetonitrile gradient in water having 0.5% (v/v) TFA over 15 min at 7.1 mL per min to give the title compound (45 mg) as the faster-eluting, minor isomer.

Provenance & Evidence