Hydrazine, ethyl-, ethanedioate (1:1) → 4-(5-benzyl-1-ethyl-(1H-pyrazol-3-yl))-1-t-butoxycarbonylpiperidine

Participants

Reaction Steps

1-(1-(t-Butoxycarbonyl)piperidin-4-yl)-4-phenylbutane-1,3-dione from Step A, from Method A or Method B, Step B3, (0.851 g, 2.46 mmol) in methanol (25 mL) was added over 10 min to a suspension of ethylhydrazine oxalate (0.444 g, 2.96 mmol) in methanol (5 mL) in a 60° C. oil bath. After 15 h, the reaction was concentrated in vacuo and the residue was purified by repeated FC using a gradient of 50-100% ethyl acetate in hexanes to give first 4-(5-benzyl-1-ethyl-(1H)-pyrazol-3-yl)-1-(t-butoxycarbonyl)piperidine (0.148 g total) as the higher Rf product isomer and then the title compound (0.373 g total) as the lower Rf.

Provenance & Evidence