N-BOC-ethylenediamine → HCID 178453698, compound

Participants

Reaction Steps

5.0 g (23.12 mmol) of ethyl 4-phenyl-3-pyrazolecarboxylate were heated to 120° under reduced pressure for 2 hours with 7.4 g (46.19 mmol) of t-butyl (2-aminoethyl)carbamate, whereby the ethanol formed was distilled off continuously. The reaction mixture was then taken up in methylene chloride and chromatographed on 150 g of silica gel with 9:1, 8:2 and 7:3 mixture of methylene chloride and ethyl acetate as the eluting agent. The fractions which were pure according to the thin-layer chromatogram were combined and evaporated, ant the residue was crystallized from ethyl acetate/hexane, whereby there were obtained 5.1 g (66.8%) to t-butyl [2-(4-phenylpyrazole-3-carboxamido)ethyl]carbamate as white crystals, melting point 71°/162°-163° (still containing 0.05 mol of hexane).

Provenance & Evidence