Pyridine → 1-cyclopentyl-3-phenylmethyl-4-cyano-5-(phenylmethylcarbonylamino)-1H-pyrazole

Participants

Reaction Steps

To a stirred solution of 1-cyclopentyl-3-phenylmethyl-5-amino-1H-pyrazole-4-carbonitrile (2.3 g, 8.6 mmol), CHCl3 (50 ml) and pyridine (20 ml) in an ice bath was added a solution of phenylacetyl chloride (2.3 ml, 17.2 mmol) in CHCl3 (10 ml) over a period of 20 minutes. The reaction mixture was stirred in an ice bath for 3 hours, then at room temperature for 2 hours. The solvent was removed in vacuo, the residue was partitioned between CHCl3 (100 ml) and water (50 ml), and the organic layer was separated. Concentration of the organic layer afforded a gummy solid which was recrystallized from isopropanol to afford 1.1 g (88%) of 1-cyclopentyl-3-phenylmethyl-4-cyano-5-(phenylmethylcarbonylamino)-1H-pyrazole, as white needles, m.p. 166°-168° C.

Provenance & Evidence