Hydrochloric Acid → 1-(4-chlorophenyl)-N-methyl-5-phenyl-N''-(piperidin-1-ylsulfonyl)-4,5-dihydro-1H-pyrazole-3-carboximidamide

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Reaction Conditions

Reaction Steps

Part B: A stirred mixture of N-[(piperidin-1-yl)sulfonyl]-1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxamide (2.23 gram, 5 mmol), PCl5 (1.15 g, 5.5 mmol) and chlorobenzene (50 ml) is heated for 90 minutes at 140° C. After cooling the mixture to room temperature, followed by concentration in vacuo, the residue is dissolved in dichloromethane and methylamine.HCl (0.34 g, 5 mmol) and DIPEA (1.74 ml, 10 mmol) are successively added. The resulting mixture is stirred for 1 hour at room temperature, twice washed with water, dried over MgSO4, filtered and concentrated in vacuo. The resulting residue is further purified by flash chromatography (silica gel, dichloromethane), followed by crystallization from diisopropyl ether to give N-[(piperidin-1-yl)sulfonyl]-N′-methyl-1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxamidine (1.12 gram, 49% yield). Melting point: 141-144° C. Rf (silica gel, diethyl ether=0.2).

Provenance & Evidence