Reaction #48038

Reaction equation

1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxamidine

HCl

4-fluorophenylsulfonyl chloride

triethylamine

→

N-[(4-fluorophenyl)sulfonyl]-1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxamidine

Yield 54.0%

Solvents

acetonitrile

Conditions

Workup

1. 1
   ConcentrationAfter concentration in vacuo
2. 2
   workup.DISSOLUTIONthe residue is dissolved in a mixture of Ethyl acetate and water
3. 3
   OtherThe Ethyl acetate layer is collected
4. 4
   Dryingdried over MgSO4
5. 5
   Filtrationfiltered
6. 6
   Concentrationconcentrated in vacuo
7. 7
   OtherThe resulting residue is recrystallised from methyl-t-butyl ether

Procedure

Part B: To a stirred solution of 1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxamidine.HCl (1.87 gram, 5 mmol) and 4-fluorophenylsulfonyl chloride (0.97 g, 5 mmol) in anhydrous acetonitrile (20 ml) is added triethylamine (2.1 ml, 15 mmol) and the resulting mixture is stirred at room temperature for 16 hours. After concentration in vacuo, the residue is dissolved in a mixture of Ethyl acetate and water. The Ethyl acetate layer is collected, dried over MgSO4, filtered and concentrated in vacuo. The resulting residue is recrystallised from methyl-t-butyl ether to give N-[(4-fluorophenyl)sulfonyl]-1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxamidine (1.22 gram, 54% yield). Melting point: 200-203.5° C.

Source