Reaction #312611

Reaction equation

4-benzyl-1-(3-fluoro-2-carboxyphenyl)-piperazine

hydrazine

→

title compound

Yield 53.0%

4-(4-Benzylpiperazin-1-yl)-1H-indazole

Yield 53.0%

Solvents

ether

dimethylsulfoxide

Conditions

Workup

1. 1
   OtherThe cooled reaction
2. 2
   Washwashed with a mixture of water and saturated aqueous sodium bicarbonate
3. 3
   WashThe organic layer is further washed sequentially with water and brine
4. 4
   Dryingdried over MgSO4
5. 5
   Concentrationconcentrated in vacuo
6. 6
   Otherto give a residue
7. 7
   OtherThe residue is chromatographed
8. 8
   Otherto give a white foam which
9. 9
   OtherThe resulting white powder is isolated by suction filtration
10. 10
    Washwashed with hexane

Procedure

A stirred solution of 4-benzyl-1-(3-fluoro-2-carboxyphenyl)-piperazine (5.96 g, 20.0 mmol) in dimethylsulfoxide (10 mL) and hydrazine (10 mL) is heated at 95° C. under nitrogen for 4 days. The cooled reaction is diluted with ether and washed with a mixture of water and saturated aqueous sodium bicarbonate. The organic layer is further washed sequentially with water and brine dried over MgSO4 and concentrated in vacuo to give a residue. The residue is chromatographed using ethyl acetate as the eluant. The resulting oil is reconcentrated from ether to give a white foam which is stirred under hexanes/ether overnight. The resulting white powder is isolated by suction filtration and washed with hexane to give the title compound 3.11 g, (53% yield), identified by HNMR.

Source