Reaction #312613

Reaction equation

1-phenylsulfonyl-4-(4-benzylpiperazin-1-yl)-1H-indazole

1-chloroethyl chloroformate

→

title compound

Yield 63.0%

1-(Phenylsulfonyl)-4-(1-piperazinyl)-1H-indazole hydrochloride

Yield 63.0%

Solvents

1,2-dichloroethane

Conditions

Workup

1. 1
   Temperatureheated
2. 2
   Temperatureat reflux temperature for 2 hr
3. 3
   Concentrationconcentrated in vacuo
4. 4
   TemperatureThe resultant residue is heated
5. 5
   Temperatureat reflux temperature in methanol for 1.5 hr
6. 6
   Temperaturecooled
7. 7
   Concentrationconcentrated in vacuo
8. 8
   OtherThe resulting tan solid is triturated with ether
9. 9
   Othercrystallized from hot ethanol

Procedure

A solution of 1-phenylsulfonyl-4-(4-benzylpiperazin-1-yl)-1H-indazole (433 mg, 1.0 mmol) in 1,2-dichloroethane is treated with 1-chloroethyl chloroformate (0.27 mL, 2.5 mmol) heated at reflux temperature for 2 hr, and concentrated in vacuo. The resultant residue is heated at reflux temperature in methanol for 1.5 hr, cooled, concentrated in vacuo and reconcentrated from ether. The resulting tan solid is triturated with ether and crystallized from hot ethanol to give the title compound as a tan solid 237 mg (63% yield), mp 203-205° C., identified by HNMR and mass spectral analyses.

Source