Piperazine → 3-(1-Piperazinyl)-1,2-benzisothiazole

HRID 1873063Notes

Reaction equation

HRID 1873063 reaction equation
[NH:1]1[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.C([C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=1[S:15][N:16]1[CH2:21]CNCC1)#N>C(O)(C)C>[N:1]1([C:21]2[C:11]3[CH:12]=[CH:13][CH:14]=[CH:9][C:10]=3[S:15][N:16]=2)[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1

Participants

4

Reactant 2

HCID 4837Piperazine2×HCID 186886442-[(Piperazin-1-yl)sulfanyl]benzonitrile

Product 1

HCID 27721443-(1-Piperazinyl)-1,2-benzisothiazoleYield 55%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent2×

Conditions

Temperature
90 °C

Procedure

Anhydrous piperazine (17.2 g, 0.20 mol) and isopropanol (3.0 mL) were charged to a round bottom flask equipped with a mechanical stirrer, thermometer, condenser topped with a nitrogen inlet, and an addition tunnel. Once the flask was purged and then maintained under nitrogen, the mixture was heated to 90° C. to afford a solution. A solution of 1-(2-cyanophenylthio)piperazine (4.38 g, 20.0 mmol) in isopropanol (2.0 mL) was slowly added to the warm piperazine solution over 1 hour. Once the addition was complete, the solution was heated to reflux (118° C.) for 24 hours. The reddish solution was cooled to room temperature and then analyzed by HPLC. 3-(1-Piperazinyl)-1,2-benzisothiazole was formed in 55% yield by HPLC assay.

Workup

  1. customequipped with a mechanical stirrer
  2. customthermometer, condenser topped with a nitrogen inlet
  3. customOnce the flask was purged
  4. temperaturemaintained under nitrogen
  5. customto afford a solution
  6. additionOnce the addition
  7. temperaturethe solution was heated
  8. temperatureto reflux (118° C.) for 24 hours
  9. temperatureThe reddish solution was cooled to room temperature

Sources & evidence

ORD record
ord-01a74e72d2ac4f559765f0cd34ac33ec
Source dataset
uspto-grants-2000_08
Patent number
US06111105

Reaction notes

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