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

HRID 280532Notes

Reaction equation

HRID 280532 reaction equation
[NH:1]1[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.Cl[C:8]1[C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=2[S:10][N:9]=1.[OH-].[Na+]>>[S:10]1[C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=2[C:8]([N:1]2[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]2)=[N:9]1

Participants

4

Reactant 3

HCID 4837PiperazineHCID 14798Sodium HydroxideHCID 5981903-Chloro-1,2-benzisothiazole

Product 1

HCID 27721443-(1-Piperazinyl)-1,2-benzisothiazoleYield 91.1%

Procedure

A 4 L suction flask was charged with anhydrous piperazine (1582 g, 18.36 moles) followed by molten 3-chloro-1,2-benzisothiazole (Example 8, 622 g, 3.672 moles). The flask was stoppered with a wired-on rubber stopper and a short length of pressure tubing was wired-on to the side tube. The flask was evacuated (house vacuum) and the pressure tubing on the side arm clamped shut. The apparatus was then oven heated at 125° with occasional swirling as melting proceeded. After 24 hours at this temperature, the orange melt was quenched in 4.8 liter of cracked ice and water. One equivalent of 50% NaOH (293 g, 3.672 moles) was added in one portion. The mixture was extracted with methylene chloride and these extracts washed with water. Concentration in vacuo gave 734 g of crude product which was recrystallized from 1800 mL of boiling ethyl acetate to yield 548 g, 68%, m.p. 88°-90°.

Workup

  1. customThe flask was evacuated (house vacuum)
  2. temperatureoven heated at 125°
  3. customthe orange melt was quenched in 4.8 liter of cracked ice
  4. extractionThe mixture was extracted with methylene chloride
  5. washthese extracts washed with water
  6. concentrationConcentration in vacuo

Sources & evidence

ORD record
ord-1fdcc98bff5c4f8e9e887725ccce9058
Source dataset
uspto-grants-1986_05
Patent number
US04590196

Reaction notes

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