Trifluoroacetic acid → 1-(Methylsulfonyl)piperazine

HRID 2300925Notes

Reaction equation

HRID 2300925 reaction equation
C(OC([N:8]1[CH2:13][CH2:12][N:11]([S:14]([CH3:17])(=[O:16])=[O:15])[CH2:10][CH2:9]1)=O)(C)(C)C.FC(F)(F)C(O)=O>C(Cl)Cl>[CH3:17][S:14]([N:11]1[CH2:12][CH2:13][NH:8][CH2:9][CH2:10]1)(=[O:16])=[O:15]

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 4496004Tert-butyl 4-(methylsulfonyl)piperazine-1-carboxylate

Product 1

HCID 7091611-(Methylsulfonyl)piperazineYield 41.6%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

N-tert-butoxycarbonyl-N′-methylsulfonylpiperazine (3.84 g, 14.5 mmol) was suspended in methylene chloride (100 mL) under nitrogen and trifluoroacetic acid (10 mL) was added. After 3 hours, the reaction mixture was concentrated in vacuo and the residue dissolved in water (150 mL). The aqueous layer was washed with ether (2×75 mL). The pH of the aqueous layer was then adjusted to 10 and it was extracted with methylene chloride (3×120 mL). The methylene chloride layers were dried over magnesium sulfate, and concentrated in vacuo to give 0.99 g of N-methylsulfonylpiperazine. Further extraction of the aqueous layer with 10% methanol/methylene chloride (3×120 mL) afforded 0.44 g of N-methylsulfonylpiperazine, for a total of 1.43 g (59%).

Workup

  1. concentrationthe reaction mixture was concentrated in vacuo
  2. dissolutionthe residue dissolved in water (150 mL)
  3. washThe aqueous layer was washed with ether (2×75 mL)
  4. extractionwas extracted with methylene chloride (3×120 mL)
  5. dry with materialThe methylene chloride layers were dried over magnesium sulfate
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-36ea584659d04aa8a71a07a31d58f236
Source dataset
uspto-grants-2002_12
Patent number
US06498185B1

Reaction notes

Loading…