Methanol → Methyl 2-(piperazin-1-yl)benzoate

HRID 1810955Notes

Reaction equation

HRID 1810955 reaction equation
[N:1]1([C:7]2[CH:15]=[CH:14][CH:13]=[CH:12][C:8]=2[C:9]([OH:11])=[O:10])[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.OS(O)(=O)=O.[CH3:21]O>>[CH3:21][O:10][C:9](=[O:11])[C:8]1[CH:12]=[CH:13][CH:14]=[CH:15][C:7]=1[N:1]1[CH2:2][CH2:3][NH:4][CH2:5][CH2:6]1

Participants

4

Reactant 3

HCID 887Methanol3×HCID 1118Sulfuric Acid3×HCID 27604322-(1-Piperazinyl)benzoic acid

Product 1

HCID 10932975Methyl 2-(piperazin-1-yl)benzoateYield 63%

Procedure

2-Piperazin-1-yl-benzoic acid (1.000 g, 4.89 mmol) is suspended in 10 mL of MeOH. To this is added 5 mL of conc. H2SO4. The mixture is stirred for 16 h resulting in a white precipitate. An additional 5 mL of H2SO4 is added with an additional 10 mL of MeOH. The reaction volume is increased by an additional 200 mL of MeOH and 60 mL of H2SO4 and the mixture is stirred an additional 2 h and then heated at reflux for 12 h. The reaction volume is then reduced to approximately 175 mL and applied to an ion exchange column, eluting with 5×200 mL of 10% NH3/MeOH and then the product fractions are concentrated. The eluent is co-evaporated with toluene to remove residual water to give 0.667 g of 2-piperazin-1-yl-benzoic acid methyl ester in 63% yield.

Workup

  1. customresulting in a white precipitate
  2. stirringthe mixture is stirred an additional 2 h
  3. temperatureheated
  4. temperatureat reflux for 12 h
  5. washeluting with 5×200 mL of 10% NH3/MeOH
  6. concentrationthe product fractions are concentrated
  7. customto remove residual water

Sources & evidence

ORD record
ord-53273b22ef6f4a368669aca7b37618a6
Source dataset
uspto-grants-2013_01
Patent number
US08362249B2

Reaction notes

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