Triethylamine → 4-(3-Methyl-2-nitrophenyl)-piperazine-1-carboxylic acid tert-butyl ester

HRID 1005652

Reaction equation

HRID 1005652 reaction equation
[CH3:1][C:2]1[C:3]([N+:16]([O-:18])=[O:17])=[C:4](OS(C(F)(F)F)(=O)=O)[CH:5]=[CH:6][CH:7]=1.[C:19]([O:23][C:24]([N:26]1[CH2:31][CH2:30][NH:29][CH2:28][CH2:27]1)=[O:25])([CH3:22])([CH3:21])[CH3:20].C(N(CC)CC)C>C(#N)C>[C:19]([O:23][C:24]([N:26]1[CH2:31][CH2:30][N:29]([C:4]2[CH:5]=[CH:6][CH:7]=[C:2]([CH3:1])[C:3]=2[N+:16]([O-:18])=[O:17])[CH2:28][CH2:27]1)=[O:25])([CH3:22])([CH3:20])[CH3:21]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 143452tert-Butyl piperazine-1-carboxylateHCID 158695523-Methyl-2-nitrophenyl trifluoromethanesulphonate

Product 1

HCID 601087754-(3-Methyl-2-nitrophenyl)-piperazine-1-carboxylic acid tert-butyl esterYield 37.5%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

Trifluoromethanesulfonic acid 3-methyl-2-nitrophenyl ester (26.7 g, 93.6 mmol), 1-tert-butoxycarbonyl piperazine (17 g, 91.3 mmol) and triethylamine (14 mL, 100 mmol) in 250 mL of acetonitrile was heated under reflux for 25 h. The mixture was concentrated in vacuo, diluted with water and extracted with ether. The ether was washed with aqueous ammonium hydroxide and brine, dried, and evaporated. Purification by silica gel chromatography (10% ethyl acetate-hexane) afforded 11 g of 4-(3-methyl-2-nitrophenyl)-piperazine-1-carboxylic acid tert-butyl ester as a golden solid, m.p. 101-102° C.

Workup

  1. temperatureunder reflux for 25 h
  2. concentrationThe mixture was concentrated in vacuo
  3. additiondiluted with water
  4. extractionextracted with ether
  5. washThe ether was washed with aqueous ammonium hydroxide and brine
  6. customdried
  7. customevaporated
  8. customPurification by silica gel chromatography (10% ethyl acetate-hexane)

Sources & evidence

ORD record
ord-fef11ca5a52242f8bab6da1a7db8c076
Source dataset
uspto-grants-2004_09
Patent number
US06787535B2

Linked notes

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