Triethylamine → tert-Butyl 4-(5-methyl-1,2,4-oxadiazol-3-yl)piperazine-1-carboxylate

HRID 400446Notes

Reaction equation

HRID 400446 reaction equation
[CH2:1]([N:3](CC)CC)[CH3:2].Cl.N[OH:10].[C:11]([O:15][C:16]([N:18]1[CH2:23][CH2:22][N:21]([C:24]#[N:25])[CH2:20][CH2:19]1)=[O:17])([CH3:14])([CH3:13])[CH3:12]>C(O)C>[C:11]([O:15][C:16]([N:18]1[CH2:19][CH2:20][N:21]([C:24]2[N:3]=[C:1]([CH3:2])[O:10][N:25]=2)[CH2:22][CH2:23]1)=[O:17])([CH3:14])([CH3:12])[CH3:13]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 443297Hydroxyamine hydrochlorideHCID 14068968tert-Butyl 4-cyanopiperazine-1-carboxylate

Product 1

HCID 86686046tert-Butyl 4-(5-methyl-1,2,4-oxadiazol-3-yl)piperazine-1-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
80 °C

Procedure

5.3 mL triethylamine and 2.6 g hydroxylamine hydrochloride were added to 6.8 g 4-cyano-piperazine-1-carboxylic acid tert-butyl ester in 50 mL ethanol. The reaction was stirred 2 h at 80° C. The solvent was removed and 50 mL pyridine and 3.7 mL acetic anhydride were added to the residue and stirred at 80° C. over night. The mixture was evaporated. Water was added and the precipitate was filtered and purified by chromatography on silica gel (cyclohexane/ethyl acetate: 2/1) to give 3.35 g of the desired product.

Workup

  1. customThe solvent was removed
  2. addition50 mL pyridine and 3.7 mL acetic anhydride were added to the residue
  3. stirringstirred at 80° C. over night
  4. customThe mixture was evaporated
  5. additionWater was added
  6. filtrationthe precipitate was filtered
  7. custompurified by chromatography on silica gel (cyclohexane/ethyl acetate: 2/1)

Sources & evidence

ORD record
ord-fbc49833b773451fa2050ad6ed50af7c
Source dataset
uspto-grants-2014_06
Patent number
US08741892B2

Reaction notes

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