Triethylamine → Ethyl 3-oxopiperazine-1-carboxylate

HRID 1622879Notes

Reaction equation

HRID 1622879 reaction equation
[NH:1]1[CH2:6][CH2:5][NH:4][CH2:3][C:2]1=[O:7].C(N(CC)CC)C.Cl[C:16]([O:18][CH2:19][CH3:20])=[O:17]>C(Cl)Cl>[O:7]=[C:2]1[NH:1][CH2:6][CH2:5][N:4]([C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH2:3]1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 10928Ethyl chloroformateHCID 231360Piperazin-2-one

Product 1

HCID 13190471Ethyl 3-oxopiperazine-1-carboxylateYield 58.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2-piperazinone (5.0 g, 50.0 mmol) and triethylamine (11.09 g, 110.0 mmol) in DCM (15 mL) is added ethyl chloroformate (5.9 g, 55.0 mmol) at room temperature and the reaction mixture is stirred for 2 h. The reaction is quenched with water (100 mL) and extracted with DCM (3×100 mL). The combined organic layers are dried over anhydrous sodium sulphate, filtered and concentrated in vacuo. The residue is triturated with Et2O to give the title compound (5.0 g, 29.05 mmol) as a pale yellow solid. 1H-NMR (400 MHz, DMSO-d6): δ 1.19 (t, 3H), 3.16-3.19 (m, 2H), 3.48-3.51 (m, 2H), 3.85 (s, 2H), 4.05 (q, 2H), 8.06 (s, 1H).

Workup

  1. customThe reaction is quenched with water (100 mL)
  2. extractionextracted with DCM (3×100 mL)
  3. dry with materialThe combined organic layers are dried over anhydrous sodium sulphate
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customThe residue is triturated with Et2O

Sources & evidence

ORD record
ord-478a814149ce44beb6d60a854e4e14c4
Source dataset
uspto-grants-2014_07
Patent number
US08778946B2

Reaction notes

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