Water → tert-Butyl 4-ethyl-3-oxopiperazine-1-carboxylate

HRID 1429755Notes

Reaction equation

HRID 1429755 reaction equation
[O:1]=[C:2]1[NH:7][CH2:6][CH2:5][N:4]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[CH2:3]1.[H-].[Na+].I[CH2:18][CH3:19].O>CN(C=O)C.C(OCC)C.C(OCC)(=O)C>[CH2:18]([N:7]1[CH2:6][CH2:5][N:4]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[CH2:3][C:2]1=[O:1])[CH3:19]

Participants

8

Reactant 4

HCID 962WaterHCID 6340IodoethaneHCID 24758Sodium hydrideHCID 3157178Tert-butyl 3-oxopiperazine-1-carboxylate

Product 1

HCID 18783917tert-Butyl 4-ethyl-3-oxopiperazine-1-carboxylate

Reagents, catalysts & solvents 3

HCID 3283Diethyl EtherSolventHCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

To a slurry of tert-butyl 3-oxopiperazine-1-carboxylate (10 g, 49.9 mmol) in 250 mL of DMF, NaH (60% in mineral oil) (2.1 g, 52.4 mmol) was added in portions. The mixture was stirred for 15 min after completion of addition, cooled to 0° C. and iodoethane (5.62 mL, 69.92 mmol) slowly added over ˜3 min. The resultant suspension was stirred at rt for 2 h. Water was slowly added (400 mL) and then 250 mL of 1:1 ethyl acetate:diethyl ether. The layers were separated and then the organic phase was washed with brine, dried over sodium sulfate, filtered and concentrated to afford tert-butyl 4-ethyl-3-oxopiperazine-1-carboxylate as a colorless oil weighing 6.4 g which was used directly in the next step.

Workup

  1. additionafter completion of addition
  2. customThe layers were separated
  3. washthe organic phase was washed with brine
  4. dry with materialdried over sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-00a9084c071a477289fc1b2049698ae7
Source dataset
uspto-grants-2015_01
Patent number
US08940744B2

Reaction notes

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