Dichloromethane → Benzyl 4-propionylpiperazine-1-carboxylate

HRID 922379Notes

Reaction equation

HRID 922379 reaction equation
[N:1]1([C:7]([O:9][CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[O:8])[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.C(N(CC)CC)C.C(Cl)Cl.[C:27](Cl)(=[O:30])[CH2:28][CH3:29]>O>[C:27]([N:4]1[CH2:5][CH2:6][N:1]([C:7]([O:9][CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[O:8])[CH2:2][CH2:3]1)(=[O:30])[CH2:28][CH3:29]

Participants

6

Reactant 4

HCID 6344DichloromethaneHCID 8471TriethylamineHCID 62324Propionyl chlorideHCID 643495Benzyl piperazine-1-carboxylate

Product 1

HCID 22596214Benzyl 4-propionylpiperazine-1-carboxylateYield 72.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A solution of benzyl piperazine-1-carboxylate (16, 10.0 g, 45.4 mmol), triethylamine (6.89 g, 68.0 mmol) and dry CH2Cl2 (150 mL) was cooled to 0° C. and propionyl chloride (4.62 g, 50.0 mmol) was added dropwise over 10 min. The reaction was kept under nitrogen and allowed to warm to room temperature. After stirring at rt for 17 h, water (50 mL) was added and the aqueous layer was extracted with CH2Cl2 (2×50 mL). The solution was dried over Na2SO4, filtered and concentrated to a yellow oil. The product was purified by silica gel chromatography eluting with 0-3% CH3OH in CH2Cl2 to afford the title compound (9.08 g, 72%) as a clear, colorless oil: 1H NMR (500 MHz, CDCl3) δ 7.40-7.30 (m, 5H), 5.15 (s, 2H), 3.70-3.35 (m, 8H), 2.35 (q, J=7.5 Hz, 2H), 1.15 (t, J=7.5 Hz, 3H).

Workup

  1. extractionthe aqueous layer was extracted with CH2Cl2 (2×50 mL)
  2. dry with materialThe solution was dried over Na2SO4
  3. filtrationfiltered
  4. concentrationconcentrated to a yellow oil
  5. customThe product was purified by silica gel chromatography
  6. washeluting with 0-3% CH3OH in CH2Cl2

Sources & evidence

ORD record
ord-970600ede3a1447ab23b0073e552bb04
Source dataset
uspto-grants-2016_03
Patent number
US09278940B2

Reaction notes

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