Benzyl Bromide → Tert-butyl 4-benzyl-3-oxopiperazine-1-carboxylate

HRID 609644Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][C:10](=[O:14])[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[H-].[Na+].[CH2:17](Br)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1>CN(C=O)C>[CH2:17]([N:11]1[CH2:12][CH2:13][N:8]([C:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])=[O:7])[CH2:9][C:10]1=[O:14])[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

Participants

Conditions

Temperature: 60 °C

Procedure

To a stirred solution solution of Intermediate 1 (1.5 g, 7.5 mmol) in DMF (30 mL) at 0° C., under nitrogen, was added sodium hydride (330 mg of a 60% dispersion in mineral oil. 8.3 mmol). The solution was stirred for 90 min before benzyl bromide (1.16 mL, 9.8 mmol) was added. The solution was heated at 60° C. for 3 h then the solvent was removed in vacuo. The residue was partitioned between EtOAc (2×50 mL) and water (50 mL). The combined organic phases were dried (Na2SO4) and evaporated. The residue was chromatographed on silica, eluting with petrol:EtOAc (1:1), to afford the title amide (2.11 g, 97%) as a colourless solid. m.p. 85-88° C., 1H NMR (250 MHz, CDCl3) δ 1.46 (9H, s), 3.23-3.28 (2H, m), 3.56-3.61 (2H, m), 4.16 (2H, s), 4.63 (2H, s), 7.24-7.35 (5H, m).

Workup

additionwas added
customthe solvent was removed in vacuo
customThe residue was partitioned between EtOAc (2×50 mL) and water (50 mL)
dry with materialThe combined organic phases were dried (Na2SO4)
customevaporated
customThe residue was chromatographed on silica
washeluting with petrol:EtOAc (1:1)

Sources & evidence

ORD record: ord-18b6f11b6f284f36b36e31f4de70ec5b
Source dataset: uspto-grants-1999_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05998415

Reaction notes

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