Methyl iodide → Ethyl 1,4-dibenzyl-2-methylpiperazine-2-carboxylate

HRID 502526Notes

Reaction equation

[CH2:1]([N:8]1[CH2:13][CH2:12][N:11]([CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[CH2:10][CH:9]1[C:21]([O:23][CH2:24][CH3:25])=[O:22])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Li+].[CH3:27]C([N-]C(C)C)C.CI>C1COCC1>[CH2:1]([N:8]1[CH2:13][CH2:12][N:11]([CH2:14][C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=2)[CH2:10][C:9]1([CH3:27])[C:21]([O:23][CH2:24][CH3:25])=[O:22])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

Conditions

Temperature: -78 °C

Procedure

To ethyl 1,4-dibenzylpiperazine-2-carboxylate (35.4 g, 0.1 mol) in THF(200 mL) cooled to −78° C. was added dropwise LDA (64 mL, 1.8 M). The reaction was stirred at −78° C. for 1 h then MeI (7.2 mL, 0.11 mol) was added. The reaction was allowed to slowly warm to RT then quenched with sat'd NH4Cl. Water (200 mL) was added and the residue was extracted with EtOAc (200 mL). The EtOAc layer was washed twice with water then the solvent was removed in vacuo. Silica gel chromatography provided ethyl 1,4-dibenzyl-2-methylpiperazine-2-carboxylate (compound 10A) 14.91 g. HPLC RT: 2.42 min (Chromolith SpeedROD 4.6×50 mm, 10-90% aqueous MeOH over 4 minutes containing 0.1% TFA, 4 ml/min, monitoring at 220 nm). (M+H)+:353.

Workup

temperatureto slowly warm to RT
customthen quenched with sat'd NH4Cl
additionWater (200 mL) was added
extractionthe residue was extracted with EtOAc (200 mL)
washThe EtOAc layer was washed twice with water
customthe solvent was removed in vacuo

Sources & evidence

ORD record: ord-9752f1828ec54e8483a9493af4f20d3d
Source dataset: uspto-grants-2010_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07776859B2

Reaction notes

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