4-Nitrobenzaldehyde → 1,1-Dimethylethyl (2S)-2-methyl-4-[(4-nitrophenyl)methyl]-1-piperazinecarboxylate

HRID 883778Notes

Reaction equation

HRID 883778 reaction equation
[N+:1]([C:4]1[CH:11]=[CH:10][C:7]([CH:8]=O)=[CH:6][CH:5]=1)([O-:3])=[O:2].[CH3:12][C@H:13]1[CH2:18][NH:17][CH2:16][CH2:15][N:14]1[C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C([O-])(O)=O.[Na+]>ClCCCl>[CH3:12][C@H:13]1[CH2:18][N:17]([CH2:8][C:7]2[CH:10]=[CH:11][C:4]([N+:1]([O-:3])=[O:2])=[CH:5][CH:6]=2)[CH2:16][CH2:15][N:14]1[C:19]([O:21][C:22]([CH3:23])([CH3:25])[CH3:24])=[O:20]

Participants

6

Reactant 4

HCID 5414-NitrobenzaldehydeHCID 516892Sodium BicarbonateHCID 5049666Sodium triacetoxyborohydrideHCID 10081508tert-Butyl (2S)-2-methylpiperazine-1-carboxylate

Product 1

HCID 592622041,1-Dimethylethyl (2S)-2-methyl-4-[(4-nitrophenyl)methyl]-1-piperazinecarboxylateYield 91.1%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

A mixture of 4-nitrobenzaldehyde (30.22 g, 0.2 mol), 1-dimethylethyl (2S)-2-methyl-1-piperazinecarboxylate (40.06 g, 0.2 mol) and sodium tri(acetoxy)borohydride (85 g, 0.4 mol) in 1,2-DCE (1 L) was stirred at room temperature over-weekend. The reaction mixture was treated portion-wise with NaHCO3 solution (400 mL) over a period of ˜2 h. After a further 30 minutes, the organic layer was separated, washed with brine, dried and concentrated to give a viscous pale yellow oil. Purification by column chromatography eluting with 0%, 10% and then 20% EtOAc/hexane yielded the title compound as a yellow crystalline solid (61.1 g).

Workup

  1. customthe organic layer was separated
  2. washwashed with brine
  3. customdried
  4. concentrationconcentrated
  5. customto give a viscous pale yellow oil
  6. customPurification by column chromatography
  7. washeluting with 0%, 10%

Sources & evidence

ORD record
ord-8b76797ba5f84e699a39a7aab62fd81b
Source dataset
uspto-grants-2012_08
Patent number
US08236953B2

Reaction notes

Loading…