Formaldehyde → 1,1-Dimethylethyl (2S)-2-methyl-4-{[4-(methylamino)phenyl]methyl}-1-piperazinecarboxylate

HRID 883783Notes

Reaction equation

HRID 883783 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][N:9]2[CH2:14][CH2:13][N:12]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[C@@H:11]([CH3:22])[CH2:10]2)=[CH:4][CH:3]=1.[CH2:23]=O.C[O-].[Na+].[BH4-].[Na+]>CO.CC(C)=O>[CH3:22][C@H:11]1[CH2:10][N:9]([CH2:8][C:5]2[CH:6]=[CH:7][C:2]([NH:1][CH3:23])=[CH:3][CH:4]=2)[CH2:14][CH2:13][N:12]1[C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16]

Participants

7

Procedure

To 1,1-dimethylethyl (2S)-4-[(4-aminophenyl)methyl]-2-methyl-1-piperazinecarboxylate (D22) (4.14 g, 13.56 mmol) in dry MeOH (80 mL) at 50° C. under an argon atmosphere was added paraformaldehyde (1.22 g, 40.67 mmol) and sodium methoxide (3.65 g, 67.78 mmol). The mixture was stirred for ˜24 h then sodium borohydride (1.54 g, 40.67 mmol) was added portion-wise and the reaction stirred at 50° C. overnight. After cooling to room temperature, acetone (10 mL) was added and the solvent removed in vacuo. The residue was partitioned between DCM and water and the organic phase was washed with brine, then dried and concentrated. Column chromatography gave the title compound as a colourless, crystalline solid (3.73 g). δH (CDCl3, 400 MHz) 7.13 (2H, d), 6.57 (2H, d), 4.16 (1H, br.s), 3.78 (1H, d), 3.67 (1H, br.s), 3.42 (1H, d), 3.30 (1H, d), 3.08 (1H, td), 2.83 (3H, s), 2.75 (1H, m), 2.59 (1H, m), 2.06 (1H, dd), 1.94 (1H, m), 1.45 (9H, s), 1.21 (3H, d).

Workup

  1. stirringthe reaction stirred at 50° C. overnight
  2. customthe solvent removed in vacuo
  3. customThe residue was partitioned between DCM and water
  4. washthe organic phase was washed with brine
  5. customdried
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-33c354e6f826490a9ce9bd51d07383d7
Source dataset
uspto-grants-2012_08
Patent number
US08236953B2

Reaction notes

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