Tetrahydrofuran → di-tert-butyl (2S)-2-(((2-methylpropyl)amino)methyl)-1,4-piperazinedicarboxylate

HRID 1972600Notes

Reaction equation

[CH3:1][CH:2]([CH3:27])[CH2:3][NH:4][C:5]([C@H:7]1[CH2:12][N:11]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:10][CH2:9][N:8]1[C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])=O.B.C1COCC1.C1COCC1>CO>[CH3:1][CH:2]([CH3:27])[CH2:3][NH:4][CH2:5][C@H:7]1[CH2:12][N:11]([C:13]([O:15][C:16]([CH3:17])([CH3:18])[CH3:19])=[O:14])[CH2:10][CH2:9][N:8]1[C:20]([O:22][C:23]([CH3:24])([CH3:26])[CH3:25])=[O:21]

Participants

Conditions

Temperature: 50 °C

Procedure

A 500-mL round-bottomed flask was charged with di-tert-butyl (2R)-2-((2-methylpropyl)carbamoyl)-1,4-piperazinedicarboxylate (1.77 g, 4.60 mmol), BH3.THF (1.0 M in THF, 13.8 mL, 13.8 mmol, Sigma-Aldrich, St. Louis, Mo.) and THF (60 mL). The reaction mixture was heated at 50° C. for 12 h. The mixture was allowed to cool to room temperature and then MeOH was added until the bubbling ceased. The reaction mixture was concentrated and the crude product was purified by silica gel chromatography (100 g of silica gel, 0 to 10% iPrOH (with 10% NH4OH) in CHCl3) to obtain di-tert-butyl (2S)-2-(((2-methylpropyl)amino)methyl)-1,4-piperazinedicarboxylate (0.939 g) as a clear oil which solidified upon standing.

Workup

temperatureto cool to room temperature
concentrationThe reaction mixture was concentrated
customthe crude product was purified by silica gel chromatography (100 g of silica gel, 0 to 10% iPrOH (with 10% NH4OH) in CHCl3)

Sources & evidence

ORD record: ord-3bc660ff9a6f407baf3685a8a727e0c6
Source dataset: uspto-grants-2013_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08431563B2

Reaction notes

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