(R)-Tert-butyl 4-benzyl-2-methylpiperazine-1-carboxylate → tert-Butyl (2R)-2-methylpiperazine-1-carboxylate

HRID 1585146Notes

Reaction equation

HRID 1585146 reaction equation
C([N:8]1[CH2:13][CH2:12][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[C@H:10]([CH3:21])[CH2:9]1)C1C=CC=CC=1>[OH-].[OH-].[Pd+2].C(O)C>[CH3:21][C@@H:10]1[CH2:9][NH:8][CH2:13][CH2:12][N:11]1[C:14]([O:16][C:17]([CH3:18])([CH3:20])[CH3:19])=[O:15]

Participants

4

Reactant 1

HCID 10085634(R)-Tert-butyl 4-benzyl-2-methylpiperazine-1-carboxylate

Product 1

HCID 10262201tert-Butyl (2R)-2-methylpiperazine-1-carboxylate

Reagents, catalysts & solvents 2

HCID 9942167Palladium hydroxideCatalystHCID 702EthanolSolvent

Procedure

A mixture of tert-butyl 4-benzyl-(2R)-methyl-1-piperazinecarboxylate (XXII, 5.40 g), ethanol (200 ml) and Pearlman's catalyst (1.36 g) is hydrogenated (36 psi) for 16 hr at 20-25° in a Parr flask. The mixture is filtered and the solids washed successively with ethanol, methylene chloride and methanol. The combined filtrates are concentrated, diluted with methylene chloride, filtered, and concentrated to give the title compound which solidified upon standing, mp 33-36°; [α]25D -59° (CHCl3); IR (mineral oil) 1695, 1408, 1363, 1301, 1226, 1173 and 1095 cm-1 ; NMR (CDCl3) 4.1-4.3, 3.7-3.85, 2.6-3.05, 1.84, 1.46 and 1.22 δ; MS (EI) 200, 144, 127, 99, 70 and 57.

Workup

  1. customfor 16 hr
  2. customat 20-25°
  3. filtrationThe mixture is filtered
  4. washthe solids washed successively with ethanol, methylene chloride and methanol
  5. concentrationThe combined filtrates are concentrated
  6. additiondiluted with methylene chloride
  7. filtrationfiltered
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-ed88e93753f547978799453602a54fb1
Source dataset
uspto-grants-1999_08
Patent number
US05935970

Reaction notes

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