Acetic Acid → (3R)-3,4-dibenzylpiperazin-2-one

HRID 581201Notes

Reaction equation

HRID 581201 reaction equation
COC(=O)[C@H:4]([NH:12][CH2:13][CH2:14][NH:15][C:16]([O:18]C(C)(C)C)=O)[CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.[CH:24](=O)[C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1.C(O)(=O)C.C([BH3-])#N.[Na+]>CO>[CH2:5]([C@H:4]1[N:12]([CH2:24][C:25]2[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=2)[CH2:13][CH2:14][NH:15][C:16]1=[O:18])[C:6]1[CH:7]=[CH:8][CH:9]=[CH:10][CH:11]=1

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 240BenzaldehydeHCID 5003444Sodium cyanoborohydrideHCID 54571530(2R)-2-(2-(tert-butoxycarbonylamino)ethylamino)-3-phenylpropionic acid methyl ester

Product 1

HCID 53922812(3R)-3,4-dibenzylpiperazin-2-one

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

(3R)-3-Benzylpiperazin-2-one (4.1 g; 21.6 mmol, prepared as described in Example 1) was dissolved in methanol (40 ml). Benzaldehyde (2.3 g; 21.6 mmol) was added followed by 4 Å molsieves (2 g) and the mixture was stirred under an atmosphere of nitrogen for 1/2 h. Acetic acid (1.2 ml) was added and sodium cyanoborohydride (2.0 g; 32.4 mmol) was added portion wise during 20 minutes. The reaction mixture was stirred overnight and the filtered. From the filtrate the solvent was evaporated and the residue was dissolved into ethyl acetate (15 ml) and purified on silica gel using ethyl acetate as eluent. This afforded 2.6 g of (3R)-3,4-dibenzylpiperazin-2-one.

Workup

  1. stirringThe reaction mixture was stirred overnight
  2. customFrom the filtrate the solvent was evaporated
  3. dissolutionthe residue was dissolved into ethyl acetate (15 ml)
  4. custompurified on silica gel

Sources & evidence

ORD record
ord-1b78e464f93e474590a58c8ece1b6375
Source dataset
uspto-grants-1999_07
Patent number
US05919777

Reaction notes

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