Hydrochloric Acid → 1,4-Bis(benzyloxycarbonyl)piperazine-2-carboxylic acid

HRID 912948Notes

Reaction equation

HRID 912948 reaction equation
Cl[C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3].Cl.Cl.[NH:14]1[CH2:19][CH2:18][NH:17][CH2:16][CH:15]1[C:20]([OH:22])=[O:21].[C:23]([O-:26])([O-])=[O:24].[Na+].[Na+].Cl>O>[CH2:5]([O:4][C:2]([N:14]1[CH2:19][CH2:18][N:17]([C:23]([O:26][CH2:5][C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=2)=[O:24])[CH2:16][CH:15]1[C:20]([OH:22])=[O:21])=[O:3])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1

Participants

6

Conditions

Temperature
0 °C

Procedure

Benzyl chloroformate (3.1 mL, 22 mmol, Aldrich) was added dropwise over a period of 5 min to a mixture of piperazine-2-carboxylic acid dihydrochloride (2.03 g, 10 mmol, Aldrich) and Na2CO3 (4.24 g, 40 mmol) in water (10 mL) with stirring at 0° C. The mixture was stirred at 0° C. for 1 h, 2N HCl (10 mL) was added and the mixture was extracted with EtOAc (3×40 mL). The combined organic extracts were washed with water (10 mL) and brine (20 mL), dried over Na2SO4, and filtered. The filtrate was evaporated in vacuo to give the title compound as a gum, which was used for the next step without additional purification. MS (ESI, pos. ion) m/e: 399 (M+1).

Workup

  1. stirringThe mixture was stirred at 0° C. for 1 h
  2. extractionthe mixture was extracted with EtOAc (3×40 mL)
  3. washThe combined organic extracts were washed with water (10 mL) and brine (20 mL)
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. customThe filtrate was evaporated in vacuo

Sources & evidence

ORD record
ord-eae1e85ea032409a9b799d96da67f34d
Source dataset
uspto-grants-2011_09
Patent number
US08026241B2

Reaction notes

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