Isopropyl iodide → (2R)-1-(tert-butoxycarbonyl)-4-isopropylpiperazine-2-carboxylic acid

HRID 549926Notes

Reaction equation

HRID 549926 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][C@@H:9]1[C:14]([OH:16])=[O:15])=[O:7])([CH3:4])([CH3:3])[CH3:2].C([O-])([O-])=O.[Na+].[Na+].[CH:23](I)([CH3:25])[CH3:24]>CCO>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([CH:23]([CH3:25])[CH3:24])[CH2:10][C@@H:9]1[C:14]([OH:16])=[O:15])=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 3

HCID 6362Isopropyl iodideHCID 10340Sodium CarbonateHCID 24820285(2R)-1-(tert-Butoxycarbonyl)piperazine-2-carboxylic acid

Product 1

HCID 51440433(2R)-1-(tert-butoxycarbonyl)-4-isopropylpiperazine-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To (2R)-1-(tert-butoxycarbonyl)piperazine-2-carboxylic acid (4.5 g) and Na2CO3 (8.32 g) was added dry EtOH (135 ml) and isopropyl iodide (2.16 ml) and the mixture heated at reflux for 18 hours under argon. The solvent was then removed under reduced pressure, 5% MeOH/DCM (50 ml) added, the mixture stirred for 1 hour in a stoppered flask, filtered and washed through with DCM (2×10 ml). The filtrate was applied directly to a 120 g-silica Redisep® cartridge and purified using 10-70% MeOH/DCM. After evaporation, the product was isolated as a white foam (4.50 g), which was used without further purification.

Workup

  1. temperaturethe mixture heated
  2. temperatureat reflux for 18 hours under argon
  3. customThe solvent was then removed under reduced pressure, 5% MeOH/DCM (50 ml)
  4. additionadded
  5. filtrationfiltered
  6. washwashed through with DCM (2×10 ml)
  7. custompurified
  8. customAfter evaporation

Sources & evidence

ORD record
ord-745b14d1a35b4bd4a6958f25120c87b3
Source dataset
uspto-grants-2011_05
Patent number
US07943768B2

Reaction notes

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