Pyridine → (R)-4-Chlorocarbonyl-3-ethyl-piperazine-1-carboxylic acid tert-butyl ester

HRID 1794136Notes

Reaction equation

HRID 1794136 reaction equation
[Cl:1][C:2]([O:5]C(=O)OC(Cl)(Cl)Cl)(Cl)Cl.[C:13]([O:17][C:18]([N:20]1[CH2:25][CH2:24][NH:23][C@H:22]([CH2:26][CH3:27])[CH2:21]1)=[O:19])([CH3:16])([CH3:15])[CH3:14].N1C=CC=CC=1>ClCCl>[C:13]([O:17][C:18]([N:20]1[CH2:25][CH2:24][N:23]([C:2]([Cl:1])=[O:5])[C@H:22]([CH2:26][CH3:27])[CH2:21]1)=[O:19])([CH3:16])([CH3:15])[CH3:14]

Participants

5

Reactant 3

HCID 1049PyridineHCID 94429TriphosgeneHCID 24820337(R)-1-Boc-3-Ethylpiperazine

Product 1

HCID 86586001(R)-4-Chlorocarbonyl-3-ethyl-piperazine-1-carboxylic acid tert-butyl esterYield 262.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

Bis-(trichloromethyl)-carbonate (13.9 g, 47 mM) was dissolved in dichloromethane (500 mL) and cooled to 0° C. A mixture of (R)-3-ethyl-piperazine-1-carboxylic acid tert-butyl ester (26.5 g; 0.124 M) and pyridine (10.9 mL, 0.136 M) in dichloromethane (150 mL) was added dropwise with stirring (0–3° C.). Stirring was continued for another ½ h at room temperature. The mixture was washed with water and brine, the water phases were extracted with dichloromethane, organic phases were pooled, dried with Na2SO4 and evaporated to yield a brown oil (34 g, 99%) which crystallized upon standing; MS (EI): 276.2 (M)+.

Workup

  1. additionwas added dropwise
  2. stirringStirring
  3. washThe mixture was washed with water and brine
  4. extractionthe water phases were extracted with dichloromethane, organic phases
  5. dry with materialdried with Na2SO4
  6. customevaporated

Sources & evidence

ORD record
ord-5159be1b9b1c4d23b8b8a21749887f32
Source dataset
uspto-grants-2006_04
Patent number
US07022707B2

Reaction notes

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