Hydrochloric Acid → 2-Chloro-3-(piperazin-1-yl)pyrazine

HRID 553476Notes

Reaction equation

HRID 553476 reaction equation
C(OC([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[C:19]([Cl:20])=[N:18][CH:17]=[CH:16][N:15]=2)[CH2:10][CH2:9]1)=O)(C)(C)C.Cl.[OH-].[Na+]>O1CCOCC1.C(Cl)Cl>[Cl:20][C:19]1[C:14]([N:11]2[CH2:10][CH2:9][NH:8][CH2:13][CH2:12]2)=[N:15][CH:16]=[CH:17][N:18]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 11150691Tert-butyl 4-(3-chloropyrazin-2-yl)piperazine-1-carboxylate

Product 1

HCID 140864382-Chloro-3-(piperazin-1-yl)pyrazine

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 312751,4-DioxaneSolvent2×

Procedure

To a solution of 3′-chloro-2,3,5,6-tetrahydro-[1,2′]bipyrazinyl-4-carboxylic acid t-butyl ester (10 g, 33.4 mmol, 1 eq) in 1,4-dioxane (160 mL) add a 4 M solution of hydrochloric acid in 1,4-dioxane (80 mL, 0.3 mol, 10 eq) and stir under nitrogen at room temperature overnight. Dilute with DCM (600 mL) then basify with 50% aqueous sodium hydroxide. Add water (100 mL), separate the layers and extract the aqueous twice with DCM (200 mL). Combine the organic extracts, wash with saturated aqueous sodium chloride, dry (magnesium sulfate), filter, and concentrate to give 3′-chloro-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl as a viscous oil which solidifies on standing (6.39 g, 96%). MS (ES): m/z=199.1, 201.1 [M+H]+.

Workup

  1. customAdd water (100 mL), separate the layers
  2. extractionextract the aqueous twice with DCM (200 mL)
  3. washCombine the organic extracts, wash with saturated aqueous sodium chloride
  4. dry with materialdry (magnesium sulfate)
  5. filtrationfilter
  6. concentrationconcentrate

Sources & evidence

ORD record
ord-68a003f9a7ff4b5aa37e5bdd177b66df
Source dataset
uspto-grants-2011_11
Patent number
US08048884B2

Reaction notes

Loading…