Bicarbonate Ion → 1-[(2,3-Dichlorophenyl)carbonyl]-5-(ethyloxy)-1,2,3,6-tetrahydropyrazine

HRID 1889076Notes

Reaction equation

HRID 1889076 reaction equation
[Cl:1][C:2]1[C:7]([Cl:8])=[CH:6][CH:5]=[CH:4][C:3]=1[C:9]([N:11]1[CH2:16][CH2:15][NH:14][C:13](=[O:17])[CH2:12]1)=[O:10].F[B-](F)(F)F.[CH2:23]([O+](CC)CC)[CH3:24].C(=O)(O)[O-]>ClCCl>[Cl:1][C:2]1[C:7]([Cl:8])=[CH:6][CH:5]=[CH:4][C:3]=1[C:9]([N:11]1[CH2:12][C:13]([O:17][CH2:23][CH3:24])=[N:14][CH2:15][CH2:16]1)=[O:10]

Participants

5

Reactant 3

HCID 769Bicarbonate IonHCID 2723982Triethyloxonium tetrafluoroborateHCID 310960434-(2,3-Dichlorobenzoyl)piperazin-2-one2×

Product 1

HCID 665989011-[(2,3-Dichlorophenyl)carbonyl]-5-(ethyloxy)-1,2,3,6-tetrahydropyrazineYield 88.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a suspension of 4-[(2,3-dichlorophenyl)carbonyl]-2-piperazinone (1 g, 3.66 mmol, e.g. prepared as described in Intermediate 3) in dry Dichloromethane (DCM) (9.15 ml) was added triethyloxonium tetrafluoroborate (1.739 g, 9.15 mmol). The suspension turned shortly to a yellow solution and it was stirred at room temperature under argon. After 5 minutes the mixture was diluted with Dichloromethane (20 mL) and treated with ice (15 mL). The pH was adjusted to circa 7 with saturated bicarbonate solution, the phases were separated and the aqueous extracted with Dichloromethane (50 mL). The combined organics were washed with brine and dried over MgSO4. Evaporation gave 1-[(2,3-dichlorophenyl)carbonyl]-5-(ethyloxy)-1,2,3,6-tetrahydropyrazine (0.98 g) as an orange oil which was used without further purification.

Workup

  1. customthe phases were separated
  2. extractionthe aqueous extracted with Dichloromethane (50 mL)
  3. washThe combined organics were washed with brine
  4. dry with materialdried over MgSO4
  5. customEvaporation

Sources & evidence

ORD record
ord-d515732c2fd54ddd84ea13c1c94d6254
Source dataset
uspto-grants-2013_08
Patent number
US08501946B2

Reaction notes

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