Dichloromethane → 3,5-Dibromo-2-chloropyrazine

HRID 57935

Reaction equation

HRID 57935 reaction equation
[Br:1][C:2]1[C:3](N)=[N:4][CH:5]=[C:6]([Br:8])[N:7]=1.N(OC(C)(C)C)=O.[Cl:17]CCl>[Ti](Cl)(Cl)(Cl)Cl>[Br:1][C:2]1[C:3]([Cl:17])=[N:4][CH:5]=[C:6]([Br:8])[N:7]=1

Participants

5

Reactant 3

HCID 6344Dichloromethane2×HCID 10906Tert-Butyl nitriteHCID 6200042-Amino-3,5-dibromopyrazine

Product 1

HCID 533503583,5-Dibromo-2-chloropyrazine

Reagents, catalysts & solvents 1

HCID 24193Titanium TetrachlorideCatalyst

Procedure

To a solution of 3,5-dibromopyrazin-2-amine (1.00 g, 3.95 mmol) in dichloromethane 6.0 ml at 0° C. was added titanium tetrachloride (1 mol/l) in dichloromethane (3.95 mL, 3.95 mmol) then tert-butyl nitrite (1.05 mL, 7.91 mmol) was added dropwise. The reaction was warmed to RT then 1 more equivalent of TiCL4 was added and stirred for 1 h. The reaction was quenched with water and extracted with DCM. The organic layers was dried with sodium sulfate, filtered, and concentrated in vacuum. The crude product was carried to next step. MS (ESI) m/z: 272.2.

Workup

  1. addition1 more equivalent of TiCL4 was added
  2. customThe reaction was quenched with water
  3. extractionextracted with DCM
  4. dry with materialThe organic layers was dried with sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuum

Sources & evidence

ORD record
ord-7aed7c16ee7542eb8f1c3f5607bec920
Source dataset
uspto-grants-2016_09
Patent number
US09434725B2

Linked notes

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