Sulfuric Acid → 3-Chloro-2-cyanopyrazine 1-oxide

HRID 1003395

Reaction equation

HRID 1003395 reaction equation
[Cl:1][C:2]1[C:7]([C:8]#[N:9])=[N:6][CH:5]=[CH:4][N:3]=1.[OH:10]S(O)(=O)=O>>[Cl:1][C:2]1[C:7]([C:8]#[N:9])=[N+:6]([O-:10])[CH:5]=[CH:4][N:3]=1

Participants

3

Reactant 2

HCID 1118Sulfuric AcidHCID 2924653-Chloropyrazine-2-carbonitrile

Product 1

HCID 107969923-Chloro-2-cyanopyrazine 1-oxideYield 36%

Conditions

Temperature
0 °C

Procedure

2-Chloro-3-cyano-pyrazine (5.00 g, 35.94 mmol) was dissolved in 35 ml concentrated H2SO4 under nitrogen and cooled to 0° C. To this was added 11.65 g (43.95 mmol) K2S2O8 portionwise. The flask was fitted with a CaCl2 drying tube, the reaction mixture allowed to warm to rt and stir for 24 h. After partitioning between CHCl3 and ice water, the separated aqueous phase was extracted with CHCl3. The combined organics were washed with water, saturated NaHCO3, brine and dried over MgSO4. Concentration gave 2.01 g (36%) of the title compound as an off-white solid. 1H NMR (300 MHz, CDCl3) δ 8.12 (d, 1H), 8.38 (d, 1H). MS (DCI/NH3) m/e 173 (M+NH4)+.

Workup

  1. customThe flask was fitted with a CaCl2 drying tube
  2. temperatureto warm to rt
  3. customAfter partitioning between CHCl3 and ice water
  4. extractionthe separated aqueous phase was extracted with CHCl3
  5. washThe combined organics were washed with water, saturated NaHCO3, brine
  6. dry with materialdried over MgSO4
  7. concentrationConcentration

Sources & evidence

ORD record
ord-a2e757f1d316492ebd44e0bcd1cc546b
Source dataset
uspto-grants-2000_04
Patent number
US06046207

Linked notes

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