Hydrazine → 2-(1H-Pyrazol-5-yl)pyrazine

HRID 558040Notes

Reaction equation

HRID 558040 reaction equation
[C:1]([C:4]1[CH:9]=[N:8][CH:7]=[CH:6][N:5]=1)(=O)[CH3:2].COC(OC)[N:13]([CH3:15])C.[NH2:18]N>C(O)C>[NH:18]1[C:1]([C:4]2[CH:9]=[N:8][CH:7]=[CH:6][N:5]=2)=[CH:2][CH:15]=[N:13]1

Participants

5

Reactant 3

HCID 9321HydrazineHCID 30914AcetylpyrazineHCID 78373Dimethylformamide dimethyl acetal

Product 1

HCID 158655482-(1H-Pyrazol-5-yl)pyrazineYield 94%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

2-Acetylpyrazine (10 mmol, 1.22 g) is reacted with N,N-Dimethylformamide dimethyl acetal (15 mmol, 1.99 ml) without any solvent at 100° C. for 10 hrs. Extraction with methylene chloride and water is carried out and the organic layer is concentrated to obtain solids. The yield is 94%. The obtained product is dissolved in ethanol and then added with hydrazine (23.5 mmol, 1.14 ml). The reaction is carried out for 3 hrs at 90° C. The reaction solution is concentrated and extracted by methylene chloride and water. The product is rinsed by n-hexane and some ethanol. The product pzp is thus obtained and the yield is 83%. 1H NMR (400 MHz, CDCl3): δ 9.11 (s, 1 H), 8.55 (s, 1 H), 8.50 (d, 1 H, J=2.8 Hz), 7.69 (d, 1 H, J=1.6 Hz), 6.93 (d, 1 H, J=2.0 Hz).

Workup

  1. extractionExtraction with methylene chloride and water
  2. concentrationthe organic layer is concentrated
  3. customto obtain solids
  4. concentrationThe reaction solution is concentrated
  5. extractionextracted by methylene chloride and water
  6. washThe product is rinsed by n-hexane
  7. customThe product pzp is thus obtained

Sources & evidence

ORD record
ord-cc74fb6ef0ff47409bce01522062636a
Source dataset
uspto-grants-2011_11
Patent number
US08062767B2

Reaction notes

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