Sulfuric Acid → N-tert-butylpyrazine-2-carboxamide

HRID 3647

Reaction equation

HRID 3647 reaction equation
S(=O)(=O)(O)O.[C:6]([C:8]1[CH:13]=[N:12][CH:11]=[CH:10][N:9]=1)#[N:7].[C:14](O)([CH3:17])([CH3:16])[CH3:15].[OH-:19].[Na+]>O>[C:14]([NH:7][C:6]([C:8]1[CH:13]=[N:12][CH:11]=[CH:10][N:9]=1)=[O:19])([CH3:17])([CH3:16])[CH3:15]

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 6386tert-ButanolHCID 14798Sodium HydroxideHCID 73172Pyrazinecarbonitrile

Product 1

HCID 4462842N-tert-butylpyrazine-2-carboxamide

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To 1030 g of an 80% aqueous solution of sulfuric acid (8.40 moles of sulfuric acid), 220.5 g (2.10 moles) of 2-cyanopyrazine was added dropwise keeping the internal temperature at 40° C. or less with stirring. In succession, 187 g (2.52 moles) of tert-butyl alcohol was added dropwise to the mixture, keeping the internal temperature at 9° to 15° C., over 3 hours. Further, the temperature was kept at the same temperature for 2.5 hours. After the reaction, the reaction liquid was added to 3500 g of water with stirring. Thus obtained mixture was neutralized with an aqueous solution of sodium hydroxide. Precipitated crystalline solid was separated by filtration, washed with water and then dried to obtain 338.7 g (1.89 moles) of N-tert-butyl-2-pyrazine-carboxamide. It had a melting point of 88° to 90° C. Further, from the water layer, from which the intended product had been separated by filtration, 7.17 g (0.04 mole) of the intended product was further obtained by extraction thereof with toluene.

Workup

  1. customat 40° C. or less
  2. customat 9° to 15° C.
  3. waitFurther, the temperature was kept at the same temperature for 2.5 hours
  4. customAfter the reaction
  5. customthe reaction liquid
  6. stirringwith stirring
  7. customPrecipitated crystalline solid was separated by filtration
  8. washwashed with water
  9. customdried

Sources & evidence

ORD record
ord-a23e58160f8d42ea84086afccb55201f
Source dataset
uspto-grants-1998_03
Patent number
US05734055

Linked notes

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