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

HRID 3648

Reaction equation

HRID 3648 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 of which internal temperature was kept at 9° to 15° C. over 3 hours. Further, the temperature was kept at the same temperature for 2.5 hours. After that, the reaction liquid was poured into 3500 g of water with stirring. Thus obtained mixture was neutralized with an aqueous solution of sodium hydroxide. The precipitated crystalline solid was separated by filtration, washed with water and dried to obtain 338.7 g (1.89 moles) of N-tert-butyl-2-pyrazinecarboxamide. It had a melting point of 88° to 90° C. Further, from the filtrate 7.17 g (0.04 mole) of N-tert-butyl-2-pyrazine-carboxamide was further obtained by extraction thereof with toluene. The yield thereof was 91.9%.

Workup

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

Sources & evidence

ORD record
ord-b0a5f477af2d4178b1eacf13ac36441b
Source dataset
uspto-grants-1998_03
Patent number
US05734055

Linked notes

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