Réaction #3744

Équation de réaction

tert-butyl alcohol

sulfuric acid

2-cyanopyrazine

sodium hydroxide

→

N-tert-butyl-2-pyrazinecarboxamide

Solvants

water

Conditions de réaction

Traitement

1. 1
   Autreat 40° C. or less
2. 2
   workup.WAITFurther, the temperature was kept at the same temperature for 2.5 hours
3. 3
   AutreAfter that, the reaction liquid
4. 4
   workup.STIRRINGwith stirring
5. 5
   AutreThe precipitated crystalline solid was separated by filtration
6. 6
   Lavagewashed with water
7. 7
   Autredried

Mode opératoire

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%.

Source