Réaction #1168

Équation de réaction

2-(4-t-butoxycarbonylaminophenyl)-3-oxobutyronitrile

ethanol

2,2-diethoxyethylhydrazine

hydrogen chloride

→

title compound

7-(4-Aminophenyl)-6-methyl-1H-imidazo[1,2-b]-pyrazole hydrochloride

Solvants

ethyl acetate

dioxane

Conditions de réaction

Traitement

1. 1
   Températurewas heated
2. 2
   Températureunder reflux for 2 hours
3. 3
   Températurethe whole mixture was heated
4. 4
   Températureunder reflux for a further 30 minutes
5. 5
   TempératureAfter the mixture had been cooled
6. 6
   Autreto precipitate crystals
7. 7
   FiltrationThese crystals were collected by filtration
8. 8
   Autrerecrystallized from ethanol

Mode opératoire

A mixture of 2.5 g of 2-(4-t-butoxycarbonylaminophenyl)-3-oxobutyronitrile, 20 ml of ethanol and 1.4 g of 2,2-diethoxyethylhydrazine was heated under reflux for 2 hours. 20 ml of 4N hydrogen chloride in dioxane were added, and then the whole mixture was heated under reflux for a further 30 minutes. After the mixture had been cooled, ethyl acetate was added to precipitate crystals. These crystals were collected by filtration and recrystallized from ethanol to give 1.4 g of the title compound as pale brown plates melting at 180°-190° C.

Source