Reaktion #54310

Reaktionsgleichung

8-amino-5-hydroxy-3,4-dihydrocarbostyril

cyclohexylcarbonyl chloride

→

8-cyclohexylcarbonylamino-5-hydroxy-3,4-dihydrocarbostyril

Ausbeute 38.1%

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGby stirring at 50° C. for 30 minutes
2. 2
   FiltrationThe precipitated crystals were recovered by filtration
3. 3
   Waschenwashed with ethanol
4. 4
   Sonstigedried
5. 5
   workup.DISSOLUTIONdissolved in 200 ml of a 10% aqueous sodium hydroxide solution
6. 6
   workup.ADDITIONActivated carbon was added to the solution
7. 7
   workup.STIRRINGthe mixture was stirred
8. 8
   Filtrationfiltered
9. 9
   Filtrationthe precipitated crystals were recovered by filtration
10. 10
    Waschenwashed with water
11. 11
    Sonstigedried
12. 12
    SonstigeRecrystallization from methanol

Vorschrift

10.7 g of 8-amino-5-hydroxy-3,4-dihydrocarbostyril was dissolved in 100 ml of pyridine, and 10.0 g of cyclohexylcarbonyl chloride was added to the solution while vigorously stirring at room temperature followed by stirring at 50° C. for 30 minutes. The precipitated crystals were recovered by filtration, washed with ethanol, dried and dissolved in 200 ml of a 10% aqueous sodium hydroxide solution. Activated carbon was added to the solution, and the mixture was stirred and filtered. The filtrate was rendered acidic with hydrochloric acid under ice cooling, and the precipitated crystals were recovered by filtration, washed with water and dried. Recrystallization from methanol yielded 6.6 g of 8-cyclohexylcarbonylamino-5-hydroxy-3,4-dihydrocarbostyril as colorless amorphous crystals having a melting point of 304.2°-304.8° C.

Quelle