Reacción #445982

ord-a3dd463c1e5344bd87c9eb7a5e887993

Disolventes

Condiciones de reacción

Condiciones detalladas
See reaction.notes.procedure_details.

Tratamiento posterior

  1. 1
    Otroas the reaction progresses
  2. 2
    Lavadothe mixture is washed twice with 20 ml of water each time
  3. 3
    Secadodried over sodium sulfate
  4. 4
    Filtraciónfiltered
  5. 5
    Otrothe solvent is evaporated
  6. 6
    Otrois purified by column chromatography over silica gel (diethyl ether/toluene: 5/3)
  7. 7
    OtroAfter the eluant mixture has been evaporated off
  8. 8
    Otroto crystallise
  9. 9
    Otrorecrystallised from diethyl ether/petroleum ether at 30°-50° C
  10. 10
    OtroLight-brown crystals are obtained
  11. 11
    Otroyield: 8.55 g (38 mmol) (=74.5% of the theoretical yield)

Procedimiento

10 g (51 mmol) of phenylguanidine hydrogen carbonate and 9.7 g (77 mmol) of 1-cyclopropyl-1,3-butanedione are heated at 110° C. for 6 hours with stirring, the evolution of carbon dioxide which occurs subsiding as the reaction progresses. After the dark brown emulsion has been cooled to room temperature, 50 ml of diethyl ether are added and the mixture is washed twice with 20 ml of water each time, dried over sodium sulfate and filtered, and the solvent is evaporated. The dark brown oil which remains (=13.1 g) is purified by column chromatography over silica gel (diethyl ether/toluene: 5/3). After the eluant mixture has been evaporated off, the brown oil is made to crystallise and recrystallised from diethyl ether/petroleum ether at 30°-50° C. Light-brown crystals are obtained. Melting point: 67°-69° C.; yield: 8.55 g (38 mmol) (=74.5% of the theoretical yield).

Fuente

DOI: 10.6084/m9.figshare.5104873.v1Patente: US04997941uspto-grants-1991_03