Reacción #63927

Ecuación de reacción

N-methyl-N-[3-(6-chloro-3-pyridazinyl)phenyl]acetamide

thiosemicarbazide

→

yellow crystals

Rendimiento 34.0%

N-Methyl-N-[3-(3-amino-1,2,4-triazolo[4,3-b]pyridazin-6-yl)phenyl]acetamide

Rendimiento 34.0%

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturaat reflux for 5.5 hours
2. 2
   OtroThe ethanol was removed in vacuo, 100 ml glacial acetic acid
3. 3
   workup.ADDITIONadded
4. 4
   Temperaturathe mixture was refluxed for 18 hours
5. 5
   OtroThe acetic acid was removed in vacuo
6. 6
   workup.ADDITIONthe yellow residue added to 300 ml water
7. 7
   Extracciónextracted with 100 ml portions of dichloromethane and dichloromethane-ethyl acetate
8. 8
   OtroThe combined extracts were dried
9. 9
   Otrothe solvent removed in vacuo
10. 10
    Otrothe product mixture chromatographed on silica gel
11. 11
    Otrorecrystalizing from ether-methanol-hexane

Procedimiento

A solution of 3.0 g N-methyl-N-[3-(6-chloro-3-pyridazinyl)phenyl]acetamide and 2.0 g thiosemicarbazide in 100 ml ethanol was heated at reflux for 5.5 hours. The ethanol was removed in vacuo, 100 ml glacial acetic acid added and the mixture was refluxed for 18 hours. The acetic acid was removed in vacuo and the yellow residue added to 300 ml water. This mixture was brought to pH~7 with aqueous sodium bicarbonate and extracted with 100 ml portions of dichloromethane and dichloromethane-ethyl acetate. The combined extracts were dried, the solvent removed in vacuo, and the product mixture chromatographed on silica gel using dichloromethane-methanol (95.5) as solvent. Recombining the pure fractions and recrystalizing from ether-methanol-hexane afforded 1.10 g yellow crystals, mp 206°-207° C.

Fuente