Reacción #587300

Ecuación de reacción

1-(4-bromo-3-fluorophenyl)-2,2-diethoxyethanone

aminoguanidine bicarbonate

potassium hydroxide

→

desired product

6-(4-Bromo-3-fluorophenyl)-1,2,4-triazin-3-amine

Disolventes

ethanol

water

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawas refluxed overnight
2. 2
   OtroThe solvent was evaporated under reduced pressure
3. 3
   Lavadothe residue was washed with acetonitrile
4. 4
   Filtraciónfiltered
5. 5
   ConcentraciónThe filtrate was concentrated under reduced pressure
6. 6
   workup.DISSOLUTIONThe residue was dissolved in dichloromethane (100 mL)
7. 7
   Lavadowashed with water, brine
8. 8
   Concentraciónconcentrated under reduced pressure
9. 9
   workup.DISSOLUTIONThe residue was dissolved in ethanol (50 mL)
10. 10
    workup.ADDITIONTo the solution was added 0.2N hydrochloric acid (50 mL)
11. 11
    Temperaturacooled with an ice-water bath
12. 12
    OtroThe precipitate that formed
13. 13
    Filtraciónwas collected by filtration
14. 14
    Lavadowashed with isopropanol

Procedimiento

A mixture of 1-(4-bromo-3-fluorophenyl)-2,2-diethoxyethanone (15.2 g, 50 mmol), aminoguanidine bicarbonate (10.2 g, 75 mmol) and potassium hydroxide (6.6 g, 100 mmol) in ethanol (200 mL) and water (4 mL) was refluxed overnight. The solvent was evaporated under reduced pressure and the residue was washed with acetonitrile and filtered. The filtrate was concentrated under reduced pressure. The residue was dissolved in dichloromethane (100 mL), washed with water, brine, and concentrated under reduced pressure. The residue was dissolved in ethanol (50 mL). To the solution was added 0.2N hydrochloric acid (50 mL). The resultant mixture was heated to 110° C. for 8 h, and cooled with an ice-water bath. The precipitate that formed was collected by filtration and washed with isopropanol to give the desired product. (5.5 g, 41%) LCMS: (M+H)=286.8/288.8. 1H-NMR (400 MHz, CDCl3): 8.60 (s, 1H), 7.79 (dd, J=8.6, 2.0 Hz, 1H), 7.68 (dd, J=8.3, 7.0 Hz, 1H), 7.61 (dd, J=8.3, 2.0 Hz, 1H), 5.43 (s, 2H).

Fuente