Reaktion #11322

Reaktionsgleichung

3,6-dichloro-4-cyclobutylpyridazine

benzoic hydrazide

triethylamine hydrochloride

→

title compound

Ausbeute 34.0%

6-Chloro-7-cyclobutyl-3-phenyl-1,2,4-triazolo[4,3-b]pyridazine

Ausbeute 34.0%

Lösungsmittel

p-xylene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated
2. 2
   Temperaturat reflux under a stream of nitrogen for 24 hours
3. 3
   TemperaturUpon cooling the volatiles
4. 4
   Sonstigewere removed in vacuo
5. 5
   SonstigeThe residue was partitioned between dichloromethane and water
6. 6
   workup.ADDITIONThe aqueous was basified by the addition of solid potassium carbonate
7. 7
   SonstigeSome dark insoluble material was removed by filtration at this stage
8. 8
   ExtraktionThe aqueous phase was further extracted with dichloromethane (×2)
9. 9
   TrocknenThe combined extracts were dried (MgSO4)
10. 10
    Filtrationfiltered
11. 11
    Sonstigeevaporated
12. 12
    SonstigeThe residue was purified by chromatography on silica gel eluting with 5%→10%→25% ethyl acetate/dichloromethane

Vorschrift

A mixture of 3,6-dichloro-4-cyclobutylpyridazine from above (55.7 g, 0.27 mol), benzoic hydrazide (41.1 g, 0.30 mol) and triethylamine hydrochloride (41.5 g, 0.30 mol) in p-xylene (0.4 l) was stirred and heated at reflux under a stream of nitrogen for 24 hours. Upon cooling the volatiles were removed in vacuo. The residue was partitioned between dichloromethane and water. The aqueous was basified by the addition of solid potassium carbonate. Some dark insoluble material was removed by filtration at this stage. The aqueous phase was further extracted with dichloromethane (×2). The combined extracts were dried (MgSO4), filtered and evaporated. The residue was purified by chromatography on silica gel eluting with 5%→10%→25% ethyl acetate/dichloromethane to give the title compound, (26.4 g, 34%) as an off-white solid. Data for the title compound: 1H NMR (360 MHz, CDCl3) δ 1.90–2.00 (1H, m), 2.12–2.28 (3H, m), 2.48–2.57 (2H, m), 3.69–3.78 (1H,m), 7.49–7.59 (3H, m), 7.97 (1H, s), 8.45–8.48 (2H, m); MS (ES+) m/e 285 [MH]+, 287 [MH]+.

Quelle