反応 #11322

反応方程式

3,6-dichloro-4-cyclobutylpyridazine

benzoic hydrazide

triethylamine hydrochloride

→

title compound

収率 34.0%

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

収率 34.0%

溶媒

p-xylene

反応条件

後処理

1. 1
   温度heated
2. 2
   温度at reflux under a stream of nitrogen for 24 hours
3. 3
   温度Upon cooling the volatiles
4. 4
   その他were removed in vacuo
5. 5
   その他The residue was partitioned between dichloromethane and water
6. 6
   workup.ADDITIONThe aqueous was basified by the addition of solid potassium carbonate
7. 7
   その他Some dark insoluble material was removed by filtration at this stage
8. 8
   抽出The aqueous phase was further extracted with dichloromethane (×2)
9. 9
   乾燥The combined extracts were dried (MgSO4)
10. 10
    ろ過filtered
11. 11
    その他evaporated
12. 12
    その他The residue was purified by chromatography on silica gel eluting with 5%→10%→25% ethyl acetate/dichloromethane

実験手順

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]+.

出典