تفاعل #11322

معادلة التفاعل

3,6-dichloro-4-cyclobutylpyridazine

benzoic hydrazide

triethylamine hydrochloride

→

title compound

المردود 34.0%

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

المردود 34.0%

المذيبات

p-xylene

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةheated
2. 2
   درجة الحرارةat reflux under a stream of nitrogen for 24 hours
3. 3
   درجة الحرارةUpon cooling the volatiles
4. 4
   أخرىwere removed in vacuo
5. 5
   أخرىThe residue was partitioned between dichloromethane and water
6. 6
   workup.ADDITIONThe aqueous was basified by the addition of solid potassium carbonate
7. 7
   أخرىSome dark insoluble material was removed by filtration at this stage
8. 8
   استخلاصThe aqueous phase was further extracted with dichloromethane (×2)
9. 9
   تجفيفThe combined extracts were dried (MgSO4)
10. 10
    ترشيحfiltered
11. 11
    أخرىevaporated
12. 12
    أخرىThe residue was purified by chromatography on silica gel eluting with 5%→10%→25% ethyl acetate/dichloromethane

الإجراء التجريبي

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]+.

المصدر