تفاعل #440277

معادلة التفاعل

2,6-difluorobenzaldehyde

3,5-heptanedione

2,6-difluorobenzaldehyde

acetic acid

→

title compound

المردود 30.7%

4-(2,6-Difluorobenzylidene)-3,5-heptanedione

المردود 30.7%

المذيبات

toluene

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةAfter cooling
2. 2
   ترشيحthe molecular sieves were filtered off
3. 3
   تركيزThe filtrate was concentrated under reduced pressure
4. 4
   أخرىThe residue was partitioned between dichloromethane and water
5. 5
   تجفيفThe organic phase was dried over anhydrous magnesium sulphate
6. 6
   ترشيحfiltered
7. 7
   تركيزconcentrated under reduced pressure
8. 8
   أخرىThe crude material was purified by flash chromatography on silica gel eluting with pentane:dichloromethane (4:1, by volume)

الإجراء التجريبي

A mixture of 3,5-heptanedione (1.36 ml, 10 mmol), 2,6-difluorobenzaldehyde (1.08 ml, 10 mmol), piperidine (20 μL, 0.2 mmol), glacial acetic acid (149 μL, 2.6 mmol), molecular sieves and toluene (7 ml) was heated at 70° C., under a nitrogen atmosphere for 3 hours. Further 2,6-difluorobenzaldehyde (540 μL, 5 mmol) was added and the resulting mixture was stirred at 70° C. for a further 7 hours. After cooling, the molecular sieves were filtered off. The filtrate was concentrated under reduced pressure. The residue was partitioned between dichloromethane and water. The organic phase was dried over anhydrous magnesium sulphate, filtered and concentrated under reduced pressure. The crude material was purified by flash chromatography on silica gel eluting with pentane:dichloromethane (4:1, by volume) and then with a solvent gradient of pentane:diethylether (20:1, by volume) gradually changing to pentane:diethylether (10:1, by volume) to afford the title compound (775 mg) as a colourless oil.

المصدر