Reaktion #1269217

Reaktionsgleichung

acetone

Oxalyl chloride

2,2,3,3-tetramethylcyclopropane carboxylic acid

1,2-dimethylimidazole

→

Intermediate 25

Ausbeute 84.5%

2.3-dimethyl-1-[(2,2,3,3-tetramethylcyclopropyl)carbonyl]-1H-imidazol-3-ium chloride

Ausbeute 84.5%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe solution was then heated
2. 2
   Temperaturto reflux for 30 min
3. 3
   Temperaturmaintaining the internal temperature around 5° C
4. 4
   TemperaturThe resulting suspension was then warmed to 18° C.
5. 5
   Temperaturmaintaining the internal temperature around 18° C
6. 6
   TemperaturThe slurry was cooled to 5° C. over 30 minutes
7. 7
   Filtrationfiltered
8. 8
   FiltrationThe product was colected by filtration
9. 9
   Waschenwashed with acetone:dichloromethane (3:1, 3×1.2 L)
10. 10
    Sonstigesucked dry
11. 11
    Sonstigedried in a vacuum oven at 25-30° C. for 10 hours

Vorschrift

Oxalyl chloride (360 ml, 4.1 mol) was added over 65 min to a stirred solution of 2,2,3,3-tetramethylcyclopropane carboxylic acid (600 g, 4.2 mol) in dichloromethane (3.6 L) at 34° C. The solution was then heated to reflux for 30 min and then cooled to 5° C. A solution of 1,2-dimethylimidazole (490 g, 5.1 mol) in dichloromethane (1.2 L) was added over 45 min maintaining the internal temperature around 5° C. The resulting suspension was then warmed to 18° C. and acetone (4.8 L) was added over 45 minutes maintaining the internal temperature around 18° C. The slurry was cooled to 5° C. over 30 minutes, stirred at 5° C. for 30 minutes and then filtered. The product was colected by filtration, washed with acetone:dichloromethane (3:1, 3×1.2 L), sucked dry and then dried in a vacuum oven at 25-30° C. for 10 hours to give Intermediate 25 as a white solid (890 g) 1H nmr: δH (CDCl3, 400 MHz) 8.45 (d, J 2.4 Hz, 1H), 8.11 (d, J 2.4 Hz, 1H), 4.21 (s, 3H), 2.96 (s, 3H), 2.21 (s, 1H), 1.43 (s, 6H), 1.33 (s, 6H).

Quelle