Réaction #2028916

Équation de réaction

4,4′-difluorobenzil

trans-1,2-cyclohexanediamine

→

2,3-bis(4-fluorophenyl)-4a,5,6,7,8,8a-hexahydroquinoxaline

Rendement 94.0%

Solvants

ethanol

Conditions de réaction

Traitement

1. 1
   Températurethe mixed solution was refluxed under a nitrogen atmosphere for 3 hours
2. 2
   AutreBy leaving a the refluxed solution
3. 3
   Filtrationby filtration

Mode opératoire

First, 12.07 g of 4,4′-difluorobenzil (manufactured by Tokyo Kasei Kogyo Co., Ltd) was mixed with 5.60 g of trans-1,2-cyclohexanediamine (manufactured by Kanto Kasei Co., Ltd) by using 300 mL of ethanol as a solvent, and then the mixed solution was refluxed under a nitrogen atmosphere for 3 hours. By leaving a the refluxed solution to be cooled to a room temperature and taking out a deposited crystal by filtration, 2,3-bis(4-fluorophenyl)-4a,5,6,7,8,8a-hexahydroquinoxaline was obtained (light yellow plate-like crystal, yield: 94%). Subsequently, 6.90 g of 2,3-bis(4-fluorophenyl)-4a,5,6,7,8,8a-hexahydroquinoxaline which was obtained in the above step was mixed with 6.90 g of iron chloride (III) using 150 mL of ethanol as a solvent to gently stir with heat for 3 hours at 50° C. After the stirring, a deposition was caused by adding water to the stirred solution. A deposit was taken out by filtering and was washed with ethanol. Then, by recrystallizing the deposit with ethanol, a ligand 2,3-bis(4-fluorophenyl)-5,6,7,8-tetrahydroquinoxaline (abbreviation: HfdpqtH) was obtained (milky white powder, yield: 68%). Synthesis scheme of Step 1 (e-1) is shown next.

Source