反应详情

380 mg (2 mmol) of triethyloxonium tetrafluoroborate are dissolved in 15 ml of methylene chloride. 326 mg (2 mmol) of p-dimethylaminoacetophenone are added thereto at -15°. After 5 minutes there are added thereto at the same temperature 162 mg (1 mmol) of 1,3-diamino-2-ethyl-imidazolium chloride and the mixture is stirred at -10° for 1 hour and at 0° for 2 hours. After the addition of a small amount of methanol the mixture is evaporated and the residue is placed on a column loaded with 10 g of silica gel. The product is eluted with chloroform/methanol (87:13 parts by weight) and crystallized using ether. The crystallizate is dissolved in 80 ml of water, placed on a column loaded with ion exchanger Amberlite IRA 400 (chloride) and elution is carried out with water. The eluate is evaporated and the residue is crystallized from ethanol/water. There is obtained 3-amino-1-[[p-(dimethylamino)-α-methylbenzylidene]amino]-2 -ethylimidazolium chloride of melting point 223°-225°.

1. customat -15°
2. additionAfter 5 minutes there are added
3. customis evaporated
4. washThe product is eluted with chloroform/methanol (87:13 parts by weight)
5. customcrystallized
6. dissolutionThe crystallizate is dissolved in 80 ml of water
7. washloaded with ion exchanger Amberlite IRA 400 (chloride) and elution
8. customThe eluate is evaporated
9. customthe residue is crystallized from ethanol/water