2-imidazolidin-2-ylidene-1-phenylethanone

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 20 g (0.105 mole) of triethyloxonium-tetrafluoroborate is dissolved in 200 ml of methylene chloride. To the solution is added 18.8 g (0.1 mole) of crystalline 2-(2-imidazolidinylidene)-acetophenone [m.p. 211°-212°, see J. Klosa, Arch.Pharmaz. 286, 397 (1953)]. After the slightly exothermic reaction has subsided, the reaction mixture, a clear yellow solution, is stirred for 16 hours at room temperature; it is subsequently concentrated to dryness in the rotary evaporator; and the crystallising residue is suspended in 300 ml of ethyl acetate. The suspension is cooled to 5°, and the crystals are filtered off with suction to obtain 2-(2-ethoxy-2-phenyl-ethenyl)-2-imidazoline-tetrafluoroborate, m.p. 151°-152°. After drying at 60° in vacuo, the product is further employed without additional purification. After the slightly exothermic reaction it is subsequently concentrated to dryness in the rotary evaporator The suspension is cooled to 5° the crystals are filtered off with suction

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 20 g (0.105 mole) of triethyloxonium-tetrafluoroborate is dissolved in 200 ml of methylene chloride. To the solution is added 18.8 g (0.1 mole) of crystalline 2-(2-imidazolidinylidene)-acetophenone [m.p. 211°-212°, see J. Klosa, Arch.Pharmaz. 286, 397 (1953)]. After the slightly exothermic reaction has subsided, the reaction mixture, a clear yellow solution, is stirred for 16 hours at room temperature; it is subsequently concentrated to dryness in the rotary evaporator; and the crystallising residue is suspended in 300 ml of ethyl acetate. The suspension is cooled to 5°, and the crystals are filtered off with suction to obtain 2-(2-ethoxy-2-phenyl-ethenyl)-2-imidazoline-tetrafluoroborate, m.p. 151°-152°. After drying at 60° in vacuo, the product is further employed without additional purification. After the slightly exothermic reaction it is subsequently concentrated to dryness in the rotary evaporator The suspension is cooled to 5° the crystals are filtered off with suction

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 20 g (0.105 mole) of triethyloxonium-tetrafluoroborate is dissolved in 200 ml of methylene chloride. To the solution is added 18.8 g (0.1 mole) of crystalline 2-(2--imidazolidinylidene)-acetophenone [m.p. 211°-212°, see J. Klosa, Arch. Pharmaz. 286, 397 (1953)]. After the slightly exothermic reaction has subsided, the reaction mixture, a clear yellow solution, is stirred for 16 hours at room temperature; it is subsequently concentrated to dryness in the rotary evaporator; and the crystallising residue is suspended in 300 ml of ethyl acetate. The suspension is cooled to 5°, and the crystals are filtered off with suction to obtain 2-(2-ethoxy-2-phenyl-ethenyl)-2-imidazoline-tetrafluoroborate, m.p. 151°-152°. After drying at 60° in vacuo, the product is further employed without additional purification. After the slightly exothermic reaction it is subsequently concentrated to dryness in the rotary evaporator The suspension is cooled to 5° the crystals are filtered off with suction

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 20 g (0.105 mole) of triethyloxonium-tetrafluoroborate is dissolved in 200 ml of methylene chloride. To the solution is added 18.8 g (0.1 mole) of crystalline 2-(2-imidazolidinylidene)-acetophenone [m.p. 211°-212°, see J. Klosa, Arch.Pharmaz. 286, 397 (1953)]. After the slightly exothermic reaction has subsided, the reaction mixture, a clear yellow solution, is stirred for 16 hours at room temperature; it is subsequently concentrated to dryness in the rotary evaporator; and the crystallising residue is suspended in 300 ml of ethyl acetate. The suspension is cooled to 5°, and the crystals are filtered off with suction to obtain 2-(2-ethoxy-2-phenyl-ethenyl)-2-imidazoline-tetrafluoroborate, m.p. 151°-152°. After drying at 60° in vacuo, the product is further employed without additional purification. After the slightly exothermic reaction it is subsequently concentrated to dryness in the rotary evaporator The suspension is cooled to 5° the crystals are filtered off with suction