Water → (4-Methoxybenzylidene)-(4-{[(4-methoxybenzylidene)amino]methyl}-phenyl)amine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

430 ml of toluene and 40 ml (349 mmol) of 99% pure 4-aminobenzylamine are introduced into a four-neck flask with mechanical paddle stirrer, water trap and reflux condenser. A two-phase mixture is obtained owing to the low solubility of the amine. 96 ml (775 mmol) of 98% pure anisaldehyde are added, and the mixture is heated with an oil bath heated to 140° C. In the heating-up phase, the reaction mixture starts to boil at around 80° C., and cloudy water/toluene azeotrope distills into the water trap. After about 30 min, the maximum internal temperature is 114° C., and only clear toluene now distills over. 12.5 ml of water (corresponding to about 100% of theory of the two equivalents of water) separate out. A TLC check (plate deactivated by previously standing in NEt3(triethylamine) vapor-saturated tank, ethyl acetate/n-heptane 1:1 plus 1% NEt3) indicates complete conversion of the 4-aminobenzylamine. The mixture is actively cooled to room temperature. A mixture of 800 ml of n-heptane and 200 ml of ethyl acetate is then run slowly in, during which, after addition of only about 200 ml, a pale yellow precipitate separates out spontaneously. The mixture is stirred for 1 h, and the precipitate is filtered off with suction and dried under HV. Yield: 105.6 g.

Herkunft & Nachweise