Acetic Acid → N2-cyclopropyl-N1-methyl-N1-phenylpropane-1,2-diamine

Participants

Reaction Conditions

Reaction Steps

To a cooled solution of 2.52 g (44 mmol) of cyclopropylamine and 3.3 g (55 mmol) of acetic acid, together with 10 g of 3 Å molecular sieves, in 100 ml of methanol, are added 3.6 g (22 mmol) of 1-[methyl(phenyl)amino]propan-2-one. The reaction mixture is stirred for 2.5 hrs at reflux. The reaction mixture is then cooled to 0° C. and 2.07 g (33 mmol) of sodium cyanoborohydride are slowly added and the reaction mixture is further stirred for 2 hrs at reflux. The cooled reaction mixture is then filtered over a cake of diatomaceous earth. The cake is washed twice by 80 ml of methanol and the combined methanolic extracts are concentrated under vacuum. 100 ml of water are then added to the residue and the pH is adjusted to 10 with a 0.5 N solution of sodium hydroxyde. The watery layer is extracted three times with ethyl acetate (3×50 ml). The combined organic layers are washed twice by brine and are filtered over a phase separator filter to yield after concentration 9.2 g of a yellow oil. Column chromatography (gradient heptane/ethyl acetate) yielded 2.5 g (50% yield) of N2-cyclopropyl-N1-methyl-N1-phenylpropane-1,2-diamine as a brown oil (M+H=205).

Provenance & Evidence