If I'm not mistaken, a Mannich on a propiophenone will give the wrong cathinone isomer, i.e. that with the amine on the terminal carbon, which is why we're stuck with the bromoketone intermediate
. It's such a shame that lovely smelling propiophenones have to be converted into such nasty lachrymators to get to the final product.
According to Beilstein, the nomenclature for 4-aminobutan-2-one is correct. For such a simple molecule it's quite difficult to synthesise, precursor wise; there are no references for the Mannich on acetone given. The best way seems to be starting from methyl vinyl ketone; react it with phthalimide in ethyl acetate in the presence of sodium methoxide. See
Chem.Abstr.; 57; 1962; 8555. The yield isn't given I'm afraid. The yield is given, however, for what looks like an extremely easy cleavage of the phthalimido group to give the HCl salt of 4-aminobutan-2-one; heat in aqueous HCl for 24 hours, yield 99%
. See
Monatsh.Chem.; 132; 2; 2001; 279 - 294 for the procedure, or a very similar one is given in
J.Med.Chem.; 28; 1; 1985; 9-12.My next point (and the real reason for making this post) is to ask Barium for more information on his t-butylamino and N,N-diisopropylamino cathinones. What were the ring substituents, and how long was the
alpha-alkyl chain? MPPH, a Pyrovalerone analogue with a hexanophenone chain, is active at around 20-50mg if I recall correctly. Best check with Nemo_Tenetur though..
It'd be interesting to hear if anyone has tried the larger N-substituents on the shorter chain propiophenones.