The reaction you are referring to is a somewhat complex one, involving several different chemical processes. Here is a simplified explanation.
References :
Potassium ferricyanide [K. ferricyanide /
C12Fe2K7N12]
Sodium hydroxide [NaOH / HNaO]
Selegiline (
C13H17N)
Water (
H2O)
Ammonia [
NH3 /
H3N]
Amphetamine (
C9H13N)
Sodium borohydride [
NaBH4 /
BH4Na]
Sodium cyanoborohydride [
NaBH3CN/ CBNNa]
Methamphetamine (
C10H15N)
C12Fe2K7N12 is an oxidizer. When mixed with an alkaline solution of NaOH, the resulting mixture becomes even more reactive.
C13H17Nis a monoamine oxidase inhibitor (MAOI) that is often used in the treatment of Parkinson's disease. It's structure contains a phenyl ring and an amine group. When reacting all of these together, the oxidizer reacts with the amine group of
C13H17Ncausing it to lose a H atom and become an imine (
C13H16N2) (aka Schiff base).
C13H17N+
C12Fe2K7N12/NaOH →
C13H16N2 +
H2O
The imine reacts with the
C12Fe2K7N12 and NaOH to undergo a process called oxidative deamination. In this process, the imine loses an amine group, which is converted to
NH3.
C13H16N2 + C12Fe2K7N12/NaOH →
C12H15NO+
NH3
The resulting compound contains a phenyl ring and a ketone group (
C12H15NO). At this point, the reaction can take one of two paths. The ketone group can either be reduced to an OH group, resulting in
C9H13N:
C12H15NO+
NaBH4 → C12H16NO+ NaOH
C12H16NO+ NaOH →
C9H13N+ NaOH +
H2O
or it can undergo reductive amination, resulting in
C10H15N.
C12H15NO+
NH3/NaBH3CN+ NaOH →
C10H15N+
H2O
Interestingly under the right conditions both can be formed in a single reaction!