08-06-04 03:49
No 523915
The two methods I am comparing are:
Methamphetamine Synthesis. by Benzylmagnesium Chloride Alkylation of Acetaldehyde
Methylimine. by Leno Latrunculus (../rhodium/grignar
(Refered to hereafter as "SWIL's method")
and
Post 202649 (Rhodium: "Meth via grignard rxn (Gazz Chim Italiana)", Novel Discourse)
(Refered to hereafter as "The Italian method")
SWIL proposes using methylamine hydrochloride, instead of the freebase as proposed in the literature. Also, unlike the Italian literature, he does not propose the use of sodium sulfate or any other drying agent to remove water formed in the imine reaction.
However, these "simplifications" seem to help the reaction, rather that hurt it; the Italian method claims only a 40% yield, while SWIL claims an 87% yield.
Other than the differences noted above, the two procedures seem similar. Why, then, the much higher yield in SWIL's method? Does the use of the hydrochloride salt rather than the freebase have anything to do with it? Also, how can the imine form properly in SWIL's method if there is nothing to take away the water?
