Novel One Pot Amphetamine synth from BzCN, MeMgI and NaBH4 (by Rhodium)

The alkylation of benzyl cyanide (phenylacetonitrile) with methylmagnesium
iodide affords Phenyl-2-iminopropane, which is directly reduced with NaBH4 
without isolation of the intermediate to give DL-phenyl-2-aminopropane. 
The same procedure with Benzylmagnesium chloride and acetonitrile will 
yield the same intermediate imine, but certain rearrangement by-products 
are possible in the latter case. 

A solution of MeMgI was prepared in the usual manner from methyl iodide 
(15g, 0.105 mol) and clean Mg turnings (30g) in 200ml dry THF, and the solution 
was added slowly with good stirring to a cooled solution of (11.7g, 0.1 mol) 
benzyl cyanide in 150ml dry THF in a dried 1000ml round-bottomed flask. 
The reaction mixture was stirred at room temp for two hours and then cooled 
in an ice-bath. The solution was diluted with 150ml of dry methanol and NaBH4 
(9.5g, 0.25 mol) was added in portions during 30 minutes, and the reaction 
mixture was stirred for another hour. The reaction mixture was concentrated 
under vacuum and the residue dissolved in 200ml water and acidified with 
concentrated HCl. The solution was washed with 2x50ml DCM, made basic through 
the addition of 25% NaOH, and extracted with 3x75ml DCM. The pooled organic 
extracts was dried over MgSO4, filtered and the solvent evaporated under 
vacuum. The oily residue was then vacuum distilled to give DL-Amphetamine 
as a clear oil (bp 82-85°C at 13 mmHg). 

Yield 10.8g (80% of theory).

Ref: JACS 109, 3378-3387 (1987) Procedure adapted from the synthesis of #49.