Reductions

Since this is the most important step in the production of amphetamines, I have created a special section describing the preliminaries and techniques in great detail. After spending a lot of time
and money to synthesize your nitropropene, you will be greatly disappointed to find that following the directions given in a journal is not enough to create an active compound.
There are some minor pitfalls that many scientists figure all their readers already know about, but if they don't know about them, their reduction will fail miserably, wasting the their time and the chemicalsinvolved.
Although many formulas listed are designed specifically for reducing to amphetamine type
compounds, they should work well on other drug synthesis calling for reductions. After finding
a suitable or compatible reduction formula, replace the nitrostyrene or nitropropene, etc., with
an equimolar ratio of the compound you wish to reduce. If I explained everything that I would
like you to know about reductions, this chapter would be about 200 pages longer than it already
is; obviously I cannot say everything, so I will stick with the basics.
Reductions in organic chemistry utilizing zinc, iron, and hydrogen sulfide, have been performed
since the 1840's. Catalytic hydrogenation came about in 1897, and reduction with metal hydrides
came into usage in 1947.

REDUCTIONS WITH METAL

Zinc. Next to sodium, zinc is the most used reductant. It is available in powder, dust, and
granular (mossy) forms. Zinc gets coated by a layer of zinc oxide which must be removed to
activate it before it can reduce effectively. It can easily be activated by shaking 3 to 4 min. in
a 1% to 2% hydrochloric acid solution. This means for every 98 ml of water volume, add 2 ml
of coned hydrochloric acid. Then wash this solution with water, ethatiol, acetone, and ether. Ot
activation can be accomplished by washing zinc in a solution of anhydrous zinc chloride (a very
small amount) in ether, alcohol, or tetrahydrofuran. Another way is to stir 180 g of zinc in a
solution of 1 g copper sulfate pentahydrate. Personally, I like the HC1 acid method.
Mossy zinc is activated by converting to zinc amalgam by brief immersion in amalgam solution.
(Use 40 g mossy zinc immersed in 4 g mercuric chloride, 4 ml concentrated HC1 acid, and 40
ml of water.) This type of amalgam can be used with powdered zinc also.
Reductions with zinc are very effective on aromatic nitro compounds using organic solvents
and an acid medium at around 50-70°, No matter what kind of metal is used, good stirring is
a must. After the reaction is over, the zinc is filtered off, care being taken not to let it become
dry, as it is pyrophoric. Also, be careful while disposing of zinc for the very same reasons.

Vogel