Ephedrine from Methyl Phenyl Di-ketone

The methyl phenyl di-ketone, sometimes called 1-phenyl, 1,2-propanedione, which would be the di-ketone used for condensation with methylamine and the subsequent hydrogenation in the presence of a catalyst to produce ephedrine, is known, as are certain other diketones. 

When the hydrogenation is completed, which is indicated by the fact that no more hydrogen is taken up, air is admitted whereupon the catalyst readily coagulates, and may be removed by filtration. The filtrate is evaporated, preferably under reduced pressure, to a small volume is made faintly acid with hydrogen chloride and is evaporated again whereupon on cooling, ephedrine hydrochloride usually separates out as a white crystalline salt, which is separated from the liquid This crystalline salt consists mainly of racemic ephedrine hydrochloride, with a relatively smaller amount of racemic pseudoephedrine hydrochloride. These may be separated by known methods, as by fractional crystallization from chloroform. A substantially pure racemic ephedrine hydrochloride may thus be obtained, whose melting point is about 186° C. The racemic ephedrine hydrochloride has the formula  

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