The preparation method of ephedrine or pseudoephedrine and ephedrine or pseudoephedrine intermediate

The invention discloses the preparation methods of a kind of ephedrine or pseudoephedrine intermediate, comprising: using 2- chloro-propanoyl chloride and benzene as starting material, under Louis acid catalysis, carries out friedel-craft reaction, generates 2- chloro-1-phenyl -1- acetone；2- chloro-1-phenyl -1- acetone, the methylamine of generation are reacted in aprotic solvent and generate 2- methylamino -1- phenyl -1- acetone.The present invention discloses a kind of methods for preparing ephedrine or pseudoephedrine.This process no longer uses seriously polluted phosphorus trichloride, the no longer very big and expensive bromine using risk.And friedel-craft reaction and methylamine reaction are completed in the same solvent, save the spending of public work.To provide a safe, simple and direct, inexpensive, green ephedrine and pseudoephedrine new technique for synthesizing method.