Method for manufacturing ephedrine or pseudoephedrine and ephedrine or pseudoephedrine intermediate

A method for manufacturing an ephedrine or pseudoephedrine intermediate, comprising: using 2-chloropropionyl chloride and benzene as starting raw materials and performing a Friedel-Crafts reaction using a Lewis acid catalyst to generate 2-chloro-1-phenyl-1-propanone; and reacting the generated 2-chloro-1-phenyl-1-propanone and methylamine in an aprotic solvent to generate 2-methylamino-1-phenyl-1-propanone. Further provided is a method for manufacturing ephedrine or pseudoephedrine. The method does not use the highly polluting phosphorus trichloride, and does not use the extremely hazardous and expensive bromine. The Friedel-Crafts reaction and amination reaction are completed within a single solution, reducing infrastructure cost. The invention thereby provides a safe, simple, low cost, and environment-friendly method for synthesizing ephedrine and pseudoephedrine.