The invention relates to a method for preparing a safe and effective antibechic dimimorfan
phosphate. The method comprises steps of reacting dextrorphane with trifluoro-methylsulfonyl
chloride in
triethylamine so as to generate dextrorphane trifluoro-methyl
sulfone chloride ester; reacting the dextrorphane trifluoro-methyl
sulfone chloride ester with tetramethyltin in methylbenzene so as to generate (9s, 13s, 14s)-3, 17-dimethyl
morphinan (or adding the dextrorphane trifluoro-methyl
sulfone chloride ester into mixed
solvent of THF and N-methyl-2-pyrrolidone, adding catalyst
ferric acetylacetonate and methyl
magnesium bromide, stirring and heating
reflux for 12 hours, so as to prepare (9s, 13s, 14s)-3, 17-dimethyl
morphinan), furthermore, reacting with
phosphoric acid so as to salify to prepare target product (9s, 13s, 14s)-3, 17-dimethyl
morphine phosphate-dimimorfan
phosphate. The method takes commercially available dextrorphane as the
raw material, and prepares the target product through three steps of esterification,
methylation and salification. The method has advantages of easily obtained raw materials, few synthesis steps, simple technology, low cost, high yield, high purity of the product and strong economic practicability, and is applicable to industrial production.