The invention discloses a preparation method of dihydro-oat
alkaloid, which comprises the following steps: S1, preparation of p-hydroxyphenyl
propionate, S2, preparation of a dihydro-oat
alkaloid crude product, and S3, preparation of a dihydro-oat
alkaloid competitive product.The amine ester exchange catalyst is preferably concentrated
sulfuric acid and p-toluenesulfonic acid, so that the reaction is more facilitated; although the
raw material has an
aniline structure and can form
aniline salt at low temperature, when the temperature is higher than 120 DEG C, the unstable
aniline salt can be dissociated and continuously participates in the reaction, so that the conversion rate of the
raw material is increased; the amine ester exchange
solvent is preferably DMSO (dimethylsulfoxide) and
sulfolane, the two solvents have the properties of high
boiling point and good
solubility, and meanwhile, the solvents are low in
toxicity, have water
solubility, are simple in post-treatment, and are convenient for refining and purifying a dihydrooat alkaloid crude product; meanwhile, the preparation process is short in step, the yield of the two-step reaction is 80% or above, and industrial large-scale production is facilitated.