The present invention is applicable to the technical field of chemical
drug synthesis, and provides a preparation method of
halcinonide intermediate, comprising the following steps: adding
acetic acid to anecortave acetate in an
organic solvent, reacting under the common
catalysis of p-toluenesulfonic acid and
trifluoroacetic anhydride, adjusting the pH value with
ammonia, separating, washing, concentrating under reduced pressure, beating, filtering, and
drying to obtain D-1; adding D-1 to
dimethyl sulfoxide, reacting under the
catalysis of
potassium acetate, cooling, precipitating a
solid, filtering, and
drying to obtain D-2; adding an
aqueous solution of
sodium hydroxide or
lithium hydroxide to D-2 in a reaction
solvent, and hydrolyzing the reaction to obtain D-3; reacting D-3 with an
acyl chloride in an aprotic
solvent under alkaline conditions to obtain D-4; adding D-4 to DMF, and reacting with
lithium chloride under
nitrogen protection to obtain D-5. The
raw material anecortave acetate used in the present invention is easily available and cheap, and the method for preparing D-5 is efficient, green, safe, and has a high yield.