The invention relates to the technical field of pharmaceutical chemicals, in particular to a preparation method of 11beta, 17alpha-dyhydroxyl-6 alpha-methylpregna-4-ene-3, 20-
diketone, and discloses a preparation method of 11beta, 17alpha-dyhydroxyl-6 alpha-methylpregna-4-ene-3, 20-
diketone. The method comprises the following steps: S1, adding a 11beta, 17alpha-dyhydroxyl-6 alpha-methylpregna-4-ene-3, 20-
diketone crude product into a
mixed solution of a
solvent A and a
solvent B, heating to 25-35 DEG C, and stirring for dissolving until the solution is clear, so as to obtain a 11beta, 17alpha-dyhydroxyl-6 alpha-methylpregna-4-ene-3, 20-diketone crude product; s2, carrying out transposition
elimination reaction; s3, carrying out acidification deprotection reaction; s4, adjusting the pH value; s5, standing and layering; s6, decoloring; s7, performing concentration; s8, cooling and crystallizing; s9, carrying out
solid-liquid separation; and S10, carrying out
vacuum drying, so as to obtain a finished product of the 11beta, 17alpha-dyhydroxyl-6 alpha-methyl pregna-4-ene-3, 20-diketone. The method has the characteristics of high yield and good product quality, is stable and is easy to realize industrial production.