The invention relates to a method for preparing 17alpha-
hydroxyprogesterone. The17alpha-
hydroxyprogesterone is prepared by taking 17beta- cyano-5-androstene-17-ol-3,3-diethylene ketal (referred as an intermediate II) as a
raw material and dimethylzinc or methylzinc
chloride as a
reagent; the content of the 17alpha-
hydroxyprogesterone by HPLC is above 99.5% and the weight yield is 83-87%. The method comprises the following steps of dissolving the intermediate II in an
organic solvent, adding
lithium chloride as a catalyst, stirring, raising the temperature to 40-80 DEG C, dropwise adding a
toluene solution of dimethylzinc or methylzinc
chloride of which the concentration is 2M, and continuing to complete the reaction; and then adding an
ammonium chloride solution of which the concentration is 25% to destruct an organic
zinc reagent, separating the aqueous layer out and extracting, merging the
organic layer and the extract and concentrating the
solvent to near
dryness, and then adding lower
alcohol, stirring, raising the temperature to 40-60 DEG C, adding the acid of which the concentration is 2M, hydrolyzing, adjusting the pH value with a
weak base after the reaction is completed, evaporating 90% of the
solvent out, adding
tap water, cooling and crystallizing to obtain a crude 17alpha-hydroxyprogesterone product; and then carrying out
reflux decolorizing on the crude product with
activated carbon by virtue of
alcohol, and refining to obtain the commercial grade 17alpha-hydroxyprogesterone. The 17alpha-hydroxyprogesterone produced by the method disclosed by the invention has the advantages of good purity and high yield and is economic and environment-friendly, and the
solvent can be recycled.