The invention relates to a preparation technology for
dexamethasone sodium phosphate. The preparation technology comprises the following steps: a ring-opening reaction is carried out, namely,
dexamethasone acetate
epoxide is employed as an initial
raw material, HF and DMF are added, a reaction is performed for 3h, a ring-opening reaction is carried out and a
dexamethasone acetate solution is prepared; recrystallization is carried out, namely,
acetone or
ether is added in the
dexamethasone acetate solution, recrystallization is carried out,
dexamethasone acetate is prepared, and rotary
distillation is employed to remove the
solvent after recrystallization; base
catalysis hydrolysis is carried out, namely,
dexamethasone acetate is added in Na2CO3 and
methanol, a reaction is carried out for 10min, dexamethasone is prepared; pyrophosphoryl
chlorine esterification is carried out, namely, dexamethasone is reacted with pyrophosphoryl
chlorine and THF, and dexamethasone
phosphate ester is prepared; a
neutralization salt forming reaction is carried out, namely, the dexamethasone
phosphate ester obtained from the fourth step is reacted with NaOH and
methanol, and
dexamethasone sodium phosphate is prepared. The steps are simple, raw materials are easily available, the
reaction conditions are mild, the preparation technology is suitable for industrial production, and the cost is low.