Synthesis of Betamethasone Dipropionate

OBJECTIVE Synthesis of betamethasone dipropionate. METHODS The betamethasone dipropionate was synthesized from betamethasone through acid catalysis cyclization, selective hydrolysis and 21-acylation. RESULTS The structure of product was identified by IR, ¹H-NMR, ¹³C-NMR and MS, the total yield was 76.4% and the HPLC purity was 99.56%. CONCLUSION The synthetic process is simple, easy to control and suitable for industrial production.