Patent / 1973
Corticosteroid 21-sulfates and 21-phosphates
Diidopregnadienedione I (R = R1 = I) (II) was treated with Me2CO contg. K2HPO4 and H3PO4 or MeCN-Me2CO contg. Et3N.H3PO4 to give betamethasone phosphate (I; R = H, R1 = OPO3H2), which yielded 1:1 and 2:1 salts with PhCH2NHCH2CH2NHCH2Ph. Treatment of II with K2SO4 and H2SO4 yielded betamethasone sulfate (I, R = H, R1 = OSO3H).