A new and efficient method for the synthesis of rocuronium bromide

A new and efficient route for preparing 2β-(4-morpholinyl)-16β-(1-pyrrolidinyl)-5α-androstan-3α,17β-diol (6) as the key intermediate for providing rocuronium bromide (7) was developed. The overall yield of compound 6 in 5 steps increased to 57.8%, which was higher than currently reported methods Extraordinarily, this method could avoid the generation of disubstituted impurities E and F which are difficult to remove.