A method fosaprepitant dimethoxy dimeglumine prepared

The present invention discloses a process for preparing structural formula I as shown fosaprepitant dimethoxy dimeglumine method, the method of synthetic route is shown below, includes the following two steps: (1) The compound bis (diphenylphosphino methyl) phosphoryl chloride (formula III) and aprepitant (formula II) at the bit hindered strong base, generating a new intermediate phosphorylated product (formula IV); (2) the new compounds by catalytic reductive deprotection to give fosaprepitant diphenylmethane, simultaneously with deprotection -D- N- methyl glucamine salt formation into the desired product. The method uses two phosphorylating agent having large steric protective group, due to steric hindrance effect of enhancing the stability of the selectivity of the first reaction zone and intermediates, thus the present invention not only enhances the intermediates stability and increasing the yield of the reaction.