Process for preparing and purifying novel polymorphs of fosaprepitant intermediate

摘要

The present invention relates to a process for preparing fosaprepitant dimeglumine of the general formula. The invention also relates to a di-benzyl fosaprepitant intermediate and polymorphs thereof. The preparation process consists of the following steps: preparation of di-benzyl fosaprepitant of the general formula II in polymorphous form 1 from an aqueous solvent or a mixture of solvents; crystallization of the so formed di-benzyl fosaprepitant from a crystalline solvent after addition of a co-solvent to yield a polymorphous form 1 or 2 of di-benzyl fosaprepitant; and catalytic hydrogenation of the recrystallized di-benzyl fosaprepitant in the presence of N-methyl-D-glucamine in a hydrogenation solvent with subsequent isolation of the formed product.